1. Chapter 6
Process Selection and
Facility Layout

2. Introduction Process selection Major implications
Deciding on the way production of goods or services will be organized
Major implications
Capacity planning
Layout of facilities
Equipment
Design of work systems

3. Process Selection and System Design
Forecasting
Product and Service Design
Technological Change
Capacity Planning
Process Selection
Facilities and Equipment
Layout
Work Design

4. Process Selection Batch Variety Flexibility Volume Job Shop Repetitive
How much
Flexibility
What degree
Volume
Expected output
Job Shop
Repetitive
Continuous

5. Types of Operations INCREASED VOLUME Project/ Job Shop Unit or Batch
Mass/
Assembly
Continuous
INCREASED VOLUME

6. Process Design Project Processes (Fixed Position)
Intermittent Flow Processes (Batch Shops)
Continuous Flow Processes (Flow Shops)
Processing Industries (Continuous)

7. Job Shop (Fixed Position)
People and material move
Have limited duration
Small scale
Examples
Housing
Ship building
Dam
Appliance Repair

8. Intermittent Flow Processes (Batch Shops)
No pattern exists between process of different products
Appropriate to service organizations
Moderate volume
Example:
Machine Shops
Auto Repair Shops
Commercial Bakery
Classroom Lecture

9. Continuous Flow Processes (Flow Shops)
Sequences are the same (Standard Routes)
High volumes of standardized goods or services
Examples:
Assembly Lines
Car Wash

10. Processing Industries (Continuous Flow)
One primary input (gas, wheat, etc) is converted to multiple outputs
Very high volumes of non-discrete goods
Example:
Petroleum
Chemicals
Food Industries

11. Process Characteristics
Project
Intermittent
Continuous
PRODUCT
Order Type
Single Unit
Batch
Continuous or large batch
Flow of Product
None
Jumbled
Sequence
Product Variety
Very High
High
Low
Market type
Unique
Custom
Mass
Volume
Medium

12. Process Characteristics
Project
Intermittent
Continuous
CAPITAL
Inventory
Medium
High
Low
Equipment
General Purpose
Special Purpose
LABOR
Skills
Task Type
Non-routine
Repetitive

13. Process Characteristics
Project
Intermittent
Continuous
CONTROL
Production
Difficult
Easy
Quality
Inventory
EQUIPMENT
General Purpose
Special Purpose

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

17. Automation Computer-aided design and manufacturing systems (CAD/CAM)
Numerically controlled (NC) machines
Robot
Manufacturing cell
Flexible manufacturing systems(FMS)
Computer-integrated manufacturing (CIM)

19. Functional Areas Being Linked to Manage the Flow of Information
Design
Handling of Materials
Storage and Retrieval of Information
Control of Machine Tools

20. Design CAD No longer limited to the top, side and front views
Can observe the rotation of the part about any axis on the screen
Generally, improves productivity in the drafting room by a factor of 3 or more
At GM, the redesign of a single auto model requires 14 months instead of 24 months
The time needed to design custom values reduced from six months to one

21. Handling of Materials
Data processing technology can be applied to the control of 3 general kids of machines in the factory:
Machines that store, retrieve, or transport materials
Machines that process the materials
Robots

22. Handling of Materials
Automatic storage and retrieval systems transfer pallets of material into or out of storage rack up to 100 feet high
Mini Loaders
Hold drawers of small parts
Automatic Warehouse
Automatic shuttle takes the place of the fork-lift truck and its human operations

23. Storage and Retrieval of InformationGT
The formation of part families based on design or manufacturing similarities (or both)
Classification of parts speed up the design of similar parts in the company
Only 20% of the parts actually need new design. 40% could be built from an existing design and the other 40% could be created by modifying an existing design.
Automatic guided vehicle

24. Control of Machine ToolsNC
Machine tools run by programs
DNC
Direct numerically controlled machine tools
Several computerized, NC machine tools are linked by a hierarchy of computers

25. Control of Machine Tools
FMS
Flexible Manufacturing System
It consists of an integrated collection of:
Automated Production Processes NC
Robots
A material transport system
An automated transfer line

27. Control of Robots Robots Main features: Applications
A programmable machine capable of moving materials and performing repetitive tasks.
Main features:
They are flexible
They eliminate the need for operators
Applications
Loading and unloading of machine tools
Jobs that are dirty, hazardous, unpleasant, or monotonous

