1

INCREASING OUTPUT THROUGH REDUCTION OF MACHINE UNPRODUCTIVE TIME AT THE BLACK SLIDE MACHINING PRODUCTION LINE OF T&S

LASER SOLUTIONS, INC. (TLS), STO.TOMAS BATANGAS

MARY ELAINE MANALO MARANAN 2005-48499

A PRACTICUM STUDY PRESENTED TO THE FACULTY OF THE DEPARTMENT OF INDUSTRIAL ENGINEERING COLLEGE OF ENGINEEERING AND AGRO-INDUSTRIAL

TECHNOLOGY UNIVERSITY OF THE PHILIPPINES LOS BAÑOS IN PARTIAL FULFILLMENT OF THE REQUIREMENTS

FOR THE DEGREE OF

BACHELOR OF SCIENCE IN INDUSTRIAL ENGINEERING

APRIL 2010

1

1. INTRODUCTION

2

1.1. Overview of the Company

T&S Laser Solutions, Inc. (TLS) is a manufacturing company that provides

laser cutting and machining services. It is a Filipino company that is backed by

Japanese expertise and technology in the laser and cutting field.

TLS has two operating sections within its manufacturing site: the laser

cutting section and the machining section.

The laser cutting section provides solution to companies that have metal

cutting as a part of their manufacturing process through the use of laser

technology. Its services include development cutting, laser marking, laser

sculpting, and laser engraving. The machining section on the other hand,

manufactures different type of gun slides as part of the product owned by the

Arms Corporation of the Philippines (Armscor), one of its main customers.

The laser cutting section operates on a single 10-hr-shift working schedule

during weekdays while the machining section works on a two 11-hr-shift rotation

structure from Mondays to Saturdays.

1.1.1. Company History

T&S Laser Solutions, Inc was established in the year 2006. It is a

member of T&S Global Solutions (TGS), to where the company, with the

other two members started. TGS began from a 12-man operation in 2004

until it grew steadily into a 60-man company of highly skilled engineers.

The two related companies are Philippine Tsugami T&S (PHITTS) and

Crossworld Buiness Solutios, Inc. PHITTS is an industrial machine

maintenance service provider which offers equipment calibration, equipment

repair and non-destructive testing and which provides the maintenance of

the equipment in the company. Crossworld Business Solutions is a

consulting firm providing services in assurance, investment planning,

corporate finance, accounting outsourcing, tax and technology consulting.

TLS is supported by its mother company – TandS, Inc. that is

located in Japan and has been in the industry for two decades. TLS started

3

as a provider of laser and cutting services only. It was only in August, 2008

when it started its machining operations.

1.1.2 Organizational Structure

Figure 1-1 shows the organizational structure of the company. The

company is made up of four major departments namely: Administration and

Accounting, Sales and Marketing, Laser Cutting Division, and Machining

Division. The laser cutting and machining divisions incorporate the

production section of the company with three workers and eight operators

respectively.

TLS employs 25 people in total. The laser cutting has three

operators while the machining division has eight workers including the

operators and the machinists.

The president oversees the overall operations of the company and

for each of the department a concerned head is assigned for supervision.

The vice presidents act also as the manager of the laser cutting and the

machining sections. The sales and marketing officer is the one in charged

with dealing with present and potential customers. The administration and

accounting department deals with the accounting system of the company

and serves also as the Human Resource Department.

4

Figure 1-1 Organizational chart of the company

5

1.1.3 Company Location

T&S Laser Solutions, Inc. is located at the First Philippine Industrial

Park in Sto. Tomas, Batangas. Figure 1-2 shows the location map of the

company.

Figure 1-2 Location map of the company

1.1.4 Customers Served

TLS offers its laser cutting services and machining services to

companies that require cutting and machining processes in their production.

Some of the industries it serves are advertising, architectural design,

aerospace/auto parts manufacturing, chemical engineering, construction,

electronics, machinery/equipment manufacturing, tooling, metal forming,

precision engineering, and semiconductor industries.

Some of its customers are Advantek, Philippine Yushin, Cebu

Yushin, Arms Corporation of the Philippines, and Babcock-Hitachi of the

Philippines, Inc.

BATANGAS

STO.TOMAS

TLS

6

1.1.5 Industrial Classification

TLS is considered a manufacturing company as it is involved in the

fabrication and machining of product parts that companies use in their own

manufacturing processes. Aside from manufacturing products and product

parts it is also a service provider of aesthetic and design services.

1.1.6 Lines of Products/Service

The company offers a wide range of products to other manufacturing

companies. Some of the products it produces are channels, ducts, casings,

base plates, washers, flanges, storage, spacers, signages, logos, keychains,

links, slides, machine parts, etc. It also provides aesthetic and design

services through laser marking, sculpturing and engraving. These are all

done in the laser cutting section. Through its machining operations, it

produces gun slides as part of products of the Arms Corporation of the

Philippines. Figure 1-3 shows some of the company’s (a) services and (b)

products.

Figure 1-3 Sample products and services

1.2. Background and Significance of the Study

One of the competitive advantages a company can gain over its

competitors is meeting customer demand. It is not only a means to achieve

higher sales but also to protect the reputation of the company and to build a

strong relationship with the customer. As much as manufacturers want complete

7

and readily available resources in producing their products, customers also do

not want insufficient delivery of their orders.

One way of meeting demand is increasing capacity. It may be through

adding more machines, hiring more workers or making sure that materials are

available at the start of production. But these are necessary if it is the maximum

capacity that cannot meet the demand. On the other hand, a company can meet

customer demand by making sure that the current capacity is utilized efficiently. It

means no unproductive time is present at the system or at the least, it is

minimized.

For TLS, who is new to the industry of machining metals, meeting its

customer’s demand is a good approach to create a good name in the industry.

One main source of income of the company is the machining production

line where the proponent of the study was assigned. The line is producing three

different types of slides namely: black slide, rough slide, and smooth slide. These

products were named as such for confidentiality purposes. Figure 1-4 shows the

distribution of product output in the machining production section.

Figure 1-4 Product output distribution of the machining production section

8

As shown, the major income of the machining production section comes

from black slides. But in its production period for five months it did not meet the

fixed monthly demand of 2800 units. Figure 1-5 shows the actual outputs of the

black slide production line for five months in the year 2009 and the monthly

demand.

Figure 1-5 Demand and actual output of the black slide machining line

Relative to the demand of the black slide production line, the actual outputs

are lower. The average monthly output of the line is 2471 units (see appendix A).

This causes lost sales to the production that is equal to 329 units per month or

equivalent to Php1, 101, 492 per year (refer to appendix B). Assessing the

capacity of the black slide production line, it was determined that the line is

capable of meeting the demand. The line capacity assessment was further

discussed in the results section. Table1-1 shows the line capacity assessment of

the black slide production line.

9

Table 1-1 Monthly capacity per process

Process Effective Capacity per

month(units)

Facing –off 5668

Drilling 3276

Milling Ref 3952

Milling Clearance 5668

Stop seat 3952

Stop slot 3250

Milling Barrel 3250

Pre drilling 3276

The stop slot process has the lowest capacity with 3250 units per month.

Since it is the bottleneck process, it will determine the maximum output or the

effective capacity of the whole line. Comparing it to the monthly demand of 2800

units, the capacity is higher, thus it can meet the demand. This means that there

are problems in the operation which contribute to low production output of the

line.

One area for improvement identified is the presence of unproductive time in

the production line of black slide. It was verified through continuous lapse time

method that the production line is having significant machine unproductive time.

Figure 1-6 shows the breakdown of production time in the black slide machining

line.

Figure1-6 Breakdown of production time

10

Unproductive time accounts for 22% of the available production time in the

morning shift. The data were obtained only from the nine hours in the morning

shift. The unproductive times recorded were the times when the machine is not

working either having downtime or idle time which in effect reduce the potential

output of each process. This was computed to be equivalent to production loss

of 22 units per day or 364 units per month. This was further discussed and

shown under line capacity assessment in the results section. Reducing the

unproductive time can therefore increase the output of the line by reducing the

production loss.

Also, the company gives additional 25% of the regular wage per hour for

overtime. In total, it pays regular overtime cost equivalent to Php148, 200 in a

year for all the four operators working in the black slide production line (see

appendix B). Thus, reducing the unproductive times cannot only increase the

company’s production output, it can also reduce or eliminate the need for

overtime schedules. Doing so would mean reduced costs for the company.

