system design: process selection and facility layout pertemuan 07 mata kuliah: j0444 - manajemen...

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System Design: Process Selection and Facility

LayoutPertemuan 07

Mata kuliah : J0444 - Manajemen OperasionalTahun : 2010

Learning Objectives

• Explain the strategic importance of process selection.

• Explain the influence that process selection has on an organization.

• Describe the basic processing types. • Discuss automated approaches to processing. • Explain the need for management of

technology.

Learning Objectives

• List some reasons for redesign of layouts. • Describe the basic layout types. • List the main advantages and disadvantages of

product layouts and process layouts. • Solve simple line-balancing problems. • Develop simple process layouts.

• Process selection– Deciding on the way production of goods or services

will be organized

• Major implications– Capacity planning– Layout of facilities– Equipment– Design of work systems

Introduction

Forecasting

Product andService Design

TechnologicalChange

CapacityPlanning

ProcessSelection

Facilities andEquipment

Layout

WorkDesign

Process Selection and System Design

• Key aspects of process strategy– Capital intensive – equipment/labor

– Process flexibility

– Technology

– Adjust to changes

– Design

– Volume

– technology

Process Strategy

Technology

• Technology: The application of scientific discoveries to the development and improvement of products and services and operations processes.

• Technology innovation: The discovery and development of new or improved products, services, or processes for producing or providing them.

Kinds of Technology

• Operations management is primarily concerned with three kinds of technology:– Product and service technology– Process technology– Information technology

• All three have a major impact on:– Costs– Productivity– Competitiveness

Technology Competitive Advantage

• Innovations in– Products and services

• Cell phones• PDAs• Wireless computing

– Processing technology

• Increasing productivity• Increasing quality• Lowering costs

Technology Acquisition

• Technology can have benefits but …• Technology risks include:

– What technology will and will not do– Technical issues– Economic issues

• Initial costs, space, cash flow, maintenance• Consultants and/or skilled employees• Integration cost, time resources• Training, safety, job loss

• Variety– How much

• Flexibility– What degree

• Volume – Expected output

Job Shop

Batch

Repetitive

Continuous

Process Selection

• Job shop– Small scale

• Batch– Moderate volume

• Repetitive/assembly line– High volumes of standardized goods or services

• Continuous– Very high volumes of non-discrete goods

Process Types

Process Type

Job Shop Appliance repairEmergency

room

Ineffective

Batch Commercialbaking

ClassroomLecture

Repetitive Automotiveassembly

Automaticcarwash

Continuous(flow)

Ineffective Steel ProductionWater purification

Product and Service Processes

• Automation: Machinery that has sensing and control devices that enables it to operate– Fixed automation– Programmable automation

• Computer-aided design and manufacturing systems (CAD/CAM)

• Numerically controlled (NC) machines • Robot• Manufacturing cell• Flexible manufacturing systems(FMS)• Computer-integrated manufacturing (CIM)

Automation

What is Facility Layout

• Location or arrangement of everything within & around buildings

• Objectives are to maximize– Customer satisfaction – Utilization of space, equipment, & people– Efficient flow of information, material, &

people– Employee morale & safety

Strategic Importance of Layout

Proper layout enables:• Higher utilization of space, equipment,and

people• Improved flow of information, materials, or

people• Improved employee morale and safer working

conditions• Improved customer/client interaction• Flexibility

Types of Layouts

• Fixed-position layout• Process-oriented layout• Office layout• Retail layout• Warehouse layout• Product-oriented layout

Six Layout Strategies

• Fixed-position layout– large bulky projects such as ships and buildings

• Process-oriented layout– deals with low-volume, high-variety production (“job

shop”, intermittent production)

