MIT 3710 - Methods Engineering Course

8/3/2019 MIT 3710 - Methods Engineering Course

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MIT 3710

Methods Design

Welcome to the methods design course!



INTRODUCTION

Instructor

Course

Syllabus

Grading

Text



METHODS ENGINEERNING

Definition

“the systematic procedure for subjecting all direct and

indirect operations to close scrutiny in order to introduceimprovements that will make work easier to perform andwill allow work to be done in less time and with lessinvestment per unit”1 without an adverse effect upon quality

“Thus, the real objective of methods engineering is profitimprovement”1 through lowering unit cost by continuousImprovement of manufacturing processes.



METHODS ENGINEERNING

Methods Engineering is simply a discipline of using

systematic analyses of processes, both proposed

and existing, in order to eliminate waste (“muda”).

Therefore, the tools and techniques of methods

engineering are very useful in achieving the goals

of lean manufacturing.



METHODS ENGINEERING

With the detailed analysis of any job, you will find

waste. That can, almost, be guaranteed. The

causes and necessary corrective measures for the

waste will vary, making some corrective actioneasier than others (“low hanging fruit”).

Total work content Ineffective time

Total time content of an operation under current conditions

Minimum job content Process inefficiency issues shortcomings



METHODS ENGINEERING

Some Typical Methods Engineering Functions

Design and develop processes

Design and develop tooling and fixtures Optimize operator and machine relationships Continuous improvement of workstation layouts Developing and maintaining work standards

The result of these efforts will be more efficient production bymaking work easier to perform, less time consuming, and lesscostly per unit produced.



HISTORY

Frederick Winslow Taylor (1856 – 1915)2

“Father of Scientific Management” or modern time study

Began time study in 1881 at Midvale Steel Co.3

Presented findings in 1895 to ASME3

“Shop Management” presented to ASME in 19033

Scientific Management approach to work (see p. 28)

Innovations (see page 28 of text)

Early controversy with “efficiency experts”5



HISTORY Are Taylor’s Principles Out of Date?

Read about Dr. Shigeo Shingo (page 33 of text)

and excerpts from The Visual Factory, by

Michel Greif, pages 61 through 66.

The techniques are still useful, today, and can

be key in implementing lean manufacturing byassisting in eliminating waste.



History

Frank (1868-1924) and Lillian (1878-1972) Gilbreth4

Parents of motion study

Frank founded motion study around 1900 They developed many new techniques to study work

Elimination of wasted motion = “Work Simplification”

Developed 17 basic manual motions, “Therbligs”



HISTORY

For some twenty years or so (ca. 1910 until 1930)

there were two groups conducting work study.

One group followed Taylor’s scientific

management approach and the other followed

the motion study techniques of the Gilbreths.

Finally, it was realized that the efforts of the twoshould be combined, and this led to what is

known by some as “methods engineering”.



LEAN MANUFACTURING

Chapter two of the text has a nice, brief discussion about

“lean” in the manufacturing context. At the center of this

discussion is Dr. Shigeo Shingo, a world renowned

Japanese industrial engineer.

Dr. Shingo was a follower of Fred Taylor’s analytical

philosophy and Frank Gilbreth’s exhaustive pursuit of goals

and the single best method of doing a job.6



LEAN MANUFACTURING

“The philosophy of Shigeo Shingo and its

application to motion and time study tools is the

basis for the lean environment approach.”7

The “lean production environment” focuses upon

the elimination of all forms of waste in

manufacturing. The term was coined by JamesWomack and is used to differentiate the practices

of Toyota from those of mass production.7



LEAN MANUFACTURING

Lean involves an environment that will utilize the

efforts of the entire workforce to achieve the

elimination of waste (“muda”). This means that

anyone may use tools available through motion

and time study, quality and process control, or any

other traditional mass production system

functional area that may be helpful in achieving

lean manufacturing.8



LEAN MANUFACTURING

Dr. Shingo attributes Toyota’s tremendous

improvements over their bleak situation in the1960s to the application of traditional motion and

time study problem-solving techniques, applied asneeded to obvious bottlenecks.9

The text presents Womack and Jones’ five-year

time frame for developing a lean organization, butthis is beyond the scope of this course. We willfocus upon motion and time study techniques.