1.3. Statement of the Problem

High machine unproductive time was observed in the black slide machining

production line. It was identified as an area for improvement since the production

line cannot meet its monthly demand of 2800 units. The unproductive time was

verified to cause a significant loss in the production which limits the potential

maximum output to be achieved. The unproductive times include having

inefficient performances, poor workplace, non-standardized working procedures

and worker delays.

1.4. Objectives of the Study

The general objective of the study is to reduce machine unproductive time

in the machining production line of Black slides to increase its output.

Specifically, it aims to

• describe the current production system of black slide;

• identify the factors contributing to the machine unproductive time in

the line and its impact to the system;

• analyze these factors and establish solutions to it;

11

• evaluate the solutions formulated;

• develop the best solution to the problem;

• make further improvements to the system; and

• Apply Industrial Engineering tools and concepts as aid in analyzing

and solving the problem

1.5. Scope and Limitations

The study is limited to the Black Slide products. The operations under study

limit to the manufacturing process of Black Slides under the machining

production section. Due to morning work schedule, the time samples were

obtained for nine hours only from the morning shift. Late deliveries of raw

materials were not considered due to time constraints.

1.6. Date and Place of the Study

The study was conducted at the Black slide production line under the

machining production section of T&S Laser Solutions, Inc. at the First Philippine

Industrial Park, Sto. Tomas Batangas. The study covered the period May 2009 to

March, 2010.

1.7. Roadmap/Milestone

Figure 1-7 shows the Gantt chart schedule of activities done during the study.

Figure 1-7 Gantt chart schedules of activities.

12

2. METHODOLOGY

13

2.1. Procedures

The study started with the preliminary gathering of data. Actual observations

on the manufacturing processes, the operators and machine operations were first

done in order to familiarize with the production system. Initial gathering of data

was done through interviews with the operators, supervisors, and the production

engineer. Some pertinent and significant information in the form of brochure,

slides, and other printed materials were also secured from the company.

Through further gathering of data using continuous lapse time method,

unproductive times were present in the production. This became the initial

foundation of the problem. To verify if the unproductive times affect the

production, the machines were continuously observed and the unproductive time

at each process were recorded with their corresponding lapse time. Time study

was also done to determine processing times for the evaluation of the current

system including production capacity.

All the data gathered were used then for the analysis. The time samples

were used to determine the normal time for each process and to compute the

effective capacity of the line. The time records were used to determine the

percentage of machine unproductive time in the production. When the problem

was fully established, root-cause analysis and CNX analysis were used to

identify and group the factors that contribute to the problem.

Direct and alternative solutions were then generated to solve the problem.

The alternative solutions were evaluated based on selected criteria. Cost and

benefits of the best solutions and recommendation were discussed. All the

results of the study were then summarized and finally, recommendations were

presented along with the other areas for further study.

2.2. Definitions of Terms

The terms in Table 2-1 along with their definitions were used in the study.

14

Table2-1 List of defined terms used in the study

Term Definition

Actual Capacity Output of a line when unproductive

times are considered

Avoidable delay

Delay that can be controlled/avoided

(e.g. chatting, loitering)

Bottleneck process The process with the minimum capacity

Cycle time Total time spent by the material in a

workstation

Effective capacity The maximum possible output less set

up times and break times

Effective time The maximum available production time

Frequency (ƒ) The number of occurrence of an

element or process

Machine Idle time Time when the machine waits to be

attended

Machine Downtime Time when the machine is not working,

(e.g. when under repair)

Normal Time (NT) Observed time adjusted for worker

performance

Performance Rating (PR) Rating of the work performance of

operator

Relaxation Allowance (RA) Also rest allowance of workers

(including break times)

Standard Time Time required to perform a task

Unit normal time (UNT) Normal time of a process per unit, also

the processing time

Unproductive time (UT) Time when no output is produced (e.g.

downtime, idle time)

15

2.3 Description of Symbols

The following symbols in Table 2-2 were used in the study.

Table 2-2 Symbols used and their description

16

3. SYSTEMS DOCUMENTATION

17

3.1 Product Focus of the Study

The study considered the slide products that are produced in the machining

production section of the company.

There are three types of slides produced in the machining production

section. These include (a) Black slide, (b) Rough slide, and (c) Smooth slide. The

different types of slides are shown in Figure 3-1.

Figure 3-1 Slides Manufactured in the Machining Production Section

The study solely focuses on the Black Slides. All of the three slides belong

to product line of Arms Corporation of the Philippines but only Black slide has the

continuous production. The production output contribution of each product was

previously shown in the background and significance section.

3.2 Black Slide Manufacturing Process

In general, there are eight major operations in manufacturing of the Black

Slide products, namely: Facing-off; Drilling, Milling Ref, Milling clearance, Stop

seat, Stop slot, Milling Barrel, and Pre-drilling. Figure 3-2 shows the flow of

processes for Black Slide production.

(a).

(c).

(b).

18

Figure 3-2 Manufacturing Process of Black Slide

These major operations are the names of machine operations. As shown

in the figure, the processes are grouped per workstation. Four machines are

regularly used in the production of Black slide and in each machine, two

processes are performed. Because of limited number of machines, one of the

two processes in the same workstation is performed after the other process.

Work-in process units are allowed in each workstation.

Aside from machine operations, there are also independent manual

operations performed. These include filing before loading, filing after unloading,

and inspection. Figure 3-3 shows the process flow in each workstation.

19

The materials are filed first before they are loaded to the machine. This

process is done to prevent poor feeding of machine cutter. The materials are

then loaded and clamped tightly to the jig inside the machine. Once clamped, the

operator will start the machine to run. After the machine operation, the materials

are unclamped and unloaded to the table in front of the machine. They are then

filed again to smoothen sharp faces and to remove metal chips produced by the

machine operation. The materials are then inspected but only samples were

taken for the inspection process.

3.3. Facility Layout

The facility layout of the company is shown below in Figure 3-4.

Figure 3-3.Process flow chart at each workstation

20

MAIN SECTIONS :

Machining

Laser Cutting

Administration/Management

Figure 3-4 Facility layout of TLS

21

The darker green-colored area represents the administration and accounting

department of the company. The area with color light green represents the

machining production section. The dark blue-colored area represents the laser

cutting production section. Other colored parts of the layout represent areas such

as pantry (gray), pathway (light blue). The white-colored sections represent the

machines the company has. At the upper right section of the machining area is

where Black slide products are manufactured and the lower right area represents

the production section for other slide products of the machining section. The

surrounding area colored flesh shows the boundary of the building of the

company.

3.4 Production Operation Schedule

TLS, Inc. currently employs 3 workers in the laser cutting section and eight

workers in the machining section including the operators and the machinists, four

of who are assigned in the production of Black slides. The company is operating

on a two 8-hr-shift working schedule in the machining section with two operators

in each shift. The machining production works from Monday to Saturdays. For

the laser cutting section, the production works only during weekdays and on a

single 10-hr-shift. The company allows a one-hour lunch break and a 30-minute

break time for the laser cutting and the machining section. The company also

permits an overtime of 3hrs per shift for the operators in the machining section.

3.5 Manpower Complement

Currently, T&S Laser Cutting Solutions, Inc. is run by 25 people of which

three are workers on the laser cutting section, one operator, one production

assistant, and one quality analyst. The operator operates the machine, and the

quality analyst inspects if the finished goods conform to the design and

specifications of the product. The production assistant tasks include deburring or

filing, packaging and assistance in loading and unloading of the materials from

and to the machine.

In the machining section, four are operators who are assigned in the Black

slide product line and four are machinists assigned in other machining

operations.

22

3.6 Machines and Equipment

The laser cutting section uses the AMADA FO 3015 (3600 KW 5’ x 10’ bed)

machine in producing its goods and services. This machine maximizes utilization

with minimal set up between jobs. It supports its production with a crane used in

transporting of big raw materials from the material section to the machine bed.

They have manual calipers but use digital calipers in the inspection of the

finished product. They also uses height gage for inspection in processes such as

milling clearance, stop seat, stop slot, milling barrel, and pre drilling.

The machining production division has four CNC machines for

manufacturing of Black slide products and three machines for forge slides and

full slides. The company also has equipment for heat treatment of smooth slides.

Each of the machines performs two processes and each process has different

capacities. Table 3-1 shows the number of units that can be output per process

and the machine number where each process is performed.

Table 3-1Output per Process

Machine No. Process

Output per loading/unloading (units)

1 Face-off 4

2 drilling 4

3 milling ref 4

1 Mill clearance 1

3 Stop seat 2

4 Stop slot 4

4 milling barrel 4

2 Pre drilling 6

23

4. RESULTS AND DISCUSSION

24

4.1. Problem Identification

The black slide machining production line does not meet the monthly

demand of 2800 units which cause production lost sales amounting to 329 units

per month or is equivalent to Php1, 101, 492 in a year.

