Chapter 6 process selection and facility layout

Chapter 6

Process Selection and Facility Layout

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Learning Objectives (1 of 2)

You should be able to:

6.1 Explain the strategic importance of process selection and the influence it has on the organization and its supply chain

6.2 Name the two main factors that influence process selection

6.3 Compare the four basic processing types

6.4 Explain the need for management of technology

6.5 List some reasons for redesign of layouts

6.6 Describe product layouts and their main advantages and disadvantages

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Learning Objectives (2 of 2)

6.7 Describe process layouts and their main advantages and disadvantages

6.8 Solve simple line-balancing problems

6.9 Develop simple process layouts

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Learning Objective 6.1

Process Selection

Process selection

Refers to deciding on the way production of goods or services will be organized

It has major implications for

Capacity planning

Layout of facilities

Equipment

Design of work systems

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Learning Objective 6.1

Process Selection and System Design

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Learning Objective 6.1

Process Strategy

Key aspects of process strategy:

Capital intensity

The mix of equipment and labor that will be used by the organization

Process flexibility

The degree to which the system can be adjusted to changes in processing requirements due to such factors as

Product and service design changes

Volume changes

Changes in technology

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Learning Objective 6.2

Process Selection – Key Questions

Two key questions in process selection:

How much variety will the process need to be able to handle?

How much volume will the process need to be able to handle?

Job Shop

Batch

Repetitive

Continuous

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Learning Objective 6.3

Job Shop Batch Repetitive/ Assembly Continuous
Description Customized goods or services Semi-standardized goods or services Standardized goods or services Highly standardized Goods or services
Advantages Able to handle a wide variety of work Flexibility; easy to add or change products or services Low unit cost, high volume, efficient Very efficient, very high volume
Disadvantages Slow, high cost per unit, complex planning and scheduling Moderate cost per unit, moderate scheduling complexity Low flexibility, high cost of downtime Very rigid, lack of variety, costly to change, very high cost of downtime
Types of Processing

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Sustainable Production of Goods and Services

There is increasing pressure for organizations to operate sustainable production processes

According to the Lowell Center for Sustainable Production:

“Sustainable Production is the creation of goods and services using processes and systems that are: non-polluting; conserving of energy and natural resources; economically efficient; safe and healthful for workers, communities, and consumers; and, socially and creatively rewarding for all working people.”

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Process and Information Technology

Process and information technology can have a major impact on costs, productivity and competitiveness:

Process technology

Methods, procedures, and equipment used to produce goods and provide services

Information technology

The science and use of computers and other electronic equipment to store, process, and send information

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Learning Objective 6.4

The Need to Manage Technology

Process technology and information technology can have a profound impact on:

Costs

Productivity

Competitiveness

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Automation

Automation

Machinery that has sensing and control devices that enable it to operate automatically

Fixed automation

Programmable automation

Flexible automation

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Programmable Automation

Programmable automation

Involves the use of high-cost, general-purpose equipment controlled by a computer program that provides both the sequence of operations and specific details about each operation

Computer-Aided Manufacturing (CAM)

The use of computers in process control, ranging from robots to automated quality control

Numerically Controlled (N/C) Machines

Machines that perform operations by following mathematical processing instructions

Robot

A machine consisting of a mechanical arm, a power supply, and a controller

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Flexible Automation

Flexible automation

Evolved from programmable automation. It uses equipment that is more customized than that of programmable automation. A key difference between the two is that flexible automation requires significantly less changeover time.

FMS (Flexible Manufacturing System)

A group of machines designed to handle intermittent processing requirements and produce a variety of similar products

CIM (Computer Integrated Manufacturing)

A system for linking a broad range of manufacturing activities through an integrated computer system

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Flexible Manufacturing System (FMS)

FMS

A group of machines designed to handle intermittent processing requirements and produce a variety of similar products

Have some of the benefits of automation and some of the flexibility of individual, or stand-alone, machines

Includes supervisory computer control, automatic material handling, and robots or other automated processing equipment

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Computer Integrated Manufacturing (CIM)

CIM

A system for linking a broad range of manufacturing activities through an integrated computer system

Activities include

Engineering design

FMS

Purchasing

Order processing

Production planning and control

The overall goal of CIM is to link various parts of an organization to achieve rapid response to customer orders and/or product changes, to allow rapid production and to reduce indirect labor costs

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Facilities Layout

Layout

The configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system

Facilities layout decisions arise when:

Designing new facilities

Re-designing existing facilities

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Learning Objective 6.5

The Need for Layout Planning

Inefficient operations

High cost

Bottlenecks

Accidents or safety hazards

Changes in product or service design

Introduction of new products or services

Changes in output volume or product mix

Changes in methods or equipment

Changes in environmental or other legal requirements

Morale problems

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Learning Objective 6.5

Layout Design Objectives

Basic objective

Facilitate a smooth flow of work, material, and information through the system

Supporting objectives

Facilitate product or service quality

Use workers and space efficiently

Avoid bottlenecks

Minimize material handling costs

Eliminate unnecessary movement of workers or material

Minimize production time or customer service time

Design for safety

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Basic Layout Types

Product layouts

Process layouts

Fixed-position layout

Combination layouts

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Learning Objective 6.6

Repetitive Processing: Product Layouts (1 of 2)

Product layout

Layout that uses standardized processing operations to achieve smooth, rapid, high-volume flow

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Learning Objective 6.6

Repetitive Processing: Product Layouts (2 of 2)