LEAN MANUFACTURING

Dr. Shingo pointed out the importance of analyses

of processes and operations, and motion and time

study techniques are designed for these

purposes.10

Process: a continuous flow by which raw materials are

converted to finished goods11

Operation: any action performed by man, machine, or

equipment on raw materials or intermediate or finished

products11



MOTION & TIME STUDY Motion Study

As has been implied, motion and time study are

two different subjects, each with its own set of

tools or techniques.

Motion studies were conducted by the Gilbreths in

search of the “one best way” of doing a task.

These studies seek to eliminate wasted motion

and specify the proper way of completing a task.They were not concerned with cycle time, since

the proper method will have minimal cycle time.12




The first step in process or operation improvement

should begin with motion study. It is with motion

study that you will, often, find the largest savings

opportunities.13

There are two sets of motion study tools. They are

referred to as:1. Macromotion: factory or process flow

2. Micromotion: operation or job




Macromotion studies should be conducted prior to

micromotion studies for three reasons:

1. Macro savings are usually greater2. Macro may eliminate or change operations

3. Starting with micro could waste your time!

Of course there are appropriate times to conductmicromotion studies of operations without macro

studies, first.




Improvement Actions14

(in priority sequence)

1. Eliminate if possible

2. Combine with another activity

3. Change or rearrange the sequence4. Simplify the activity as much as possible



MOTION & TIME STUDY Time Study

Time study is a work measurement technique used

for the setting of a time standard. The text’s

author provides a definition of “time standard” as

follows:

“the time required to produce a product at a work

station with the following three conditions:

(1) a qualified, well-trained operator,(2) working at a normal pace, and

(3) doing a specific task”15




Definitions (ANSI)

Time study: is a work measurement technique consistingof a careful time measurement of a task with a time

measuring instrument, with appropriate adjustments for

work pace, unavoidable delays, and personal needs. It is

used to determine the time required by a qualified and

trained person working at normal pace to do a task




Definitions (ANSI)

Qualified operator: A worker who, by virtue of his/her

training, skill, and experience, is able to perform a task

within acceptable quality and time limits.

Normal pace: the manual pace required to produce an

acceptable amount of work by a qualified operator followinga prescribed method under standard conditions with an

effort that does not incur cumulative fatigue from day to day(considered 100% and often referred to as “100% pace”)




Proper procedure is to always conduct

motion study (or methods study)prior

to conducting the time study!

Why do you think this is true?



MOTION & TIME STUDY Work Measurement

Definition (ANSI)

Work measurement: is a generic term used to refer to thesetting of a time standard by a recognized industrial

engineering technique

What are these “recognized industrial engineering techniques”?

(Also referred to as work measurement techniques.)




Work Measurement Techniques16

1. Time study

2. Standard data3. PTS (pre-determined time systems)

4. Work sampling (ratio-delay studies)

There are two other techniques for setting time standards,but they are not work measurement techniques. They are

historical data and estimates. We will discuss these, later.




Time Study

The most commonly used technique

Uses a time measurement instrument Follows a specific procedure: (after proper method determined)

Job is broken into elements

Each element is timed

Performance rating is necessary Allowances must be added

Standard time is calculated




Standard Data

Time formulas used to calculate standard times

Linear regression graphs used to depict rates/times Requires much time, effort, and documentation

Most cost effective way of setting time standards

Most consistent method of setting time standards




Pre-Determined Time Systems (PTS)

Developed through research, including film analysis

Body motions are broken into basic elements Forces methods analysis (motion study)

Can set standards prior to actual production




Work Sampling18

Based upon the laws of probability

Random samples (observations) Samples taken have the same pattern as population

Also referred to as “ratio-delay studies”




Not Work Measurement Techniques

Historical Data

Standards based upon similar jobs previously produced19 Uses actual clock hours on similar work

Builds in inefficiencies of previous work

Estimates Based upon “expert” opinion (often the supervisor)

Commonly used prior to time study

Lacks in accuracy (avg. deviation from actual time = 25%)19



MOTION & TIME STUDY Importance and Uses of Time Study

Time standards provide goals for production. It has been

estimated that organizations that operate without time

standards only achieve about 60% performance. With time

standards, the performance improves to an average of85%, or a forty-two percent improvement!