Since high machine unproductive time was observed and verified in the

production, it was identified as an area for improvement in order to increase the

output of the black slide production line. Figure 4-1 shows the machine

unproductive time occurring at each process.

Figure 4-1 Machine unproductive time at each process

The stop slot process has the highest recorded machine unproductive time

with 111.62 minutes per day. Several causes were determined to contribute to

the machine unproductive time in the black slide production and these include

double filing, machine adjustment, late filing, transport delays and worker delays.

Figure 4.2 shows the top causes of machine unproductive time in the black slide

machining production line.

25

Machine unproductive time per day

Percent

Causes

Count

Percent 41.4 13.9 11.0 10.5 10.0 6.1 4.9 2.2

Cum %

259.1

41.4 55.3 66.3 76.8 86.8 92.9 97.8 100.0

87.2 68.6 65.7 62.7 38.0 30.8 13.9

Tool wear out

No mat'l

Other tasks

Machine adjustment

Transport

File before

Double file

Worker delay

700

600

500

400

300

200

100

0

100

80

60

40

20

0

Total Machine Unproductive Time per Cause

Figure 4-2Total machine unproductive time contribution of each cause

Worker delay has the largest contribution amounting to 259.1 minutes of

total unproductive time present in the whole operation in the production line (see

appendix C for average unproductive time at each process).

Five causes constitute the 86.8 percent of the total causes of machine

unproductive time. Using Pareto principle these causes will be the focus of the

analysis and recommendations of the study. These causes include worker

delay, double filing, filing before or late filing, transport delay and machine

adjustment.

To verify the effect of the recorded machine unproductive time on the

capacity of the production, the capacity of the line was determined and was

analyzed.

26

4.2. Analysis

4.2.1. Time Study Results

Time study was done to determine the effective capacity of the

black slide machining production line and to have values of processing

times since these are necessary in the analysis of the problem.

Twenty time samples of each process were initially taken (see

appendix D for the initial samples). The processes timed are initial filing or

filing before loading, loading, machine process, unloading, filing after

unloading, and inspection. Outliers or samples whose values are far from

the average time are removed and not considered. To get the required

number of samples, the following values were considered:

X – Average of the samples

PR – Performance rating of operators

NT – Normal time

ƒ– Frequency

UNT – Unit normal time

R - Range

N - number of samples required

To compute for the unit normal time, the equations below were used:

NT = X * (PR)

UNT = NT * ƒ

R = maximum time sample - minimum time sample

N = R/UNT

For each process, the average of the time samples was computed.

It was then multiplied to the performance rating derived using

Westinghouse Rating System (see appendix E) to get the normal time for

each process. The normal time was multiplied to the frequency of each

element or process to get the unit normal time. The range of time values at

each process was also obtained for the computation of the required number

of samples. The values were tabulated in appendix G.

27

The value of N was then computed using the formula given above

(Niebel, 2003) and then it was compared to the values appearing in the

table for N values (see appendix F for the table). In the initial result of N

values, the highest value equated to 0.36 (see appendix G). Interpolating

this value using the table, the required number of samples is 23.

To verify if this is the final required number of samples, three more

time samples for each process are added and then the same method is

applied again. The highest resulting value for N is still 0.36, thus 23

samples is the final required number of samples (see additional samples

and final N results in appendix H). Table 4-1 shows the resulting normal

time for each process or the processing time.

Table4-1 Unit normal time of each process

Process Name Unit Normal Time(min)

1. Facing –off 0.99

2. Drilling 5.4

3. Milling Ref 1.48

4. Milling Clearance 5.17

5. Stop seat 6.69

6. Stop slot 5.01

7. Milling Barrel 4.93

8. Pre drilling 4.39

For each process or element, the unit normal time was used as

the process time but only the unit normal time for loading, unloading, and

machine time were considered in determining the cycle time for each

process since filing before and after, and the inspection process are done

while the machine is running. This is because it is a standard procedure set

in the production. This is also because it is the effective capacity per

process that was computed.

28

4.2.2. Line Capacity Assessment

The black slide machining production line is operating 24 hours with

two shifts. The total available production time is 1440 in minutes per day.

The time allotted for breaks is 1.5 hrs per shift and the set up time is 5mins.

Given this operating schedule, the total effective time is 1250 minutes, with

the set up and break times already deducted. Since there are two

processes performed in each machine, the total production day is divided

into two processes.

In determining the effective capacity of each process, the equations

below were used.

For the two processes, facing-off and milling clearance which are both performed in machine 1, the values were computed as:

For facing off

= 16.07 % (of the total effective time)

For milling clearance

= 83.93 % (of the total effective time)

Getting the effective time and the effective capacity,

For facing off:

Effective time = 0.1607* 1250 minutes

= 200.893 minutes

Effective capacity = 121.48 min per day / 0.557 min

= 202.922 units per day

29

For milling clearance:

Effective time = 0.9027* 1250 minutes

= 1049.107 minutes

Effective capacity = 1049.107 min per day / 5.17min

= 202.922 units per day

Based on the results, the maximum output of each process is 202

units per day. The same method is applied to remaining processes and

table 4-2 shows the results.

Table 4-2 Summary of effective capacity per process

As shown, there are processes with the same output. These are the

processes that are performed in the same machine. It is expected since it is

the effective capacity or maximum finished output of a process that was

computed. Any difference in the output of the two processes would mean a

work in process unit and not a finished good because this unit underwent

one process but did not undergo the other process so to get the maximum

output, the output of the two processes should be the same. For instance, if

the output of facing-off process is greater than the output of milling

clearance then the milling clearance will dictate the maximum output

between the two processes. The same analysis was done with the

remaining processes.

Process Percentage

(%)

Effective time per day

(min)

Unit normal time (min)

Effective Capacity per

day(unit)

Face-off 16.07 200.893 0.99 202

Drilling 55.16 689.479 5.4 127

Mill ref 18.12 226.438 1.48 152 Mill clearance 83.93

1049.107 5.17 202

Stop seat 81.88 1023.562 6.69 152

Stop slot 50.4 630.03 5.01 125

milling barrel 49.6

619.97 4.93 125

pre drilling 44.84 560.521 4.39 127

30

Of all the processes, it is shown that Machine 4 dictates the

effective capacity of the line which is equal to 125 units per day or 3250

units per month.

Accounting for effect of machine unproductive time, for each

process the effective capacity would not be maximized due to such

unproductive time. To determine the actual capacity per process the

equation below was used:

For face-off:

Actual capacity = (200.893 min/day - 64.79 min/day) / 0.99 min/unit

= 137 units /day

Loss per day = Effective capacity - actual capacity

= 202 - 137

= 65 units / day

The same computation was applied to remaining processes and the results

are shown in table 4-3.

Table 4-3 Summary of actual capacity and loss per process

Process Per-

centage (%)

Eff time/ day (min)

Unit Normal time (min)

Eff Cpty / daY (unit)

Average machine UT/ day (min)

Actual Cpty / day (units

Loss / day (unit)

Face-off 16.07 200.9 0.99 202 64.79 137 65 Drilling 55.16 689.5 5.4 127 71.04 115 12 Mill ref 18.12 226.4 1.48 152 67.57 107 45 Mill

clearance 83.93 1049 5.17 202 76.98 188

14 Stop seat 81.88 1023. 6.69 152 59.8 144 8 Stop slot 50.4 630 5.01 125 111.62 103 22

milling barrel 49.6

619.9 4.93 125 99.86 105 20

pre drilling 44.84

560.5 4.39 127 74.26 111 16

*Eff -effective *Cpty - capacity

31

After the machine unproductive time is deducted from the effective

time for each process it resulted that the stop slot process has the lowest

actual capacity with 103 units per day. Since this is the bottleneck process,

it determines the capacity of the production line. From 125 units of effective

capacity, the actual capacity now is 103 units per day causing a loss of 22

units per day or 364 units per month. This loss represents the equivalent

value in units of machine unproductive time.

The discussion above focused on the capacities of each process

given the available effective time for each process. To evaluate manpower

capacity, and verify if it does not affect the capacity of the machine, the

formula for computing the number of machines an operator can handle was

used. The equation for number of machines is given below:

Where:

n = maximum number of machines that can be assigned to an

operator

a = concurrent activity time

b = independent operator activity time

t = independent machine activity time

Concurrent activities are those activities wherein both the operator

and the machine are involved. These include loading and unloading

process. Independent operator activities are solely the activities of the

operator and with no machine involved. In the production, these are the

filing process before loading and after loading, inspection, and traveling.