30. The Operating Capabilities of the Factory of the Future
Economic order quantity approaches 1
Variety has no cost penalty (economy of slope)
Rapid response to changes in product design, market demand, and production mix
Unmanned and continuous operation is standard
Consistent high levels of quality and accuracy and repeatability introduce higher levels of certainty into the production planning and control activity

31. Facilities Layout
Layout: the configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system

32. Importance of Layout Decisions
Requires substantial investments of money and effort
Involves long-term commitments
Has significant impact on cost and efficiency of short-term operations

33. Basic Layout Types Product layout Process layout Fixed Position layout
Layout that uses standardized processing operations to achieve smooth, rapid, high-volume flow
Process layout
Layout that can handle varied processing requirements
Fixed Position layout
Layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed

34. Product Layout Raw materials or customer
Station 1
Station 2
Station 3
Station 4
Finished item
Material
and/or labor
Material
and/or labor
Material
and/or labor
Material
and/or labor
Used for Repetitive or Continuous Processing

35. Advantages of Product Layout
High rate of output
Low unit cost
Labor specialization
Low material handling cost
High utilization of labor and equipment
Established routing and scheduling
Routing accounting and purchasing

36. Disadvantages of Product Layout
Creates dull, repetitive jobs
Poorly skilled workers may not maintain equipment or quality of output
Fairly inflexible to changes in volume
Highly susceptible to shutdowns
Needs preventive maintenance
Individual incentive plans are impractical

37. Assembly Line Balancing
Cycle time
The time required to produce one part is called the cycle time, or the maximum time allowed at any one work station
Assembly Line Balancing
Given a cycle time, find the minimum number of work stations or minimize the cycle time for a given number of work stations

38. Assembly Line Balancing - Example
Task
Time (min)
Immediate Predecessors A
0.2
----- B
0.3 C D
0.25 E
0.15
B,C F
D,E
Total
1.4

39. Assembly Line Balancing

40. Assembly Line Balancing
CYCLE TIME
.30 £ C £ 1.40
C = productive time/output rate
C = (8hr x 60min) =.5 min
960
Number of work stations, N = total time/C
N = 140 = 2.8 =3 .5

41. Solution to Assembly Line Balancing Problem
Station Tasks Assigned Total Task Time Idle Time
1 A, B
2 C, D
3 E, F
TOTAL

42. Line Balancing Rules 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.

43. Assembly Line Balancing Solution
Line Efficiency = Total Work Content
C x N
Efficiency = 1.40 = .93 or 93%
.5 x 3
Balance Delay = 1 – efficiency = = 7%

44. Example 2
0.2
0.2
0.3 a b e
0.8
0.6 c d f g h
1.0
0.4
0.3

45. Solution to Example 2 a b e f d g h c Station 1 Station 2 Station 3

46. A U-Shaped Production Line1 2 3 4 5 6 7 8 9 10 In
Out
Workers

47. Process Layout (functional)
Assume we have the following departments:
Accounting (A)
Production Planning (P)
Customer Service (C)
Sales (S)
What arrangement would be better?

48. Used for Intermittent processing
Job Shop or Batch A P C S S C A P

49. Intermittent Process Criteria Desirability ranking
Volume of interaction
Cost of interaction
Distance
Time
Safety
Facility Limitations

50. Advantages of Process Layouts
Can handle a variety of processing requirements
Not particularly vulnerable to equipment failures
Equipment used is less costly
Possible to use individual incentive plans

51. Disadvantages of Process Layouts
In-process inventory costs can be high
Challenging routing and scheduling
Equipment utilization rates are low
Material handling slow and inefficient
Complexities often reduce span of supervision
Special attention for each product or customer
Accounting and purchasing are more involved

52. Cellular Layouts Cellular Production Group Technology
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

53. Process Layout - Example
Process Layout - work travels to dedicated process centers
Milling
Assembly & Test
Grinding
Drilling
Plating

54. Functional Layout Gear cutting Mill Drill Lathes Grind Heat treat
Assembly
111
333
222
444
1111
2222
3333
44444
333333
22222

55. Cellular Manufacturing Layout – Group Technology
-1111
- 2222
Assembly
- 3333
- 4444
Lathe
Mill
Drill
Heat
treat
Gear
cut
Grind