Rules of thumb:

Plants without standards average 60%

Plants with time standards average 85%

Plants with incentive systems average 120%17



MOTION & TIME STUDY Importance and Uses of Time Study

Lets look at the material presented in the text on

pages 43 through 57.



MACROMOTION STUDY

As was mentioned earlier, the overall process flow

should be studied prior to analysis of individual

jobs, and the macromotion techniques are

designed for this purpose.20

Take a look at what the author of the text refers to

as the “Cost Reduction Formula” (p. 68). Thistable summarizes the actions of the methods

engineer when conducting a macromotion study.



MACROMOTION STUDY

In order to eliminate waste and improve your

manufacturing facility’s processes, it is important

to, first, understand the product flow through the

entire organization. Macromotion tools allow you

to develop this knowledge in a systematic way.

The simple procedure outlined in the “Cost

Reduction Formula” will lead to this knowledge.



MACROMOTION STUDY

All motion study tools have been developed to

assist in the analysis of processes or operations.

These tools may be tweaked by the analyst to fit a

particular need, so let your imagination flow andutilize the tools as they best fit your specific need.

Let’s, briefly, look through part of chapter 5 to see some of what the text’s author presents, beginning

on page 69.



MACROMOTION STUDY Flow Diagram, Fig. 5-1

Elimination of handling & travel by relocating press & receiving castings at back door.



MACROMOTION STUDY



MICROMOTION STUDY

The micromotion study tools and techniques are

designed to focus upon an individual job or activity.

As was pointed out earlier, these studies should be

completed after macromotion study.

Do you remember why?

The goal of micromotion study is to eliminate

waste on the operation level.



PRACTICEProcess Charting

We will review the process chart form (to be handed out) in

order to understand its format, then you will be given a

task, already broken into elements, to transfer to the form.

Complete these steps for this “present method”:

Fill in the header information so the details will not be lost

Write in each element and mark the appropriate symbol

Document any distances traveled

Fill in appropriate quantities

Enter task element times

Complete the “Summary” information



OPERATOR-MACHINE CHARTMicro-Motion Technique

What is it?a chart showing the exact relationship in time between the

working cycle of the person and the operating cycle of the

machine or machines21

When is it used?to analyze one work station

Why is it used?to reduce waste (lower unit cost) by identifying inefficient

utilization of the operator and/or machine’s time



OPERATOR-MACHINE CHART

How does it work?

Breaks person & machine’s work into elements

Charts the exact time for each, to scale, side by side Clearly shows idle time for each (operator and machine)

Improvement possibilities are identifiable

“Machine coupling” possibilities are evident



OPERATOR-MACHINE CHARTFig. 6-2 (current) (pp. 93 - 95 of Text) Fig. 6-3 (new)



OPERATOR-MACHINE CHARTWe will use this format.

This is an example of an alternate format for Fig. 6-3.Drawn to Scale



OPERATOR-MACHINE CHART



PRACTICEOperator-Machine Chart (page 1 of 4)

On grid paper, to be provided by the instructor, and using a

pencil, construct an operator-machine chart, given the

following information:

One operator is operating one machine

Operator loading the machine requires 0.250 minute

Operator unloading the machine requires 0.250 minute

The machine is unloaded just prior to loading

The machine’s cycle time is 0.500 minute The machine produces one unit per cycle

Leave space on the chart for adding additional machines!




After constructing the operator-machine chart, answer the

following questions:

How much idle time per cycle does the operator experience?

How much idle time per cycle is being experienced by the machine?

How many “normal” units per minute are being produced?