Independent machine activity refers to the activity of the machine alone.

Considering the first two processes, face-off and drilling, the average

loading time is 0.19 minutes, unloading time is 0.15 minutes, machine

operation is 2.86 minutes, filing time before loading is 0.105 minutes,

filing after is 0.14 minutes, inspection is 0.07 minutes, and the travel time

32

is 0.07 minutes. Face-off also has a cleaning process which takes 0.11

minutes.

a = 0.19+ 0.15 = 0.34 minutes

b = 0.105+ 0.14 + 0.11 + 0.07 + 0.07 = 0.495 minutes

t =2.86 minutes

To evaluate if the two machines can be handled by an operator, the

average times were used in the equation.

= 3.83 machines

This means that the operator can handle three machines and thus the two machines assigned to an operator will not have idle time because the operator can handle both machines.

For the rest of the processes, the same method was applied. Table 4-4 shows the average activity times and the number of machines the operator can attend to.

Table 4-4 Summary of number of machines an operator can handle

Concurrent Process a b t n

Facing -off and Drilling

0.34 0.495 2.86 3

Drilling and Milling Clearance

0.45 0.47 4.84 5

Facing-off and Pre-drilling

0.33 0.51 2.37 3

Milling Clearance and Pre-drilling

0.44 0.39 4.35 5

Stop slot and Stop Seat

0.49 0.485 5.37 6

Stop seat and Milling Barrel

0.49 0.595 5.32 5

Stop slot and Milling ref

0.41 0.57 2.84 3

Milling Barrel and Milling ref

0.42 0.59 2.79 3

33

Based on the number of machines computed, the operator can

handle more than two machines assigned to him on whatever two

processes are concurrently performed.

4.2.3. Root-cause analysis

To determine the possible root causes of the having high machine

unproductive times an Ishikawa diagram was used. The study considered

only three major sources including man, material, and method. Figure 4-3

shows the Ishikawa diagram of root-cause analysis.

34

Figure 4-3 Root-cause analysis of the problem

35

Figure 4-4 Root Cause - Man

Man

The operators cause unproductive time to the machine when the

machine has stopped working but it is not attended. Operators were

observed as frequently leaving the workplace either to go to the pantry to

drink water or to go to the comfort room. Since the pantry and the comfort

room are quite far from the workplace it takes the operators long time to get

back to the workplace. The possible cause of this is not enough rest

allowance for the operators which cause worker fatigue. Aside from leaving

the workstation, machines are not promptly attended because operators as

observed are chatting or workstation hopping during work and these cause

idle time of the machine. Operators are also having start-up delays which

36

cause late start of the production during resumption to work in the

afternoon.

Figure 4-5 Root cause - Material

Material

The insufficient number of filing tools and unloading tools causes

idle time to machines. The operators often spend time searching for the

tools before they can attend the machines. This problem is caused by lack

of tools in other workstations. One set of tools provided is used by an

operator for two workstations. Sometimes the tools are used and

misplaced by the other operator so the when the operator needs the tools,

he has to go to the other workstation to search the tools he needs causing

idle time of the machine. Searching of tools also give the operators

chances to do avoidable delays such as chatting.

37

Figure 4-6 Root cause - Method

Method

It was observed that the operators are doing improper working

practices which cause idle time of the machine. One of these is filing of the

material just when machine has stopped working. Based on the

computation of number of machines an operator can handle, the given the

elements or processes including filing before and after, loading, unloading,

and inspecting, the least number of machines he can handle is three. It was

previously discussed in chapter 4.2.2 in line capacity assessment. This

means that no machine idle times are expected because the operator can

attend the two machines assigned to him. This is also set by the manager

since the machines have long processing time. What often happens is that

the materials are filed just before loading the slides to the machine. This

practice adds up to the cycle time of the material and idle time of the

38

machine. The table used for filing in the stop slot and milling barrel

processes was also identified as another cause of machine unproductive

time. Because the height design of the table is not fit, the operator is having

difficulty in filing leading to late filing or filing just when the machine needs

the material. For other processes with table of fair height, the operators

were observed to not follow the procedures set and are having delays such

as chatting.

Another problem with the method is the inspection method. The

operators are having incorrect inspections. Due to this they have to stop

the machine and adjust its set up. This causes down time to the machine

being adjusted and idle time to the other machine that the operator

cannot attend to. The height design of the table used in inspection is the

factor identified which affects the performance of the operator.

The problem with double-filing of the slides also causes idle time to

the machine. Instead that the materials will already be loaded, the machine

waits for the material to be filed again. The operator just put the materials

that were already filed in the same table where the waste metal chips are.

In effect, the chips adhere to the slides so the operators have to file them

again before they load it to the machine.

4.2.4. CNX Analysis

The root causes were grouped into noise, controllable, and

experimental factors. Chatting of the operators was considered noise since

it is difficult to prevent and eliminate in the production system.

Controllable factors are factors that already have existing

procedures, rules or policies set by the management (Dalawampu, 2008).

These are also factors that can be instantly addressed (Bautista, 2008).

Table 4-5 shows the controllable factors that are identified with the

corresponding actions.

39

Table 4-5 Controllable factors and the corresponding action

Factors Actions

C1 Start-up delay Strict implementation of new policy on on-time start of production

C2 One set of tools for two workstations

Buy another set of tools

C3 Operator does not follow procedure

Strict supervision

Experimental factors as opposite to controllable factors, experimental

factors are factors that do not exist yet in the system or those that need to be

evaluated and improved (Dalawampu, 2008).

The factors identified as experimental are shown in table 4-6 with the

corresponding alternative solutions.

Table 4-6 Experimental factors and the recommended actions Factors Actions

E1 Leaving the workstation frequently

A. Schedule additional 30-min break time

B. Reschedule 15 min-break in the morning

C. Maintain current system

E2 Low height of the table for filing

D. Design table height for filing

E. Use the same table used in other workstations

F. Maintain current system

E3 Low height of the table for inspection

F. Design for average, the table height for inspection

H. Maintain current system

E4 Poor workplace I. Adapt 5S program

J. Maintain current system

40

4.2.5. Generation of Alternatives

To address the controllable factors direct solutions were

recommended. On the other hand, alternative solutions were generated for

the experimental factors.

Controllable Factor C1

To eliminate start-up delay, the Human Resource Department (HR)

should implement a new policy regarding starting the production on time.

The supervisor will be in charge of noting the operators who will violate the

policy.

This study proposes the department to conduct community works

such as tree planting or outreach programs. The HR department may

subject the operators who will violate the policy to joining to such activities.

The idea is just a proposal to the department and the policy as part of the

disciplinary actions is still under the decision of the HR department.

The implementation of a new policy would reduce machine

unproductive time caused by production start-up delay. Table 4-7 shows

the processes and the machine unproductive time due to start-up delays

that would be reduced at each process.

Table 4-7 Machine unproductive time caused by start-up delay Process Machine Unproductive Time

per day(min) Drilling 7.12

Mill clearance 6.76

Stop seat 6.27

Stop slot 6.04

Controllable Factor C2

Since the cause of transport delay is lack of tools at other

workstations, the production should provide a set of tools for each

41

workstation to prevent the operators from going to other workstations to get

and search the tools needed.

This action would solve the transport delays at each process. Table

4-8 shows the machine unproductive time caused by transport delay that

would be reduced at each process.

Table 4-8 Machine unproductive time caused by transport delay

Process Machine unproductive time per

day (min)

Face-off 9.86 Drilling 9.49 Mill ref 8.49 Mill clearance 6.54 Stop seat 4.44 Stop slot 10.42 Milling barrel 10.17 Pre drilling 6.25

This would incur an initial cost of Php630 per set of file hand tool

and Php120 per set of unloading tool with the total cost of Php750 (refer to

appendix K for estimated price).

Controllable Factor C3

Regarding procedure on filing at the right time, the supervisor

should strictly oversee the operators during work. Strictly overseeing means

he should direct the operators to perform and work properly whenever he

noticed that they are not following the right procedures. Use of posters may

be helpful to remind the operators of the correct working procedure but still

presence of the supervisor would force the operator to follow the

procedures.

This action would reduce machine unproductive time due to late

filing of materials. Table 4-9 shows the machine unproductive time due to

late filing.

