Ch6 Process -n- Layout

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What is designing a television?
TV at RANGS
Making sandwiches!
Adeyl Khan, Faculty, BBA, NSU
Process selection
 Deciding on the way production of goods or
services will be organized
 A process is any part of an organization that
transforms inputs into outputs, with the intention
that the output will be of greater value than the
input.
Adeyl Khan, Faculty, BBA, NSU
6-2
Flowchart for a new
product development
process
Major implications
•
•
•
•
Capacity planning
Layout of facilities
Equipment
Design of work systems
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3
Process Selection and System
Design- Figure 6.1
Forecasting
Capacity
Planning
Layout
Product and
Service Design
Technological
Change
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Facilities and
Equipment
Process
Selection
Work
Design
6-4
Process Strategy
Capital intensive
• Equipment
• Labor
Process flexibility
Technology
Adjust to changes
• Design
• Volume
• technology
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6-5
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.
Adeyl Khan, Faculty, BBA, NSU
OM & Technology
Relevant technology
• Product and service
technology
• Process technology
• Information technology
Product/Service Tech.
• Cell phones
• PDAs
• Wireless computing
Adeyl Khan, Faculty, BBA, NSU
Exam
Technology impact
• Costs
• Productivity
• Competitiveness
Competitive Advantage
Process Technology
• Increasing productivity
• Increasing quality
• Lowering costs
6-7
Technology risks
Exam
•
•
•
•
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
Adeyl Khan, Faculty, BBA, NSU
6-8
Process Selection
Intermittent process
Variety
• Process that produces a variety of
products, with different processing
requirements, in lower volumes.
• How much
Repetitive process
• What degree
• Process that produces one or a few
products, with the same or similar
processing requirements, usually in
higher volumes.
Volume
Adeyl Khan, Faculty, BBA, NSU
Flexibility
• Expected
output
6-9
Process Types and Product-Process Matrix
Low
Volume
One of a
Kind
Job
Shop
Multiple
Products,
Low
Volume
Few
High
Major
Volume,
Products,
High
Higher StandardVolume
ization
Job shop
• Small scale
Book
Writing
Batch
• Moderate volume
Batch
Movie
Theaters
Assembly
Line
Repetitive/assembly line
• High volumes of standardized
goods or services
Automobile
Assembly
Continuous
Continuous
Flow
Sugar
Refinery
Flexibility-Quality
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Dependability-Cost
• Very high volumes of nondiscrete goods
Product Profiling
 Linking key product or service requirements to
process capabilities
Key dimensions
•
•
•
•
•
Range of products or services
Expected order sizes
Pricing strategies
Expected schedule changes
Order winning requirements
Adeyl Khan, Faculty, BBA, NSU
Process selection
can be costly
• Equipment
• Layout of
facilities
6-11
Automation: Machinery that has sensing and
control devices that enables it to operate
 Fixed automation: Low production cost and high
volume but with minimal variety and high changes cost
 Assembly line
 Programmable automation: Economically producing a
wide variety of low volume products in small batches
 Computer-aided design and manufacturing systems
(CAD/CAM)
 Numerically controlled (NC) machines / CNC
 Industrial robots (arms)
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1
Automation: Machinery that has sensing and
control devices that enables it to operate …
 Flexible automation: Require less changeover time and
allow continuous operation of equipment and product
variety
 Manufacturing cell
 Flexible manufacturing systems: Use of high automation to
achieve repetitive process efficiency with job shop process
 Automated retrieval and storage
 Automated guided vehicles
 Computer-integrated manufacturing (CIM)
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1
Robot
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1
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15
Flexible Manufacturing System
 Group of machines that include supervisory
computer control, automatic material handling,
robots and other processing equipment
 Advantage:



reduce labor costs and more consistent quality
lower capital investment and higher flexibility than hard
automation
relative quick changeover time
 Disadvantage