How many units per shift should be expected of this operation?*

* Allowances are 10% for this operation (Allowance Factor = 1.10)




Add a second, identical machine to the chart,

given the following information:

One operator is operating both machines

Operator loading requires 0.250 minute for each machine Operator unloading requires 0.250 minute for each machine

The machines are unloaded just prior to loading

The machines, each, have a cycle time of 0.500 minute

Walk time between the machines is 0.100 minute (one way)

Each machine produces one unit per cycle




After constructing the operator-machine chart with an

additional machine, answer the following questions:

How much idle time per cycle does the operator experience?

How much idle time per cycle does each machine experience?

How many “normal” units per minute are being produced?

How many units per shift should be expected of this operation?*

* Allowances are 10% for this operation (Allowance Factor = 1.10)



WORK STATION DESIGN

Chapter 7 in the text is divided into three sections:

Work Station Design Top view of workstation usually depicted

Include a layout of the entire work area

Show all materials used (raw and finished) Include all fixtures and tools needed

Principles of Motion Economy Initiated by the Gilbreths but added to over the years22

Leads to more efficient and easier jobs Motion Patterns

Depicts paths of both hands during the work cycle

Jobs are divided into “elements”



WORK STATION DESIGN

The “Principles of Motion Economy” can be broken intothree subdivisions:23

1. The use of the human body

2. The arrangement of the workplace

3. The design of tools and equipment

By the titles of the subdivisions, it is easy to see the close

relationship between motion economy and ergonomics and

human factors.

Ergonomics: “the study of the interface (or interaction) between

humans and the objects they use and the environments they function

in”24



WORK STATION DESIGN

Turn to page 111 of the text,

and we will look through the motion economypoints made by Meyers

More complete lists of principles and discussions can be found in

Barnes’ or Neibel’s books (listed in the bibliography).



TIME STUDY

Remember that time study is the most frequentlyused method of developing a time standard.25

Also, recall that a time standard is “the time

required to produce a product at a work station

with the following three conditions:

(1) a qualified, well-trained operator,

(2) working at a normal pace, and

(3) doing a specific task”15 (following the prescribed method)



TIME STUDY Tools

What tools are necessary to conduct a study?

Stopwatch (select appropriate type)

Form Clipboard

Pencil & eraser

Calculator

Tachometer (if needed for belt or shaft speeds)

Videotape recorder (if appropriate or needed)



TIME STUDY Types

There are two basic types of time study. They are:

Continuous watch runs continuously during the study

reading is noted at end of each element much clerical work required

preferred method by some – forces discipline

Snap-Back watch snapped back to zero at end of each element

less clerical work and easier to conduct

Must be disciplined to avoid neglecting delays, etc.



TIME STUDY Procedure

Let’s look through and discuss pages

172 through 184 of the text.

TIME STUDY



TIME STUDY Procedure

T ST D



TIME STUDY Number of Observations

The following is the formula I prefer, where:

N = number of observations (samples)

s = standard deviation (calculated) t = value from table

k = accuracy desired (given) = sample mean (calculated)

2

xk

st N

x

TIME STUDY



TIME STUDY Number of Observations

Given the following information from a time study, calculate the

number of observations necessary to provide 95% confidence that

our sample mean is within +/- 5% (accuracy) of the true mean for

the job element.

Element Observed Times “t”n-1 distribution table value = 2.262

0.023 minute 0.019

0.020 0.023

0.025 0.025

0.022 0.027

0.023 0.0232

xk

st N

TIME STUDY



TIME STUDY Continuous

TIME STUDY



TIME STUDY Performance Rating

Rating , leveling , and normalizing are all terms that

refer to the same process of adjusting the observed time to

perform an operation to the time that should be required,

keeping in mind the definition of standard time:

“the time required to produce a product at a work station

with the following three conditions:

(1) a qualified, well-trained operator,(2) working at a normal pace, and

(3) doing a specific task”15

TIME STUDY




More simply put: Performance rating is leveling

the actual observed time to the time it should take

to complete the task (“normal” time).

Rating performance is considered the most difficult and

debated portion of time study, and there have been a

number of attempts to remove the subjectivity of rating by

devising systems that objectively determine the rating

factor; however, simplicity has won out over the years!