• Office layout– positions workers, their equipment, and

spaces/offices to provide for movement of information

Six Layout Strategies - continued

• Retail/service layout– allocates shelf space and responds to customer

behavior

• Warehouse layout– addresses trade-offs between space and material

handling

• Product-oriented layout– seeks the best personnel and machine use in

repetitive or continuous production

Layout Example - Office

Raw materialsor customer

Finished itemStation

2

Station 2

Station 3

Station 3

Station 4

Station 4

Material and/or labor

Station 1

Material and/or labor

Material and/or labor

Material and/or labor

Used for Repetitive or Continuous Processing

Product Layout

1 2 3 4

5

6

78910

In

Out

Workers

A U-Shaped Production Line

Dept. A

Dept. B Dept. D

Dept. C

Dept. F

Dept. E

Used for Intermittent processingJob Shop or Batch Processes

Process Layout(functional)

Process Layout

Requirements of a Good Layout

an understanding of capacity and space requirements

selection of appropriate material handling equipment

decisions regarding environment and aesthetics

identification and understanding of the requirements for information flow

identification of the cost of moving between the various work areas

Constraints on Layout Objectives

• Product design & volume• Process equipment & capacity• Quality of work life• Building and site

Areas of Concern in Layout Strategy

LayoutStrategy

MaterialFlow

Communication

WorkCell

Safety

MaterialAttributes

Warehousing

ServiceAreas

Fixed-Position Layout

• Design is for stationary project • Workers and equipment come to site• Complicating factors

– Limited space at site– Changing material needs

Process-Oriented Layout• Design places departments with large flows of

material or people together• Department areas having similar processes

located in close proximity– e.g., All x-ray machines in same area

• Used with process-focused processes

Steps in Developing a Process-Oriented Layout

1 Construct a “from-to matrix”2 Determine space requirements for each

department3 Develop an initial schematic diagram4 Determine the cost of this layout5 By trial-and-error (or more sophisticated

means), try to improve the initial layout6 Prepare a detailed plan that evaluates factors

in addition to transportation cost

Cost of Process-Oriented Layout

j department and i department

between load a move cost to C

j department toi department

from moved loads ofnumber X

sdepartment individual ji,

sdepartmentor

centers work ofnumber totaln where

CX cost Minimize

ij

ij

n

1i

n

1jijij

Interdepartmental Flow of Parts1 2 3 4 5 6

1

2

3

4

5

6

50 100 0 0 20

30 50 10 0

20 0 100

50 0

0

Interdepartmental Flow Graph Showing Number of Weekly Loads

100

50 30

1020

50

20

10050

1 2 3

4 5 6

Possible Layout 1

Assembly

Department

(1)

Printing

Department

(2)

Machine Shop

Department

(3)

Receiving

Department

(4)

Shipping

Department

(5)

Testing

Department

(6)

Room 1 Room 2 Room 2

Room 4 Room 5 Room 6

60’

40’

Interdepartmental Flow Graph Showing Number of Weekly Loads

100

50

30

10

20

50

20 10050

1 2 3

4 5 6

Possible Layout 3

Painting

Department

(2)

Assembly

Department

(1)

Machine Shop

Department

(3)

Receiving

Department

(4)

Shipping

Department

(5)

Testing

Department

(6)

Room 1 Room 2 Room 2

Room 4 Room 5 Room 6

60’

40’

• Cellular Production– Layout in which machines are grouped into a

cell that can process items that have similar processing requirements

• Group Technology– The grouping into part families of items with

similar design or manufacturing characteristics

Cellular Layouts

Cellular Layout - Work Cells

• Special case of product-oriented layout - in what is ordinarily a process-oriented facility

• Consists of different machines brought together to make a product

• Temporary arrangement only• Example: Assembly line set up to produce

3000 identical parts in a job shop

Improving Layouts by Moving to the Work Cell Concept

Work Cell Floor Plan

OfficeOffice

Tool RoomTool RoomWork CellWork Cell

SawsSaws DrillsDrills

Office Layout

Design positions people, equipment, & offices for maximum information flow

Arranged by process or product Example: Payroll dept. is by process

Relationship chart used Examples

Insurance company Software company

Office Layout Floor Plan

AccountingAccounting

ManagerManager Brand XBrand X

FinanceFinanceFin. Acct.