used for a family of products and require longer planning
and development times
Adeyl Khan, Faculty, BBA, NSU
1
Computer-integrated manufacturing
 Use integrating computer system to link a broad
range of manufacturing activities, including
 engineering design
 Purchasing
 order processing
 production planning and control …
 Advantage:
 rapid response to customer order and product
change, reduce indirect labor cost, high quality
Adeyl Khan, Faculty, BBA, NSU
1
Service Process Design
 Establish boundaries
 Identify steps involved
 Prepare a flowchart
 Identify potential failure points
 Establish a time frame for operations
 Analyze profitability
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1
Facilities Layout
 The configuration of departments, work centers,
and equipment, with particular emphasis on
movement of work (customers or materials)
through the system
Product
layouts
Process
layouts
FixedPosition
layout
Combination
layouts
Adeyl Khan, Faculty, BBA, NSU
Get a good layout!
• Requires substantial
resources
• Long-term commitments
• Short-term cost/efficiency
6-19
Objective of Layout Design
Exam
 Facilitate attainment of product or service quality
 Use workers and space efficiently
 Avoid bottlenecks
 Minimize unnecessary material handling costs
 Eliminate unnecessary movement of workers or
materials
 Minimize production time or customer service time
 Design for safety
Adeyl Khan, Faculty, BBA, NSU
6-20
The Need for Layout Decisions
 Inefficient operations
 High Cost Bottlenecks
 The introduction of new products or services
 Changes in the design of products or services
 Accidents
 Safety hazards
 Changes in environmental/legal requirements
 Changes in methods and equipment
 Changes in volume of output or mix of products
 Morale problems
Adeyl Khan, Faculty, BBA, NSU
6-21
Product layout
• Layout that uses standardized processing operations to
achieve smooth, rapid, high-volume flow
• E.g. Auto plants, cafeterias
Process layout
• Layout that can handle varied processing requirements
• E.g. Tool and die shops, university departments
Fixed Position layout
• Layout in which the product or project remains stationary,
and workers, materials, and equipment are moved as
needed
• E.g. Building projects, disabled patients at hospitals
Adeyl Khan, Faculty, BBA, NSU
Combination Layouts
6-22
Figure 6.4 | Product Layout
Raw
materials
or customer
Material
and/or
labor
Station
1
Station
2
Material
and/or
labor
Material
and/or
labor
Station
3
Exam
Station
4
Finished
item
Material
and/or
labor
Used for Repetitive or Continuous Processing
Adeyl Khan, Faculty, BBA, NSU
6-23
Advantages of Product Layout
•
•
•
•
•
•
•
High rate of output
Low unit cost
Labor specialization requirement?
Low material handling cost
High utilization of labor and equipment
Established routing and scheduling
Routine accounting and purchasing
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
Adeyl Khan, Faculty, BBA, NSU
6-24
7
6
5
4
A U-Shaped Production Line
9
Workers
3
2
• Increased variation in employee
skill
• Faster/easier handling
• Close- requires less employees
• Flexibility in processing/employees
8
Advantages
Adeyl Khan, Faculty, BBA, NSU
Out
1
In
• More skill levels
• Equipment utilization rate!
10
Disadvantages
6-25
Process Layout- functional
Dept. A
Dept. C
Dept. E
Dept. B
Dept. D
Dept. F
Exam
Milling
Assembly
& Test
Grinding
Drilling
Adeyl Khan, Faculty, BBA, NSU
Used for
Intermittent
processing
Job Shop or
Batch Processes
Plating
Process Layout - work travels
to dedicated process centers
6-26
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
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
Adeyl Khan, Faculty, BBA, NSU
6-27
Fixed Position Layouts
 Layout in which the product or project remains
stationary, and workers, materials, and equipment
are moved as needed.
Optimal product
• Weight, Size, Bulk
Examples
• Large construction
projects
Adeyl Khan, Faculty, BBA, NSU
6-28
Group Technology Layout
• The grouping into part families of
items with similar design or
manufacturing characteristics.
Each cell is assigned a family for
production. This limits the
production variability inside cells,
hence allowing for a product
layout.
Part Family W
Assemble Y,W
Part Family X
Part Family Z
Assemble X,Z
Part Family Y
Final Product
Similar to cellular layout
Similar manufacturing characters
Adeyl Khan, Faculty, BBA, NSU
2
Exa
m
Process vs. Cellular Layouts
Dimension
Process
Cellular
Number of moves
between departments
many
few
Travel distances
longer
shorter
Travel paths
variable
fixed
Job waiting times
greater
shorter
Throughput time
higher
lower
Amount of work in
process
higher
lower
Supervision difficulty
higher
lower
Scheduling complexity
higher
lower
Equipment utilization
lower
higher
Adeyl Khan, Faculty, BBA, NSU
6-30
Other Layout
 Cellular Manufacturing
 Layout in which machines are grouped into a cell that
can process items that have similar processing
requirements. A product layout is visible inside each
cell.
 Combination Layouts:
combination of three pure types.
Example: hospital: process and fixed position.
Adeyl Khan, Faculty, BBA, NSU
3
Service Layouts
 Warehouse and storage layouts
 Retail layouts
 Office layouts
 Service layouts must be aesthetically pleasing as
well as functional
Adeyl Khan, Faculty, BBA, NSU
6-32
Design Product Layouts: Line Balancing
 Line Balancing is the process of assigning tasks to
workstations in such a way that the workstations
have approximately equal time requirements.
 Determine Maximum Output
 Example: If a student can answer a multiple choice
question in 2 minutes but gets a test with 30
questions and is given only 30 minutes then
 OT=30 minutes; D=30
 Desired cycle time=1 minute < 2 minutes = Cycle time
from the process capability
Adeyl Khan, Faculty, BBA, NSU
6-33
Determine Maximum Output
OT
Output rate =
CT
OT  operating time per day
D = Desired output rate
Cycle time is the maximum time
allowed at each workstation to
complete its set of tasks on a
unit.
OT
CT = cycle time =
D
Adeyl Khan, Faculty, BBA, NSU
6-34
Determine the Minimum Number
of Workstations Required: Efficiency
 Example: Students can answer a multiple choice question in 2 minutes but given a
test with 30 questions and is given only 30 minutes. What is the minimum number
of students to collaborate to answer all the questions in the exam?
 Total operation (task) time = 60 minutes = 30 x 2 minutes
 Operating time=30 minutes
 60/3=2 students must collaborate. This Nmin below.
N min
N min
Total task time for all products produced in a day (D)(  t)
=