TIME STUDY




Of all the more complicated systems developed, probably

the most popular was the “Westinghouse System” or “LMS

System”, named for its developers: Lowry, Maynard, and

Stegemerten. This system, published in 1927, rates fourfactors:26

1. Skill (qualified and trained - not learning the job)

2. Consistency (an indication of skill)

3. Conditions (working conditions are not often a factor)4. Effort (the most important factor - operator’s speed)27

TIME STUDY




“Speed rating” (or “performance rating”) is by far

the most widely used rating system.28 It is, also,

the simplest, since it rates only one factor, effort or

the speed/pace/tempo of the operator.

The time study analyst must have a good understanding of

normal pace for his/her industry. It is necessary to have

knowledge of the jobs studied, to include safety and qualityrequirements, tolerances of parts, and extra care demands

(highly polished surfaces, etc.)

TIME STUDY




Normal Pace Benchmarks for Effort29

Walking 264 feet in 1.000 minute (3 mph) Dealing 52 cards in 0.500 minute

30 pins into a pin-board in 0.435 min.

TIME STUDY




In order to normalize or level the observed time,

you simply apply the performance rating factor

(PRF) to the average observed time.

Observed time x PRF = normal time

The PRF is, simply, your rating of the operator’s

effort. For example, if you feel the operator isworking at 90% of normal, the PRF is 0.90. If your

rating is 110%, the PRF is 1.10.

TIME STUDY




Let’s assume we are in the process of a time study of a job

with three elements and have the following observed times

and ratings:

Elem. Avg. Observed Time Rating Normal Time

1 0.033 minute 90%

2 0.157 95%

3 0.082 105%

Calculate the normal times for each element of this job.

TIME STUDY




When do I rate the operator’s performance?

As you know, jobs are divided into elements prior to a time

study, and each element is timed. Some analysts rate the

performance of each element (53%), some rate each

observation (13%), and some rate the overall job (34%).30

However you prefer to do it, the rating must be done while

watching the operator, not at your desk, later.

Remember, performance rating is not for machine time!

TIME STUDY




Concept of Normal Performance & Human Capability32

Approximately 95% of the industrial workforce (18-65)

are capable of achieving 100% (normal) performance The average worker can achieve 120% performance

The degree of variation in workers’ capabilities is a

ratio of around 1:2

Max. human performance capability is about 160%

(Sketch normal curve on board depicting the above)

TIME STUDY




Why isn’t a process achieving 100% performance? 32

Worker(s) not following the prescribed method

Inadequate delay allowances (discuss later) Inexperienced workers (“learning curve”) – not qualified

Materials out of specification

Equipment or tooling failure (down time) – poor PMs

Incapable workers allowed to remain in workforce

TIME STUDY




Performance rating practice!

TIME STUDY



TIME STUDY Allowances

If the normal time to complete a unit of production

is 1.000 minute, how many units should be

expected at the end of an eight-hour shift?

480?

(There are 480 minutes in an eight-hour shift.)

No! Why not ??

TIME STUDY




The final step to arrive at a fair standard is to

include time for basic needs during the shift.

These basic needs fall into three categories:

1. Personal

2. Fatigue (if applied, only to the effort portion)

3. Unavoidable Delays

(These are commonly referred to as “P,F,&D” allowances.)

TIME STUDY




“The fundamental purpose of allowances is to add

enough time to the normal production time to

enable the average worker to meet the standard

when performing at a normal pace.”31

To be realistic, the accepted lost production time

during the shift must be factored into the time to do

the work to arrive at an accurate standard.

TIME STUDY



TIME STUDY Allowances - Personal

The personal allowance generally includes things like:

trips to the restroom

trips to the drinking fountain adjusting safety equipment or cleaning glasses

TIME STUDY



TIME STUDY Allowances - Fatigue

The fatigue allowance is cause for debate in many work

measurement circles. With modern workplace comforts

and conveniences, the fatigue allowance is often

unnecessary and may be considered covered by the

morning and afternoon breaks.

