OTM Slides1

8/3/2019 OTM Slides1

1/24

OPM 08E: Operation Transformation Management

Instructor: K. S. Thyagaraj


2/24

Design &

Develop-ment

Introduction

Growth Maturity Decline

Sales - low rising peak declining

Costs high high high low low

Profits negative negative small high declining

Competitors few few few many declining

Principle

Order

Qualifier

- price, quality price,

quality

quality,

delivery

dependability

quality, delivery

dependability

Principle

Order

Winner

- design &

performance,

delivery lead

time

product

variety,

delivery

lead time

product

variety (but to

a lesser extent

than in

Growth

Stage), price

price (only

successful

products

retained)

Product and Process Life Cycle


3/24

Design &

Develop-

ment

Introduction


Production

Planning

Techniques

CAD/CAM,

CIM

Concurrent

Engineering,

FMEA, DFSS

finite

scheduling

using MRP-II,

managing

bottleneck

using

OPT/TOC.

Designchanges (if

any) are

incorporated.

Less popular

designs

discarded.

finite

scheduling

using MRP-II,

incorporating

flexible, lean

production

practices with

JIT finalassembly

take

advantage of

economies-of-

scale, and

learning curve

to reduce cost

take advantage of

learning curve and

reduced product

variety to reduce

cost



4/24

Design &

Develop-

ment

Introduction


Push-Pull

boundary

- end-product

made-to-order,

componentsmade-to-stock.

Less of push

more of pull.

end-product

made-to-

order,components

made-to-

stock. More

of push Less

of pull.

end-products

and

componentsboth made-to-

stock. All of

Push

end-products and

components both

made-to-stock. Allof Push



5/24

Design &

Develop-

ment

Introduction


Production

Process

- fabrication is

process focused

with general

purpose

machines while

assembly is

product focused .

Machines are

preferably NC.

fabrication

using Group

Technology

with

general

purpose

machines

Assembly is

productfocused.

Machines

are

preferably

NC

fabrication

using Group

Technology

with special

purpose

machines with

product

focused

assembly.Machines are

preferably Hard

Automated .

fabrication using

Group Technology

with special

purpose machines

with product

focused assembly.

Machines are

(manually

operated or NC) orHard Automated if

sufficient volume

exists



6/24

Design &

Develop-

ment

Introduction


Facilitylayout highly flexiblefacility (job-

shop)

flexiblefacility dedicatedfacility (flow

shop)

general facility

Job Breadth

proportional

to workers

job

satisfaction

broad

(fabrication)

narrow

(assembly)

broad

(fabrication)

narrow

(assembly)

broad

(fabrication)

narrow

(assembly)

broad(fabrication)

narrow(assembly)



7/24

Medium Term Capacity Planning

Master Production Schedule- amount and need dates of specific end-items.

MPS exploded- gives parts and sub-assemblies requirements offset by lead

times- backward scheduled

thus load on individual work centers is obtained assuming infinite capacity, based

on one unit of average product in a product family, and std. hrs obtained using

performance measurement.

10-20% of lead time is comprised of set-up and run-time

remaining 80-90% of lead time the job spends waiting to be moved, being moved

or in queue.


8/24

Medium Term Capacity Planning: Improve standard lead-time

Reduce set-up time(SMED/OTED)

Improve job movement improve workplace layout - waiting to be moved, beingmoved .

For functional or process layout Computerized Relative Allocation of Facilities(CRAFT)

Combination layout Process Layout for Fabrication and Product Layout forassembly

GT (Cellular) Layout- parts requiring similar operations grouped together andundergo operations in a cell - machines arranged usually in U shape minimal

no. of workers

Assure Quality (TQM)

Reduce WIP inventory- queue in front of work centers- improve scheduling,Reliability Centered Maintenance (RCM).


9/24

Short Term Capacity Planning: Leveling Load in Process

Layout(job shop/batch flow)

Overlapping-dont wait for entire lot to be completed - send portion of completed

lot to next operation

Operation splitting- splits lot and sends to more than one machine

Lot splitting-breaking up order and running part of it ahead of schedule

Reduce load- reject orders- negotiate longer due dates or acceptance of part

shipments.

Simulate alternate MPS on resource requirement and obtain feasible MPS.

alternate routing, sub-contracting , scheduling overtime, reallocating work force,


10/24

Short Term Capacity Planning leveling load in Product

Layout(worker/machine paced line flow)

Assembly Line balancing


11/24

forward schedule- for custom order-delivery ASAP increases WIP

backward schedule- assembly reduces WIP.

Load Calculation- Gantt Chart

Job Shop Loading- each job can be processed at any of the machine center and

operation time varies at each machine

1. n jobs/n machines assignment method, and

2. n jobs/m(


12/24

Job Sequencing: N jobs-1 machine

1. Priority Rules:

(1)First Come First Serve,

(2) Shortest Processing Time( best except for variance of job lateness (Slack-

time per operation, Earliest Due Date), mean job tardiness (Critical Ratio))

(3)Slack-time per operation( (remaining time till due date -remaining

processing time)/remaining no. of operations),

(4) Critical Ratio (remaining processing time/remaining time till due date),

(5)Shortest Weighted Processing Time(delay cost, holding cost etc.)