Relationship Chart

1 PresidentO

2 Costing UA A

3 Engineering IO

4 President’s Secretary

1122

33

Ordinary closeness: President (1) & Costing (2)

Absolutely necessary: President (1) & Secretary (4)

44

I = Important

U = Unimportant

Office Relationship Shart

1 President

2 Chief Technology Officer

3 Engineer’s Area

4 Secretary

5 Office entrance

7 Equipment cabinet

8 Photocopy equipment

9 Storage room

9 Storage room

U

I

I

A

U

O

E

I

O

E

I

O

A

O

A

X

O

U

E

A

I

I

E

U

A

I

I

E

A

X

U

U

OOU O

Val. Closeness

A Absolutely necessary

E Especially important

I Important

O Ordinary OK

U Unimportant

X Not desirable

Retail/Service Layout

Design maximizes product exposure to customers Decision variables

Store flow pattern Allocation of (shelf) space to products

Types Grid design Free-flow design

Video

Retail /Service Layout -Grid Design

OfficeOffice CartsCarts Check-Check-outout

Grocery StoreGrocery StoreMeatBread

Milk

Pro

du

ceF

roze

n F

oo

ds

Store Layout - with Dairy, Bread, High Drawer Items in Corners

Retail/Service Layout - Free-Flow Design

FeatureFeature

Display Display TableTable

Trans.Trans.CounterCounter

Apparel StoreApparel Store

Retail Store Shelf Space Planogram

Computerized tool for shelf-space management

Generated from store’s scanner data on sales

Often supplied by manufacturer

2 ft2 ft..

55 facingsfacings

VO

-5

VO

-5

VO

-5

SU

AV

E

SU

AV

E

VO

-5P

ER

T

PE

RT

PE

RT

PE

RT

PE

RT

VO

-5

A Good Service Layout (Servicescape) Considers

• Ambient conditions - background characteristics such as lighting, sound, smell, and temperature.

• Spatial layout and functionality - which involve customer circulation path planning

• Signs, Symbols, and Artifacts - characteristics of building design that carry social significance

Warehouse Layout

Design balances space (cube) utilization & handling cost

Similar to process layout Items moved between dock

& various storage areas

Optimum layout depends on Variety of items

stored Number of items picked

Warehouse Layout Floor Plan

ZonesZones

ConveyorConveyorTruckTruck

Order PickerOrder Picker

Product-Oriented Layout

• Facility organized around product• Design minimizes line imbalance

– Delay between work stations

• Types: Fabrication line; assembly line

Product-Oriented Requirements

• Standardized product• High production volume• Stable production quantities• Uniform quality of raw materials &

components

Line Balancing is the process of assigning tasks to workstations in such a way that the workstations have approximately equal time requirements.

Design Product Layouts: Line Balancing

Assembly Line Balancing

• Analysis of production lines• Nearly equally divides work between

workstations while meeting required output

• Objectives– Maximize efficiency– Minimize number of

work stations

Assembly Line BalancingThe General Procedure

• Determine cycle time by taking the demand (or production rate) per day and dividing it into the productive time available per day

• Calculate the theoretical minimum number of work stations by dividing total task time by cycle time

• Perform the line balance and assign specific assembly tasks to each work station

Assembly Line Balancing Steps

1. Determine tasks (operations)2. Determine sequence3. Draw precedence diagram4. Estimate task times5. Calculate cycle time 6. Calculate number of work stations7. Assign tasks 8. Calculate efficiency

A B

E H

C

D

F G I10 Min.10 Min.

55

1111

1212

33 77 33

44

1111

Precedence Diagram Example

Assembly Line Balancing Equations

Six Station Solution

A B

C

E

D

F G

I

H

10 11

5

3 7

3

1112

The End

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