Fatigue allowance should not be added unless a loss of

production is experienced due to fatigue or monotony.

How do I know if production is lost due to fatigue?

TIME STUDY



TIME STUDY Allowances - Fatigue

There have been a number of methods devised in an

attempt to measure fatigue created by work. These have

included:

physical tests (work rate) chemical tests (body fluids)

physiological tests (pulse, BP, oxygen consumption)

However, the most often used method attempting tomeasure fatigue is measuring the decline of production

during the day.33

TIME STUDY



TIME STUDY Allowances - Delays

Only acceptable unavoidable delays that enhance or arenecessary for production to occur are to be considered forinclusion in allowances. If a delay is avoidable, eliminate it!You, certainly, do not want to accept lost production time

due to an avoidable issue.

Some unavoidable delay examples:

receiving set-up instructions discussing quality issues with supervisor or quality inherent equipment demands (adjustments, etc.) removing and putting on safety equipment (at breaks) clean-up time (end of shift)

TIME STUDY




How is the allowance percentage calculated? 34

Allowances are a percentage of production time, so the

correct method of determining the allowance percentage

includes removing non-productive time from the calculation.

The total percentage allowance calculation is:

Allowance = allowance min. / (shift min. – allowance min.)

Allow. Factor (AF) = shift min. / (shift min. – allow. min.)

TIME STUDY




How are allowances determined? 35

Allowances are usually determined by work

sampling. They may, also, be determined throughdelay studies (production studies), but these are

very demanding.

TIME STUDY




Given the information, below, from a study to determine

appropriate allowances for a production area, calculate the

total allowance percentage and the allowance factor (AF).

Personal time 15 minutes Fatigue time 20 minutes (breaks)

Delays: (Unavoidable)

Start-Up at beginning of shift 2 minutes

Communications with supervisor 5 minutes Remove & put on safety equip. 6 minutes

Clean up at end of shift 7 minutes

TIME STUDY




Given the time and effort put into developing an accurate

standard time, applying an arbitrary allowance factor

should be avoided. This would only destroy the accuracy.

In addition, be aware of how allowances are applicable,

since they may be applied to three different categories of

work. Every allowance time may not apply to every job.

allowances applicable to the total cycle time allowances applicable to the machine time, only

allowances applicable to the effort time, only36

STANDARD TIME



STANDARD TIME

Recall the definition of a time standard or standardtime:

“the time required to produce a product at a work

station with the following three conditions:

(1) a qualified, well-trained operator,

(2) working at a normal pace, and

(3) doing a specific task”15 (following the prescribed method)

(Standard time is sometimes referred to as “allowed time” or “standard allowed time”.)

STANDARD TIME



STANDARD TIME

We have, now, covered all the steps necessary to

determine the standard time to complete a task,

using time study. In summary, they are:

Develop the proper method (micro-motion study)

Determine the average observed time

Performance rate the operator

Calculate the normal time for the task

Apply the allowance factor

STANDARD TIME



STANDARD TIME

For the sake of simplicity, let us assume that the followingobserved times were taken for the completion of a one-

element task. Calculate the standard time for this job.

Performance rating: 90% (overall)Allowances: 15%

Observed times (minutes):

0.100 0.090 0.130 0.110 0.100

0.110 0.120 0.110 0.100 0.090

0.120 0.100 0.120 0.110 0.110

STANDARD TIME



STANDARD TIME

What would be the standard number of units expected fromthe previous operation:

per minute:

per hour: per shift:

If you went out to watch the operation, what should be the

rate of production (in units per minute)?

Have enough observations been taken (for 95%, +/- 5%)?