42

Table 4-9 Machine unproductive time caused by late filing

Process Machine Unproductive Time

(min/day)

Face-off 4.25

Drilling 4.21

Mill ref 4.37

Mill clearance 6.16

Stop seat 4.29

Stop slot 4.92

Milling barrel 4.92

Pre drilling 6.23

The total machine unproductive time in the stop slot and milling

barrel process due to late filing are 21.42 minutes and 17.63 minutes

respectively (see appendix C). Comparing these to other processes’, these

are relatively higher because two causes were determined as influencing

late filing in these processes: not following working procedures and low-

height table.

To determine the machine unproductive time in these two processes

caused by not following procedure, the average of the machine

unproductive time recorded in other processes will be used. The average of

the machine unproductive time in the six remaining processes is equal to

4.92 minutes.

This will be deducted from the recorded machine unproductive time

in the stop slot and milling barrel process and the remaining unproductive

time will be considered the machine unproductive time due to the other

cause which is low-height table for filing. This was assumed because only

the stop slot and milling barrel make use of the low-height table for filing.

43

Experimental Factor E1

From the principle of ergonomics (Niebel, 2003), the number of hours that an operator must have for break can be computed through the equation:

Where: R.A. = percent of rest that a worker must have per shift

W = Energy expenditure due to work

The difficulty of work in the production line was considered

moderate. From the table of Energy Expenditure (see appendix J),

moderate work had an energy expenditure ranging from 5- 7.5 (kcal/min).

Computing for the relaxation allowance,

R.A. = 0.1869 = 18.69% of the total working hours

The production starts from 6:00 AM to 6:00 PM. The break time

allotted for the operators is 1.5 hours, one hour for lunch break and 30

minutes for coffee break. Evaluating the relaxation allowance given to the

operators,

= 0.125 or 12.5% of the total working hours

Comparing the standard and the actual relaxation allowance, the

actual RA is relatively lower which causes fatigue to the operators. The

study then considers the action of adding break time for the operators.

Alternative Solutions to Experimental Factor E1

The first alternative solution (A) to operator delay of leaving the

workstation is to add 30 minutes to break time. To compute for the

44

recommended relaxation allowance, the RA that was previously

computed was used.

Total working hours per shift = 12 hours

RA required = 0.1869*12 hours/ per shift

= 2.24 hours

As computed, the number of hours that should be allotted for

break of the operators is approximately 2 hours per shift. The company

then can schedule a 30-minute break at 9:00 AM, 1-hour lunch break, and

another 30-minute break at 4:00 PM in the morning shift.

This recommendation will therefore reduce machine unproductive

time due operator delay of leaving the workstation to drink or go to the

comfort room. Along with this, the supervisor should be strict with the

operators. Such activities should be allowed during the break time added

in the morning. Table 4-10 shows the machine unproductive time that will

be reduced caused by operator delay of leaving the workstation.

Table 4-10 Machine unproductive time caused by leaving the workstation

Process Machine Unproductive Time per Day

(min)

Face-off 26.16

Drilling 18.38

Mill ref 27.74

Mill clearance 18.47

Stop seat 17.64

Stop slot 22

Milling barrel 26.78 Pre drilling 22

The drawback of adding 30 minutes to the break time of the

operators is that 30 minutes will be reduced from the total effective

production time and thus the capacity of each process will decrease.

Accounting this on the computation of machine unproductive time

that will be reduced in each process the computation is shown below.

45

effective time per day = 1250 minutes

Less = 30 minutes

New effective time/day = 1220 minutes

For face-off process:

Percentage = 16.07 %

Processing time = 0.99 minutes/ unit

Effective time for this process = 196 minutes

Effective capacity = 196 /0.99

= 198. 0519 units/day

Due to additional 30 minutes to the break time, the effective time

for face-off was reduced to 196 minutes per day. This was obtained by

multiplying the new effective time for face-off by the percentage of face-

off process after 30 minutes were reduced from the total effective

production time. Since the machine unproductive time due to leaving

workstation was eliminated, the capacity of the process is now 198.05

units per day which would equate to the effective capacity since the

unproductive time is already eliminated. To determine the number of units

that can be produced in face-off when the unproductive time is eliminated

and 30 minutes is deducted from the effective production time, the

capacity of face-off after improvement was computed as:

effective time = 1250 minutes

Effective time for face-off = 200.893 minutes

Average UT due to leaving workstation = 26.16 minutes per day

Capacity before improvement = (200.893 – 26.16)/0 .99

= 176.498 units per day

Getting the difference of the two capacities computed, the number

of units that can be output with the reduced unproductive time in the face-

off process is 21 units. This value is not yet the final or the representing

number of units that can be increased in the whole production line when

the machine idle time due to such cause is eliminated. To determine it,

the same method was applied to other processes. Table 4-11shows the

result of reducing operator delay through addition of 30-minute break.

46

Table 4-11. Effect on process output of adding 30-minute break

Process

Effective time (min)

Capacity (unit/day)

Effect on the

output per day (unit) Before After Before After

Face-off 174.733 196.071 176.49 198.05 21.55

Drilling 671.099 672.932 124.28 124.62 0.34

Mill ref 198.698 221 134.26 149.32 15.06 Mill clearance 1030.637 1023.929 199.35 198.05 -1.3

Stop seat 1005.922 998.996 150.36 149.33 -1.03

Stop slot 608.03 614.909 121.36 122.74 1.38

milling barrel 593.19 605.091 120.32 122.74 2.42

pre drilling 538.521 547.068 122.67 124.62 1.95

Average increased output = (1.38 + 3.42) / 2 = 1.9 units

After improvement, it was shown that eliminating the idle time due

to leaving the workstation and deducting 30 minutes from the effective

production time can increase an average output of 1.9 units. This will

determine the final increase in output of the whole production line since it

is the average output of the bottleneck processes stop slot and milling

barrel.

The second alternative (B) is to reschedule a 15-minute break in

the morning at 9:00 AM to 9:15 AM. The schedule of break time before

was 15- minutes in the morning and 15 minutes in the afternoon but now,

the schedule turned to 30 minutes in the afternoon. Strictly scheduling 15-

15-minutes break shall also be implemented with monitoring. In the

policy, the operators would not be allowed to go outside the workstation

during working hour since 15 minutes will be schedule for break in the

morning and afternoon. Operators who will violate the rule shall be

subjected to disciplinary actions. The supervisor should oversee the

operators during working hours to monitor the performance of the

operators. Since there is no established policy on leaving workstation, the

47

study proposes the Human Resource department to conduct community

works such as tree planting or outreach programs and involve the

operators who will violate the policy. The community work is just a

proposal which may prevent the operators from disobeying the rules. The

decision is still in the management to determine how they are going to

discipline violating operators.

The machine unproductive time caused by operator delay of

leaving the workstation that will be eliminated when this solution is

implemented is shown in Table 4-12.

Table 4-12 Effect on the process output of rescheduling 15-minute break

Process Machine Unproduc-tive Time

Effective time (min)

Unit Normal Time (min)

Effective Capacity per

day(unit)

Increase in output /day (unit)

Face-off 26.16 200.89 0.99 202 26.42

Drilling 18.38 689.48 5.4 127 3.4

Mill ref 27.74 226.44 1.48 152 18.74

Mill clearance

18.47 1049.1 5.17 202 3.57

Stop seat 17.64 1023.6 6.69 152 2.64

Stop slot 22 630.03 5.01 125 4.39

milling barrel

26.78 619.97 4.93 125 5.43

pre drilling 22 560.52 4.39 127 5.01

The effect of the solution is that all machine unproductive time due

to operator delay of leaving workstation would be reduced without having

reduction in the total effective time of the production, thus the capacity

after improvement will be equal to the effective capacity.

Since the capacity is dictated by the bottleneck processes stop

slot and milling barrel, the increase in output would be based from the

machine unproductive time that will be eliminated in these processes.

48

The equivalent output of the machine unproductive time due to operator

delay of leaving the workstation to drink or go to the comfort room is

computed as:

For stop slot: 22 minutes / 5.01 = 4.39 units per day

For milling barrel: 26.78 / 4.93 = 5.43 units per day

Getting the average of the two values, the average increase in

output is equal to 4.91 units per day.

The management can also choose to maintain the current system

as the third alternative (C). This alternative will not reduce the effective

time of the production but will not solve the machine unproductive time

caused by operator delay of leaving the workstation.

Alternative Solutions to Experimental Factor E2

The first alternative solution to late filing is to buy table of the

designed height for the operators to be comfortable in filing the materials.