2. Performance Measures: total, mean, and variance - flow time, lateness(+/-),

tardiness(+), and waiting time.

Short Term Capacity Planning in Job Shop


13/24

Load is in excess of capacity at bottleneck:

1. improve utilization2. reduce variation in standard cycle time

3. reduce standard cycle time, and

4. increase machine availability.

(1) and (2) improves efficiency at bottleneck

(3) and (4) increases capacity of bottleneck.

improve bottleneck utilization-see that bottleneck is not idle due to lack of material

increase machine availability in short term by scheduling additional shifts and/orovertime, outsourcing part of job, sub-contracting workers.

reduce standard run time- reduce set-up time (SMED/ OTED)- use CNC machines.

reduce variation in standard run time- use CNC machines

Short Term Capacity Planning- Batch Flow-Managing Bottleneck


14/24

Job Sequencing: Flow shop

1. N jobs-2 machine in series,

2. N jobs- 3 machines in series,

3. N jobs- M machines in series,

4. N jobs- M identical machines in parallel.

Short Term Capacity Planning- Batch Flow


15/24

Scheduling Process Industry-

inverted BOM- example Refinery- jet fuel unleaded regular gasoline-unleaded

high-octane gasoline- lot-size of each product to produce before changing over

production to next product to be determined

Scheduling Process Industry


16/24

Long Term Capacity Planning

Methodology : decision trees to evaluate alternatives

5-10 year decision period

Example: Increase machine capacity in long term- by replacing with or adding a

faster equipment.

Required number of machines=forecasted sales/(forecasted yield/machine)

P(r-c)+(1-P)(-c)>=0, P>c/r

Large capacity increments (money tied up vs. economies of scale) or small capacity

increments.

Alternative capacity (overtime + multiple shifts postpones tying up money) + small

capacity increments or large capacity increments.


17/24

Location of Facility and Transportation Design

Logistics cost (inventory, facility cost, and transportation) vs. Responsiveness.

Location model: Gravity vs. Network optimization model

Modes of transportation-air, package carriers, truck, rail, water, pipeline,

intermodal

Transportation Design evaluates options in terms of costs and complexity: (i)

transportation cost vs. inventory aggregation cost. (ii) transportation cost vs.

responsiveness

Routing methods: saving matrix method, generalized assignment method.


18/24

Service Industry


19/24

Performance Standards

Performance standards

Purpose of labor costing, wage incentive, scheduling and machine loading

Informal-supervisors estimate and past performance data

Work-Time distribution:

total standard time=normal time + standard allowance for personal time +

allowances for measured delays normal to the job + fatigue allowances

Performance Rating

normal time=actual observed time x performance rating/100.


20/24

Work Measurement

Work Measurement Systems

Stop watch time studies and simultaneous performance rating

Work sampling for proportion and non-cyclic pattern of work

normal time=(total observed time x work time in decimals x average performance

rating in decimals)/total pieces produced

Standard data work measurement systems

1. Universal data based on minute elements of motion

2. Standard data based on major elements of job

Wage incentive

1. Piece rate

2. Standard hour plan

(return)


21/24

SMED/OTED

Advantages of small Set-up time:

1. costs less can change set-up more often can produce in smaller batches

improved flexibility- reduced lead time

2. Smaller batchesdoesnt tie up machinery for long produce only what is needed

(MTO)

3. Production defects in a batch is identified quickly and can be corrected.

4. WIP is reduced (flow time=WIP/throughput) and flow time is reduced for a giventhroughput.


22/24

SMED/OTED

Internal tasks (stop-time activities)- machine has to be stopped

External tasks(run-time activities )- machine can be running.

Stage 1: Identify internal and external activities perform external activities while

machine is working on another batch- instead of during the set-up time.

Stage 2: convert as many internal activities to external activities- (takes a number of

months and some expenditure in tooling and equipment)

Stage 3: strive to eliminate /improve each elemt of the remaining internal and

external activities-(takes 2-3 years or even longer-considerable expenditure)

(return)


23/24

Reliability Centered Maintenance

Reliability Centered Maintenance.

Stage 1: what failures might occur, what effect these failures would have, and how

critical each would be in respect of both safety and economical consequence

(FMEA).

Stage 2: for each failure risk identified, deciding what action needs to be taken

either to remove the risk of the failure occurring, or to minimize its effects (RCM

diagram maximizing safety and obtain best value for money from maintenance

activity.)


24/24

Reliability Centered Maintenance

FMEA:

1. Define equipment to be analyzed

2. Construct block diagrams

3. Identify failure modes and effects.

4. Determine criticality of each failure mode.

5. Identify failure detection methods.

6. Identify action required.

7. Assess effects of action taken.

8. Documentation

RCM diagram:

Preparing the RCM maintenance schedules

Reducing the maintenance workload

OTM Slides1

Documents

Transcript of OTM Slides1