STANDARD TIME



STANDARD TIME

Calculate the Standard Time

(Times shown in hundredths of a minute. Standard allowance is 12%)Element C Y C L E S Normal

Description 1 2 3 4 5 6 7 8 9 10 Avg. PR Time

1. Unit to 5 6 4 5 5 6 5 7 5 5 90

Bench

2. Assemble 17 15 17 18 14 17 16 15 17 37 90

3 screws

3. Assemble 10 9 9 8 11 10 9 10 11 9 110

handle

4. Assemble 20 19 22 18 23 17 20 21 22 20 85

Brace

5. Aside to 4 5 7 5 6 5 5 7 5 7 90

conveyor

STANDARD TIME



STANDARD TIME

Calculate the Standard Time

Element C Y C L E S Normal

Description 1 2 3 4 5 6 7 8 9 10 Avg. PR Time

1. Unit to 5 6 4 5 5 6 5 7 5 5 0.0530 90 0.0477

bench

2. Assemble 17 15 17 18 14 17 16 15 17 37 0.1622 90 0.1460 3 screws

3. Assemble 10 9 9 8 11 10 9 10 11 9 0.0960 110 0.1056

handle

4. Assemble 20 19 22 18 23 17 20 21 22 20 0.2020 85 0.1717

brace

5. Aside to 4 5 7 5 6 5 5 7 5 7 0.0560 90 0.0504

conveyor

Total Task Normal Time: 0.5214

Task Standard Time: 0.584 m/u

STANDARD TIME



STANDARD TIME

Handout time study problem

-- standard time calculation practice --

times are in minutes

assume enough observations for desired accuracy

Process time for equipment is rated at 100%

Resupply and other occasional tasks are pro-rated

STANDARD DATA



STANDARD DATA Definition

Standard Data

(ANSI)

“… a structured collection of normal time values for work

elements codified in a tabular or graphic form. The datais used as a basis for determining time standards onwork similar to that from which the data was collected

without making additional studies.”

STANDARD DATA



STANDARD DATA

Levels of Standard Data

Motion = the most detailed and flexible butrequires more time to apply

Element = Data that covers an entire element ofa task. It is less flexible than motion but quickerto apply.

Task = data that covers a complete task, notflexible but very fast

STANDARD DATA



STANDARD DATA

When developing standard data, you mustdistinguish between “constant” and “variable”

portions of the task.37

constant = This portion of the job will not changesignificantly even though the part being producedchanges; therefore the time to perform this portionof the job will remain the same.

variable = time requirements change with partcharacteristics (dimensions, weight, etc.)

STANDARD DATA



Let’ s look at examples of

> motion> element

> task

standard data

STANDARD DATA



STANDARD DATA

Turn to page 213 in the text,

and we will review Meyers’ list of

advantages of standard data.

METHODS ENGINEERING



METHODS ENGINEERINGand the Product Life Cycle

Let’s look at a couple of things that may

assist in the understanding of when methods

work applies during the product life cycle.

Product Life Cycle

Continuous Improvement Cycle

LINE BALANCING



LINE BALANCING

Very often, situations are encountered whereseveral operators will be performing work as a

single production unit. Each operator has a

specific portion of the product to assemble, andafter all the operators have completed their portion

of the work, the product is completed.

These operations may be connected by means ofa conveyor or may be in close proximity so that

parts are easily passed from one to the other.

LINE BALANCING



LINE BALANCING

Purposes of Assembly Line Balancing38

Equalize workload among the assemblers

Identify the bottleneck operation

Establish the speed of the assembly line Determine number of work stations/operators

Determine labor cost

Establish workload of operators Assist in plant layout

Reduce production cost

LINE BALANCING



N N NG

Sketch assembly line examples on the board.

Identify the “line balance” operation

Calculate the standard time per unit

Determine the normal time production rate

Stress the importance of balancing work

Discuss the significance of the “bottleneck”

Calculate “percent line balance”

LINE BALANCING



Given the information, below, for an assembly line, answer or calculate the

requested information:

Seven operations & operators: (the standard minutes include 12% allowance)1. 0.372 std. min.

2. 0.237

3. 0.389

4. 0.2735. 0.279

6. 0.155

7. 0.333

Identify the “bottleneck” or “line balance” operation

Calculate the standard time (in minutes) per unit How many units per 8-hour shift are expected?

At what production rate (units per minute) should this line be running?