According to Niebel, the height of the table should be based on

elbow height because if the work surface is too high, the upper arms will

experience shoulder fatigue, and if low, the back is flexed to lean forward

leading to back fatigue. The effect of it on the performance of the

operators is the tendency of filing the materials just when the machine

needs the materials and have incorrect results on inspections. To design

the new height of the table, designing for the average method was

applied. This study considered the Filipino anthropometric measures as

reference to height design of the tables (see appendix J). The average

height of the operators considered is 5’6 ft or 167.64 cm. The following

values were considered in the design:

Standing Height (cm)

@5th percentile: 157

@95th percentile: 178

49

Through interpolation, the percentile where 167.64 lies, is

determined to be in the 50.6th percentile.

Elbow Height (cm)

@5th percentile: 96.5

@95th percentile: 112.8

Assuming 50th percentile, the elbow height is computed through

interpolation and this is equal to 104.65 cm. Thus, this height will be the

recommended designed height of the table. Figure 4-7shows the sample

height-designed table.

Figure 4-7. Height-designed table for filing

This action would incur the production an initial cost of Php5000

(see appendix K for estimated price). The machine unproductive time that

will be eliminated would be equal to the machine unproductive time at the

stop slot and milling barrel process less the average machine

unproductive time in other processes since these are the two processes

affected by late filing due to low-height of the table. For stop slot process,

the machine unproductive time that would be eliminated is 16.5 minutes

and 12.71 minutes for milling barrel. These values were obtained by

104.65 cm

91.44 cm

50

subtracting the average of the machine unproductive time (4.92 min) in

processes other than stop slot and milling barrel from the total machine

unproductive time at the two latter processes. This was briefly explained

in the discussion of Controllable Factor 3.

To get the effective capacity of the process after improvement, the

machine unproductive time that was eliminated would be reduced from

the average machine unproductive time in that process. In this case,

since all the recorded machine unproductive time were eliminated, there

would be no more machine unproductive time caused by late filing thus

the effective time would not be reduced.

For stop slot:

Effective time = 630.03 minutes per day

Eliminated machine UT = 16.5 minutes

New effective time = 630.03 - 0*

Capacity after improvement = 630.03 / 5.01 min

= 125.75 units per day

The same method was applied to milling barrel process. The

number of units that would be increased is equal to the average of the

increase of the stop slot and milling barrel. This is because after

improvement the capacities of the two processes are the same. Table 4-

13 shows the effect of designing table height on output of the two

processes.

Table 4-13 Effect on process output of using height-designed table for filing

Process Machine UT

(min/day)

Effective time per day (min)

Unit Normal Time (min)

Capacity per day (unit)

Increase in output per day (unit) after before

Stop slot

16.5 630.03 5.01 125.75 122.46 3.29

Milling barrel

12.71 619.97 4.93 125.75 123.18 2.58

51

Average increase = (3.29 + 2.58) / 2

= 2.94 units per day

Alternative E is to use the same table as in the other workstations.

The cost of the table was estimated to be of the same cost as the existing

table considering the same type of wood material. Using the same table

will also reduce the same amount of machine unproductive time since the

height is fair to the operators’ height. This considers that machine

unproductive time in workstations 1 to 3 due to late filing is caused by not

following the procedures set in the production.

Alternative solution F is to maintain the current system or use the

same table used in the workstation. The production would not have cost

on it but the machine unproductive time due to low-height table will be

remained in the system.

Alternative Solutions to Experimental Factor E3

Alternative solution G is to buy table of the same designed height

for inspection. Since the inspection makes use of height gage the height

of the table would still be suitable for the operator doing the inspection.

The initial cost for buying the table is also Php5000. The unproductive

times that will be reduced will be on the five last processes since these

are the processes where incorrect inspections occur due to back-fatigue.

Using the table would not surely eliminate all the unproductive time

caused by it, so the efficiency of the production would be used as the

percentage that could possibly be reduced. The current efficiency of the

production is 76% (see appendix B)

The increase in units per process was computed by deducting the

remaining machine unproductive time from the effective time of the

process and dividing the answer by the processing time.

52

For mill clearance:

Ave. machine UT = 12.82

Reduced UT = 0.76 * 12.82

= 9.74 minutes/day

Remaining UT = 12.82 - 9.74

= 3.08 minutes /day

Capacity after improvement

= (effective time - remaining UT) / processing time

= (1049.107 min - 3.08) / 5.17

= 202. 326 units / day

Increase in output = capacity after improvement - capacity before

improvement

= 212.326- 200.94 units

= 1.88 units / day

Applying the same method to other processes, the results are

shown in table 4-13 shows the reduced machine unproductive time in

these processes.

Table 4-13 Effect on process output of designing table height for inspection

Process

Ave Machine UT /day (min)

Remaining Machine UT / day (min)

Reduced machine UT / day (min)

Capacity (unit/day) Increase

in output /day (units) after before

Mill clearance 12.82 3.08 9.74 202.33 200.94 1.88

Stop seat 8.58 2.06 6.52 152.7 151.97 0.97

Stop slot 19.55 4.69 14.86 124.82 122.63 2.97

Milling barrel 11.56 2.77 8.79 125.13 123.88 1.78 Pre drilling 10.14 2.43 7.71 127.13 125.83 1.76

The bottleneck processes is the stop slot process therefore this

would dictate the increase in output of the whole line. The increase in

output would be equal to 2.97 units per day.

53

On the other hand, the management can choose alternative H

which is to maintain the current system. This would not incur cost to the

production but would not reduce the machine unproductive time caused

by low-table height for inspection.

Alternative Solutions to Experimental Factor E4

Alternative solution I is to adapt 5S program in the production.

A Five S (5S) program is usually a part of, and the key component

of establishing a Visual Workplace. It focuses on having visual order,

organization, cleanliness and standardization. It can also reduced set-up

times and cycle times, Increased floor space and working space, lower

safety incident or accident rate, better equipment reliability, and less

wasted labor.

The study recommends the company to implement the 5S

program in the production to maintain orderliness, organization, and

standards in the production line. Since the operators do not already have a

background on 5S, the management can organize a half-day orientation

about the program. Since the only 10 workers from the production will be

involved, a half-day-orientation would be enough. Table 4-14 lists the

proposed introductory discussion about each ‘S’ in the 5S.

54

Table 4-14 Proposed discussion for the orientation on 5S program

5S English Translation

Concept

Seiri

Sort

Clearing the work area: Difining all the materials that will be necessary in the production and those that are not should be kept in storage. Thework area should only have the items needed to perform the work

Seiton

Set In Order

Designating locations: Everything in the work area should be placed and designated properly. The use of signs and labels to identify "what is to be stored where" helps employees use storage locations as they were intended to be used.

Seiso

Shine

Cleanliness & workplace appearance: The work area should be clear and clean. It involves housekeeping efforts, improving the appearance of the work area, and preventive work area from getting dirty. Using preventive measures to keep the workplace clean:

• Once the work area, tools, and equipment are clean, they need to be kept that way.

• Continued housekeeping

• Preventive measures from getting dirty in the first place.

• Root cause analysis, mistake-proofing

Shit-suke

Standar-dize

Everyone doing things the same way:

Everyone in the work area and in the organization must be involved in the 5S effort, creating best practices and then getting everyone to "copy" those best practices the same way, everywhere, and every time.

Sei-ketsu

Sustain

Sustain: Ingraining the 5S's into the cultureIt involves a culture change and to achieve a culture change, it has to be established in the organization - by everyone at all levels in the organization.

Adapting 5S in the production system will minimize unproductive

times on the machining line. It can address the system’s problem on

55

machine waiting time due to double filing, not following procedures such as

prioritizing other tasks than attending the machine, material unavailability at

the workstations and other incorrect practices in the production.

Since the concept is not practiced and applied in the company,

there should be an orientation of the 5S concept to the operators in the

black slide line as well as to other operators in the whole machining

production line. Listed in table 4-15 are the proposed applications for each

‘S’ in the 5S.

Table 4-15 List of applications for each ‘S’ 5S Application

Seiri

• Define the materials frequently needed (file hand tool, unloading/loading tool, raw materials, inspection tools, and calculator, dolleys).

• Define the materials rarely used (water containers, tool changing materials, wrench, tool cutters, cleaning materials etc.)

Seiton

• Use separate boxes as containers of filed materials and materials that are to be filed.

• Label the boxes as “filed “and “to be filed”.

• Put the tools in their proper places. The file hand tool as frequently used should be placed at the right side of the table and the unloading tool at the hanging platform in front of the machine body. Only the file hand tool and the boxes should be placed in the table for ease of getting materials and filing.

• Only measuring tools(height gage, calculator, caliper) should be found in the inspection table

• Calipers used for in section in the work table should be placed in the platform of the machine.

