Process Structures[1]

8/8/2019 Process Structures[1]

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Process Technology

It refers to the equipment,

people and systems used toproduce a firm·s products and

services.



2

Production Process Structures

Flow Processes

Job-shop Processes

Cellular Processes

Project Processes



Selection of a process structure

Expected volume & demand pattern

for products No. of products to be made & types

of processing each requires

Made to stock or Made to order Physical characteristics & specific

technologies required



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Flow ProcessesT o structure the process according to

the ´flowµ of the products orsequence of tasks that must beperformed to make them.

1 2 3 4 5

Materials

Work StationsOut-

putProductFlow



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Flow Processes Continuous Flow Process

-- Paper manufacturing Repetitive or Discrete Flow Process

-- Automobile assembling

Disconnected or Batch Flow Process-- Book manufacturing



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Continuous Flow Process Primarily used in process industries

Designed to produce large volumes ofa small variety of uniform products

Processing subject to very strict

specifications Highly interconnected structure



7

Continuous Flow Process Used for some aspects of

production process for discreteproducts

Very capital intensive

Highly automated and computerized Low: direct labor costs & per unit

production costs



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Repetitive Flow Process Often called Line process or discrete

flow process

Common version is an assembly line

Large quantities of narrow range ofproducts

Fixed sequence of productio n tasks

Us e o f sp eci ali zed equi p ment

Greater Auto matio n



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Repetitive Flow Process:

Problems Decomposing

Assigning and combining Accommodating

Adjusting to variation & uncertainties



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Advantages: Continuous &

Repetitive Flow Process Equipment can be specialized

Jobs can be specialized Material handling can be simplified

W-I-P inventories are small

Space utilization is efficient

Quality conformance is easier to

achieve



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Advantages Production scheduling and

coordination are relatively easy Costs are easy to monitor



12

Disadvantages Inflexible

High initial costs Work can become tedious and boring

Production system is extremely

vulnerable



13

Batch Flow Process Also called disconnected flow process

Produce a variety of products indifferent volumes

Use special equipment and jobs at each

workstation Variation in processing times & batch

sizes



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Batch Flow Process Material handling depends on

standard operations, & there is W-I-Pinventory

T rade-off between flexibility and

efficiency



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Batch Flow Process Adv: Flexibility, Low Cost, High

Capacity Utilization, Staffadvantages.

Disadv: Expensive for high volumes,

Idling of resources, Large in-processinventory, Costly material handling

equipments, Requires more space.



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Job-Shop Process Produce small quantity of a wide

variety of products

Systems divided into work centers ordepartments that are organizedaround common activities.

Products can move among workcenters in any sequence providingmaximum flexibility.



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Advantages: Job-shop Process Production Flexibility

Ability to accommodate differentprocessing times & lot sizes

Low initial costs for general purpose

equipment Greater work satisfaction because of

variety of work performed.



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Disadvantages: Job-shop

Process General purpose equipment usually less

efficient More skilled, higher paid employees

needed Less efficient but more flexible

material-handling methods W-I-P inventories are needed for

keeping work centers operating & forscheduling flexibility.



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Disadvantages: Job-Shop

Process Require more space

Quality conformance is difficult Variability makes scheduling and

coordinating very complex

Long throughput times

Difficult to determine profitability of

individual product.



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Why Job-Shop? Variety or volume of products

produced make the use of flow process

impractical. (companies competing

through product customization)

Startup costs of making new productsin small quantities are normally much

less.



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Cellular Process A mixture of mini flow processes, called

work cells, & a job-shop operation.

Dividing products that require similarprocessing steps in the same sequence.

Work cell created to perform the stepsin the designated sequence for all theproducts.

´Remainderµ job-shop subsystem (cell).



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Cellular Process Most commonly used as substitutes

for job-shop that need increasedproductivity.

Used in place of flow processes to

obtain greater flexibility. A popular way to organize service

operations.



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Advantages: Cellular Process Material handling & transport are

reduced. Setup times are reduced.

T hroughput time is reduced.

In-process inventories are smaller. Less space is needed.



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Advantages: Cellular Process T otal equipment costs often

decrease. Workers enjoy more satisfaction.

Quality improves.



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Disadvantages: Cellular

ProcessSuccessful implementation requires

considerable amount of work &expertise to:

Characterize & Classify products

Design appropriate work cells



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Project Processes Short life-cycle with a definite

beginning and a definite end.

Producing one-of-a-kind products

Likely to utilize similar skills and

equipment. T he process itself has to be

customized.



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Project Processes Manpower deployment: tricky

Matrix

form of organization is suitablewhen multiple projects are beinghandled.

Interdependent activities

Adv: Flexibility to customize theproduct.

Dis adv: Expense.



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List of Projects Setting up a Nuclear Power Plant

Launching a new product in the market

Conducting an EDP like Finance for non-finance executives

Organizing an Annual Sales Conference

Computerization of Inventory Building a modern hospital or stadium

Modernization of outdated textile mills

Community development projects



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Dominant Operations

Management Issues: How to coordinate the wide variety of

resources that are needed for thecurrent project, as well as for other

projects of the organization?

How to complete the project onschedule and within budget?



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Types of Non-Manufacturing

operations (Service)1. On the basis of process performed:

Standard Service

Custom Service

2. On the basis of product dealt: Providers of tangible products

Providers of service

3. Participation of customer in theprocess



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Challenges of Service

Operations Not easy to measure productivity

Difficult to establish qualitystandards

Service providers generally have

contact with customers Cannot maintain inventory



32

C AD/C AM Systems Systems integrated with computer-

controlled machines Once a product or part design has

been completed on the CAD system, it

can be automatically encoded asmachine instructions for computer-

controlled machines.



33

Advantages: C AD Systems Saves:

Considerable time Cost of hand-programming the

machine

Reduces chances of errors.



34

Flexible Manufacturing

Systems (FMS) Self-contained systems of computer-

controlled machines, a tool-changingsystem, and a material-handling

system.

Vary widely in their complexity andcapabilities.



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Advantages: FMS Flexibility

Cost and time reductions

Better material handling

Minimal in-process waiting

Quicker machine setups Smaller quantities at lower cost

Firms can respond to demand

fluctuations more quickly.



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Disadvantages: FMS Expensive

Requires considerable expertiseand planning to implement

successfully.



37

Computer-integrated

manufacturing (CIM) T ie all the database systems and all

the manufacturing equipment &

subsystems together into a single

integrated system.

Control and coordinate every phase ofproduction, from initial order receipt

to shipment and billing.



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CIM examples Motorola, T exas Instruments,

T oshiba, & others have greatlyintegrated their design, sales,

scheduling, manufacturing,

purchasing, and accountingsystems.

Documents

Process Structures[1]