LINE BALANCING



LINE BALANCING



Some Thoughts for Improving Output

Assign a portion of the line balance operation’s

work to another station

Improve the method of the line balance station(may or may not require capital investment)

Utilize an additional operator at the line balancestation, full or part-time

Work bottleneck operation overtime in order toaccumulate units from which to supplement

PERFORMANCE



In order to assist in maintaining proper efficiencyand performance, production data are collected

and measurements made of actual results versus

expectations. One of the measures used isperformance against standard.

100% X ActualTime

EarnedTimeePerformanc

PERFORMANCE



Recall this problem worked earlier. Performance against standard, based upon

a given amount of production, has been added to the calculations, below.

Seven operations & operators: (the standard minutes include 12% allowance)1. 0.372 std. min.

2. 0.237

3. 0.389

4. 0.2735. 0.279

6. 0.155

7. 0.333

Identify the “bottleneck” or “line balance” operation

Calculate the standard time (in minutes) per unit How many units per 8-hour shift are expected?

At what production rate (units per minute) should this line be running?

What is the performance vs. standard if 1,150 units are produced in 8-hours?

PERFORMANCE



The percent performance versus standardcalculation is used for all production work, whether

single operator work or assembly line.

For example:

A single operator bench assembly job has a

standard time of 1.233 minutes. What is this job’seight-hour performance if 400 units are produced?

PERFORMANCE



Effect of Performance on Actual Labor Cost

1/performance x labor rate = actual labor cost

(The performance number is not in percent.)

Calculate the actual cost of labor given these assumptions: One operator bench assembly (from previous problem)

Operator earns $12.00 per hour

Operator produces 330 units in one 8-hour shift (std = 1.233 min.)

This calculation is possible for a part, a department, or the entire plant.

PERFORMANCE



Your plant manager is interested in a better understanding of yourplant’s labor cost. You decide to compute the effective actual direct

labor hourly wage rate, based upon the current labor standards, for the

past month. You have recently performed an audit of the standards

and are comfortable with their accuracy. Here are the assumptions:

Total hours earned (all products produced) 13,700 hours

Total hours used (100 people for 20 work days) 16,000 hours

Weighted average direct labor hourly wage rate $13.50

13,700 / 16,000 = 0.856 1 / 0.856 = 1.168 1.168 x $13.50 = $15.77

This information could be used as a benchmark from which to measure

improvements. It could, also, include indirect labor, if desired.

PRACTICE PROBLEMS



HANDOUT

Perform the calculations required to answer thequestions on the practice problems.

BIBLIOGRAPHY



(Page 1 of 2)

Greif, Michel, The Visual Factory,Productivity Press, 19896. p. 63

Barnes, Ralph M., Motion and TimeStudy Design and Measurement ofWork, 7th edition, John Wiley & Sons,

198018. p. 40622. p. 17423. p. 17526. p. 28928. p. 29130. p. 284

34. p. 309

Niebel, Benjamin W., Motion and TimeStudy, seventh edition, Irwin, 19821. p. 63. pp. 10 & 115. p. 1219. p. 29421. p. 134

31. p. 40133. p. 39135. pp. 386 & 38736. p. 38637. p. 420

Alexander, David C. and Pulat, BaburMustafa, Industrial Ergonomics APractitioner’s Guide, IndustrialEngineering and Management Press(IIE), 198524. p. 3

BIBLIOGRAPHY



(Page 2 of 2)

Meyers, Fred E. and Stewart,James R., Motion and Time Studyfor Lean Manufacturing, thirdedition, Prentice-Hall, 20022. p. 274. pp. 29 – 317. p. 88. pp. 9 & 109. p.1310. pp. 22- 2411. p. 1312. pp. 37 & 38

13. p. 4014. p. 3815. p. 4116. p. 57

Meyers, Fred E. and Stewart,James R., Motion and Time Studyfor Lean Manufacturing, thirdedition, Prentice-Hall, 2002(continued)

20. p. 67

25. p. 15927. p. 186

29. p. 186

38. p. 233

Karger, Delmar W. and Hancock,Walton M., Advanced WorkMeasurement, Industrial Press,1982

32 17 21

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