56

Seiso

• Clean table after filing the materials. The operator assigned to the workstation should be the one responsible in cleaning his workstation. Not only the worktable should be cleaned, the but also the materials and the machine. Conduct routine cleaning maintenance. Collect wastes.

Seiketsu

• Define tasks of operators, regulations, and standard working procedures within the production. Tasks include moving the material to the next when already processed, following standard operating procedures. Machines should be attended first before other tasks. Rules include avoiding frequent leaving from work, chatting or hopping stations for no valid reason or non-work related matters.

• Use posters to remind the right procedures that will serve as a guide for the operators..

Shitsuke

• Recognize jobs that were done well d

• Bulid a concept of teamwork with the operators to motivate them

• Continuously stress and remind roles and responsibilities

This program mainly addresses the problem on double filing of the

materials. Seiton or to “set in orde” as highlighted in the table above is the

‘S’ that answers the problem on double filing which is one of the causes

that the study solves. The study recommends through the concept of

“Seiton” to use separate boxes for filed materials and materials that are yet

to be filed to prevent adhesion of waste metal chips to the slides. Figure 4-8

shows the proposed arrangement of materials used in work surface of the

table used by the operators.

57

Figure 4-8 Work table surface layout

To implement the program, the management should be able to

communicate the significance of the program to the company and to the

operators as well. They should keep reinforcing and emphasizing the

program to the operators. The proposed flow chart of implementing 5S is

shown in figure 4-9.

Figure 4-9. Flow chart of 5S program implementation

The implementation must start with the top management to build the

leadership team. They will be the ones to develop and plan the programs

that are to be taught to the operators and other employees of the company.

The next process will be communicating the planned program to the

production line operators. Included in this step is the use of communication

media such as having regular meetings involving all employees of the

company. Posters containing the important details of the program will be

helpful in reminding the operators as well as other employees of the

contents and major points of the program.

TO BE FILED

F

I

L

E

Build the Leader- ship

Communi-cate to the Body

Training and

Practice

Recognize changes

Continuous Evaluation

58

After the program has been communicated, training of the operators

and leaving them to practice will follow. Supervisors must assist and guide

the operators while practicing the details of the program to motivate them

more. The operators may be also be trained problem-solving techniques,

what to do in a certain situation, when to do a task, and how to do it. As part

of initial evaluation, the operators should be involved in recognizing

changes. The management should get inputs or ideas from the operators to

improve the program. From initial evaluation, new and improved plans can

be developed including the right sequence of processes, working

procedures and performance measures.

The cost that will be incurred in implementing 5Sprogram would

estimate to Php1500 for miscellaneous and for posters and leaflets.

The main effect on the problem of adapting 5S program is on the

elimination of machine unproductive time due to double filing of the

materials. Table 4-16 shows the machine unproductive time that would be

reduce at each process due to double filing.

Table 4-16 Machine unproductive time due to double filing

Process Machine Unproductive Time per

day (min)

Face-off 7.55

Drilling 16.76

Mill ref 7.85

Mill clearance 8.86

Stop seat 6.54

Stop slot 13.99

milling barrel 10.38

pre drilling 15.27

Table 4-17 shows the effect on the output of each process when 5S program is adapted in the production.

59

Table 4-17 Effect on process output of adapting 5S process

T

h

e

f

i

n

a

l

Before improvement, the capacity is lower due to unproductive

time, but after unproductive time reduction, the capacity was increased.

The increase in output of the whole line depends on the stop slot and

milling barrel processes since these processes are the bottleneck

processes. The increase in output would be equal to the average of the

increase in units in the two processes because the capacity results after

improvement of both processes are the same. The average output would

be equal to 2.44 units per day when the machine unproductive time due

to double filing was eliminated.

4.2.6. Evaluation of Alternative Solutions

The alternative solutions for each factor were evaluated based on

different criteria and ranking system.

For experimental factor E1, the criteria with the corresponding

percentages and the ranking system are shown in table 4-18.

Process Machine UT

(min/day)

Effective time/day (min)

Unit Normal Time (min)

Capacity Increase in units per day before after

Facing -off

7.55 200.89 0.99 195.3 202.92 7.63

Drilling 16.76 689.48 5.4 124.58 127.68 3.1

Milling Ref

7.85 226.44 1.48 147.7 153 5.3

Milling Clearance

8.86 1049.11 5.17 201.21 202.92 1.71

Stop seat 6.54 1023.56 6.69 152.02 153 0.98

Stop slot 13.99 630.03 5.01 122.96 125.75 2.79

Milling Barrel

10.38 619.97 4.93 123.65 125.76 2.11

Pre drilling

15.27 560.521 4.39 124.20 127.68 3.48

60

Table 4-18 Criteria and scoring system for factor E1

Score

Effectiveness

(50%)

(addition in units)

Fatigue-

reducing (40%)

Ease of

implementation

(10%)

3 >3- 4.5 More reducing easy

2 >1.5- 3 Slightly reducing average

1 0-1.5 Not reducing difficult

Three criteria were considered in the evaluation: effectiveness,

fatigue-reduction, and ease of implementation. Effectiveness refers to the

number of units the alternative can increase or add to the output. Fatigue-

reduction refers to the level of reduction of fatigue the alternative can

cause to the operator and ease of implementation is how easy it is for the

management to apply the solution. The summary of scores for each

alternative in each criterion is presented in table 4-19.

Table 4-19. Scores under each criterion for factor E1.

Alternatives

Effectiveness

(50%) Fatigue-

reducing

(40%)

Ease of

Implementa-

tion (10%) Units

added score

1. Add 30 minutes to

break 1.9 2 3 1

2. Reschedule 15-min

break 4.91 3 2 1

3. Maintain current

system 0 1 1 3

The summary of total final scores of each alternative is presented

in table 4-20.

61

Table 4-20. Summary of total score for factor E1

Alternatives

Effectiveness

(50%)

(addition in

units)

Fatigue-

reducing

(40%)

Ease of

implementa-

tion (10%)

Total

1. Add 30 minutes to

break 1 1.2 0.1 2.3

2. Reschedule 15-15-

min break 1.5 0.8 0.1 2.4

3. Maintain current

system 0.5 .4 0.3 1.2

Based on the total scores, the best alternative solution is to re

reschedule 15-minuute break in the morning and in the afternoon with a

total score of 2.4. Though it is less fatigue-reducing than adding 30-

minute break time, it was given the highest score because it is the most

effective solution among the three. It can render an increase in output of

4.91 units per day compared to adding 30 minutes which can only render

an increase of 1.9 units per day (computation shown in the discussion of

alternative solutions). Maintaining current system was given the lowest

score since it would not eliminate or reduce machine unproductive time

due to operator delay nor would it reduce worker-fatigue.

For experimental factors E2 and E3, same criteria and scoring

system were used. Table 4-21 shows the scoring system and the criteria

used in rating the alternatives.

Table 4-21 Criteria and scoring system for Factor E2 and E3 Score Effectiveness (40%)

(addition in units)

Cost (20%) Fatigue-reducing

(40)

3 >2-3 0- 1000 More reducing

2 >1 - 2 >1000 - 2000 Slightly reducing

1 0-1 >2000 - 3000 Not reducing

62

The summary of scores for each alternative for factor E2 under

each criterion is shown in table 4-22.

Table 4-22 Scores under each criterion for factor E2

h The total score for each alternative solution for factor E2 is

presented in table 4-23.

Table 4-23 Summary of total score for factor E2 Alternatives Effective-

ness (40%)

Cost (20%)

Fatigue-reducing (40%)

Total

1. Buy height-designed

table

1.2 0.2 1.2 2.6

2. Use table used in other

workstations

1.2 0.2 0.8 2.2

3. Maintain current system 0.4 0.6 0.4 1.4

Based on the final scores, buying height-designed table is the best

solution to reduce machine unproductive time caused by late filing with a

total score of 2.6. It is as effective as the second alternative solution

because both can render an increase of 2.94 units per day. Buying either

table would also incur the same cost. But the first alternative is more

fatigue-reducing since the height of the table is designed based on the

height of the operator that is why it is given the highest score. Though

Alternatives

Effectiveness (40%)

Cost (20%) Fatigue-reducing (40%) Units

added score

Cost (Php)

score

1. Buy height-designed

table 2.94 3 3000 1 3

2. Use table used in other

workstations 2.94 3 3000 1 2

3. Maintain current system 0 1 0 3 1

63

maintaining the current system would not incur any cost, it was given the

lowest score because it is the not fatigue-reducing and it is ineffective.

For evaluation of Experimental Factor E3, the same criteria and

scoring system as in factor E3 were used. Table 4-24 shows the score for

each alternative under each criterion.