Used for Repetitive Processing

Repetitive or Continuous

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Learning Objective 6.6

Product Layouts: Advantages & Disadvantages (1 of 2)

Advantages

High rate of output

Low unit cost

Labor specialization

Low material handling cost per unit

High utilization of labor and equipment

Established routing and scheduling

Routine accounting, purchasing, and inventory control

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Learning Objective 6.6

Product Layouts: Advantages & Disadvantages (2 of 2)

Disadvantages

Creates dull, repetitive jobs

Poorly skilled workers may not maintain equipment or quality of output

Fairly inflexible to changes in volume or product or process design

Highly susceptible to shutdowns

Preventive maintenance, capacity for quick repair and spare-parts inventories are necessary expenses

Individual incentive plans are impractical

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Learning Objective 6.7

Non-repetitive Processing: Process Layouts

Process layouts

Layouts that can handle varied processing requirements

Used for Intermittent processing

Job Shop or Batch

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Learning Objective 6.7

Process Layouts: Advantages & Disadvantages (1 of 2)

Advantages

Can handle a variety of processing requirements

Not particularly vulnerable to equipment failures

General-purpose equipment is often less costly and easier and less costly to maintain

It is possible to use individual incentive systems

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Learning Objective 6.7

Process Layouts: Advantages & Disadvantages (2 of 2)

Disadvantages

In-process inventories can be high

Routing and scheduling pose continual challenges

Equipment utilization rates are low

Material handling is slow and inefficient

Reduced spans of supervision

Special attention necessary for each product or customer

Accounting, inventory control, and purchasing are more involved

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Fixed Position Layouts

Fixed position layout

Layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed

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Combination Layouts

Some operational environments use a combination of the three basic layout types:

Hospitals

Supermarket

Shipyards

Some organizations are moving away from process layouts in an effort to capture the benefits of product layouts

Cellular manufacturing

Flexible manufacturing systems

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Service Layouts (1 of 2)

Service layouts can be categorized as: product, process, or fixed position

Service layout requirements are somewhat different due to such factors as:

Degree of customer contact

Degree of customization

Common service layouts:

Warehouse and storage layouts

Retail layouts

Office layouts

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Service Layouts (2 of 2)

Two key factors:

Customer contact

Degree of customization

Layouts:

Warehouse and storage layouts

Retail layouts

Office layouts

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Cellular Layouts

Cellular production

Layout in which workstations are grouped into a cell that can process items that have similar processing requirements

Groupings are determined by the operations needed to perform the work for a set of similar items, part families, that require similar processing

The cells become, in effect, miniature versions of product layouts

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Group Technology

Group technology

The grouping into part families of items with similar design or manufacturing characteristics

Design characteristics:

Size

Shape

Function

Manufacturing or processing characteristics

Type of operations required

Sequence of operations required

Requires a systematic analysis of parts to identify the part families

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Learning Objective 6.8

Designing Product Layouts: Line Balancing

The goal of a product layout is to arrange workers or machines in the sequence that operations need to be performed

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Learning Objective 6.8

Line Balancing (1 of 2)

Line balancing

The process of assigning tasks to workstations in such a way that the workstations have approximately equal time requirements

Goal:

Obtain task grouping that represent approximately equal time requirements since this minimizes idle time along the line and results in a high utilization of equipment and labor

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Learning Objective 6.8

Line Balancing (2 of 2)

Why is line balancing important?

It allows us to use labor and equipment more efficiently

To avoid fairness issues that arise when one workstation must work harder than another

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Learning Objective 6.8

Cycle Time

Cycle time

The maximum time allowed at each workstation to complete its set of tasks on a unit

Cycle time also establishes the output rate of a line

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Learning Objective 6.8

How Many Workstations Are Needed?

The required number of workstations is a function of

Desired output rate

Our ability to combine tasks into a workstation

Theoretical minimum number of stations

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Learning Objective 6.8

Precedence Diagram

Precedence diagram

A diagram that shows elemental tasks and their precedence requirements

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Learning Objective 6.8

Assigning Tasks to Workstations

Some heuristic (intuitive) rules:

Assign tasks in order of most following tasks

Count the number of tasks that follow

Assign tasks in order of greatest positional weight

Positional weight is the sum of each task’s time and the times of all following tasks

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Learning Objective 6.8

Measuring Effectiveness

Balance delay (percentage of idle time)

Percentage of idle time of a line

Efficiency

Percentage of busy time of a line

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Learning objective 6.9

Designing Process Layouts

The main issue in designing process layouts concerns the relative placement of the departments

Measuring effectiveness

A major objective in designing process layouts is to minimize transportation cost, distance, or time

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Learning Objective 6.9

Information Requirements

In designing process layouts, the following information is required:

A list of departments to be arranged and their dimensions

A projection of future work flows between the pairs of work centers

The distance between locations and the cost per unit of distance to move loads between them

The amount of money to be invested in the layout

A list of any special considerations

The location of key utilities, access and exit points, etc.

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Learning Objective 6.9

Process Layout Problem (1 of 2)

Distance between locations in meters

To A To B To C
From A 20 40
From B 30
From C
Interdepartmental work flows (loads per day)

To 1 To 2 To 3
From 1 30 170
From 2 100
From 3
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Learning Objective 6.9

Process Layout Problem (2 of 2)

Dept. Loads Location Distance (meters) Load Distance Score
1 to 2 170 A to B 20 170×20 = 3,400
1 to 3 30 A to C 40 30×40 = 1,200
2 to 3 100 B to C 30 100×30 = 3,000
Total 7,600
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End of Presentation

© McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education.

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