Table 4-24 Score under each criterion for factor E3

T

The summary of total scores for each alternative solution for

factor E3 is presented in table 4-25.

Table 4-25 Summary of total score for factor E3.

Based on the total scores, the best solution to reducing machine

unproductive time due to machine adjustment is buying height- designed

table with a total score of 2.6. It was given the highest score because it is

Alternatives

Effectiveness (40%)

Cost (20%) Fatigue-reducing (40 %)

Units

added

score Cost

(Php)

score

1. Buy height-designed

table for inspection

2.97

3 3000 1 3

2. Maintain current

system

0

1 0 3 1

Alternatives Effectiveness

(40%) Cost (20%)

Fatigue-reducing (40%)

Total

1. Buy height-

designed table for

inspection

1.2 0.2 1.2 2.6

2. Maintain current

system 0.4 0.6 0.4 1.4

64

more effective than maintaining the current system though it would incur

cost to the production. It can render an increase of 2.97 units per day.

Also, it is fatigue-reducing since the height of the table is designed based

on the height of the operator.

For evaluation of factor E4, the criteria that were considered

include cost of implementation, ease of implementation and effectiveness.

Table 4-26 presents the scoring system for each alternative.

Table 4-26 Criteria and Scoring system for factor E4

The total scores for each alternative for factor E4 are presented in

Table 4-27

Table 4-27 Scores under each criterion for factor E4 Alternative Effectiveness

(50%)

Cost (30%)

Ease of

implementation

(20%) Added

units

score Cost

(Php)

score

1. Adapt 5S

Program 2.44 3 1500 2 2

2. Maintain

current system 0 1 0 3 3

Table 4-28 summarizes the total score of each alternative for

factor E4.

Score Effectiveness (50%) (addition in units)

Cost (30%) (Php)

Ease of implementation

(20%) 3 >2-3 0- 1000 easy

2 >1 - 2 >1000 - 2000 average

1 0-1 >2000 - 3000 difficult

65

Table 4-28 Summary of total score for factor E4

Adapting 5S program is the solution to reducing machine

unproductive time due to double filing of the materials. Although it would

incur cost to the company and the company has to plan for its

implementation it is better than maintaining the current system since it

can render an increase of 2.44 units per day compared to maintaining the

current system which is ineffective because it would not reduce or

eliminate the machine unproductive time caused by double filing.

The summary of reduced machine unproductive time is at each

cause is presented in Table 4-29 along with the overall increase per day

at each process. Capacities of each process per day before and after

improvement are also presented to see the increase per day from

reducing machine unproductive time at each process.

Alternatives

Effectiveness (50%)

(addition in units)

Cost (30%)

Ease of implementation

(20%)

Total

1. Adapt 5S

Program 1.5 0.6 0.4 2.5

2. Maintain

current system 0.5 0.9 0.6 2

66

Table 4-29. Summary of increased output per day at each process

67

As shown in the table above, implementing the best solutions would

reduce a total of 68.83 minutes of machine unproductive time. It is also shown

that these, in effect would increase the output of the black slide machining

production line by 14 units per day or 364 units per month. This is equivalent

to Php1, 218, 672 per year but to meet the monthly demand of 2800 units per

month, only 329 units are considered lost sales thus this number of units will be

added to the sales of the production. This is equivalent to Php1, 101, 492 per

year. The summary of costs for the initial year of implementing each solution is

presented in Table 4-30.

Table 4-30. Summary of costs of implementing the solutions

The savings for the initial year would be equal to the difference of the

total benefits and the total cost incurred in the first year.

Savings for the initial year = Php1, 101, 492 – Php12, 250

= Php1, 089, 242

For the succeeding years, no more costs will be incurred since the

recommendations require one-time investments. The savings for the

succeeding then would then be equal to the annual benefit of Php1, 101, 492.

Recommendation Costs for the Initial Year

(Php)

Buy height-designed table for filing

and inspection 5000 *2

Adapt 5S 1500

Buy tools 750

Total 12, 250

68

5. Summary and Conclusions

69

The Black slide machining production line does not meet its monthly

demand of 2800 units. Because of this, the production line loses sales of 329

units each month amounting to Php1, 101, 492 per year. Using time study, it was

found out that the capacity if the line can meet the demand. One possible area

identified for increasing output was the reduction of machine unproductive time to

increase the monthly output of the production line. It was verified that the 22% of

the total effective production time is accounted by machine unproductive time.

Using Ishikawa diagram, the root causes were identified. These include

low height design of table for filing and inspection, insufficient number of tools,

lack of strict supervision, poor workplace, and worker delay which include

chatting of operators, start-up delay and frequent leaving of the workstation. CNX

Analysis was used to group the factors and to determine where to focus the

solutions and recommendations. Chatting of operators was identified as noise.

Start-up delay, insufficient number of tools, and lack of strict supervision were

grouped under controllable factors. Frequent delay of leaving the workstation,

low height design of tables, and poor workplace were categorized under

experimental factors. Direct solutions were addressed to controllable factors and

alternative solutions were generated for the experimental factors.

For frequent delay of leaving the workstation the alternative solutions

generated were adding 30-minute break time, rescheduling 15-min break time in

the morning and maintaining the current system. For low height design of table

for filing, the alternative solutions include buying new height-designed table,

providing the same table used in other workstations, and keeping the current

system. For low-height table used in inspection, the alternatives generated were

buying the height-designed table and maintaining the current system. For poor

workplace, the alternatives include adapting 5S program and maintaining the

current system. Using different criteria for each factor and through factor rating

method, the alternatives were evaluated. Some of the criteria used are

effectiveness, cost of implementation and fatigue reduction.

From the ratings, the best alternative solutions determined include

rescheduling break time, adaptation of 5S program, and the use of height-

designed tables for inspection and for filing.

70

Based on the results, it was concluded that a monthly increase of 364

units on the bottleneck process can be improved and from these the production

can now meet its monthly demand of 2800 units per month. The costs of each

solution chosen were also considered and it was determined that if the

recommendations would be implemented, the company would have a total

savings of Php1, 089, 242 in the first year and Php1, 101, 492 for the succeeding

years.

71

6. Recommendations

72

The study has come up with four major recommendations. First is

rescheduling 15-minute break of operators in the morning and 15 minutes in the

afternoon. Since worker delay is the main cause of machine unproductive time in

the production this would reduce such unproductive time.

Second is the use of height-designed tables to prevent worker back

fatigue. This would reduce delays due to fatigue and so the unproductive time of

the machines due to machine adjustments. Along with these two

recommendations is having strict supervision in the production. The operators

should always be supervised to monitor if they are performing the assigned tasks

to them. This is to address avoidable worker delays such as chatting with other

operators in the machining section and station hopping.

Third, there should be tools designated for each workstation to avoid

transport delays of operators. It should also be taught to the operators to keep

their own tools to avoid misplacement and tool searching.

Fourth, the study recommends adapting and implementing 5S program in

the production. As one main cause of idle time is the practice of double filing of

the materials due to dirty workplace, adapting 5S will lessen such problem. The

program would also address problems on materials unavailability and problems

on regarding procedures. In line with the program is building standards and

correct working procedures for the operators to follow. The management should

train the operators on proper working procedures such as cleaning the

workplace, keeping of tools, following standard operating procedures, and doing

their own responsibilities.

The management should also be able to build and impart a concept of

discipline to the operators so that the procedures set would not be violated and

avoidable delays would be prevented in the production. The management should

also continuously monitor and evaluate the performance of the operators.

73

7. Areas for Further Study

74

The study considered only the reduction of the machine unproductive

time as an area for improvement and a means to meeting demand by increasing

the output of the Black slide machining production line.

Studies can also be conducted on other possible area which causes low

production output. The material supply or delivery, and the performance of the

operators working in the night shift can also have effect on the output of the black

slide production line. The gathering of data was done in the morning shift only.

Twenty two percent was verified as the percentage of machine unproductive time

contributed by the morning shift which reduces the potential output of the

production line. This only reflects the unproductive time present in the morning

shift and so the night shift can also be studied to get the percentage of

unproductive time it contributes to the total unproductive time per day in the

production line.

Four machines only which are regularly used were considered in the

study. The other machine that is not regularly used can also be studied in order

to evaluate its effect in the capacity of the production. Utilizing this machine may

increase the effective capacity of the black slide production line and so the output

of the line can also be increased.

A study can also be done on increasing the cycle time of the machines to

speed up processing but this will involve a trade-off between increasing

production rate and increasing possible machine delays because the number of

operators might not be enough to handle the machines.