Availabale time in a day
OT
t
t
Total task time for a product




OT/D Availabale time for a product
CT
 t = sum of task time s
Adeyl Khan, Faculty, BBA, NSU
3
Calculate Percent Idle Time
Idle time per cycle
Percent idle time =
(N)(CT)
Efficiency = 1 – Percent idle time
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6-36
Precedence Diagram | Figure 6.11
 Precedence diagram: Tool used in line balancing to
display elemental tasks and sequence requirements
3.1 min.
7.2 min.
a
b
c
2.7 min.
Adeyl Khan, Faculty, BBA, NSU
Exam
d
e
4.5 min.
10 min.
6-37
Example 1: Assembly Line Balancing
 Arrange tasks shown in Figure 6.10 into three
workstations.
 Use a cycle time of 1.0 minute
Line Balancing Rules- Heuristics
• 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.
Adeyl Khan, Faculty, BBA, NSU
6-38
0.1 min.
1.0 min.
a
b
Example 1
Solution
c
d
0.7 min.
0.5 min.
Eligible
Assign
Task
Revised
Time
Remaining
1.0
0.9
0.2
a, c
c
none
a
c
-
0.9
0.2
2
1.0
b
b
0.0
3
1.0
0.5
0.3
d
e
-
d
e
-
0.5
0.3
Workstation
1
Time
Remaining
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e
0.2 min.
Station
Idle Time
0.2
0.0
0.3
0.5
6-39
0.1 min.
1.0 min.
a
b
c
0.7 min.
Adeyl Khan, Faculty, BBA, NSU
d
0.5 min.
e
0.2 min.
6-40
Example 2 | CT = 1.2 min
0.2
0.2
0.3
a
b
e
0.8
0.6
c
d
Adeyl Khan, Faculty, BBA, NSU
f
g
h
1.0
0.4
0.3
6-41
Solution to Example 2
Station 1
a
b
Station 2
Station 3
e
f
c
Adeyl Khan, Faculty, BBA, NSU
Station 4
g
h
d
6-42
Bottleneck Workstation
1 min.
30/hr.
1 min.
30/hr.
2 min.
30/hr.
1 min.
30/hr.
Bottleneck
Adeyl Khan, Faculty, BBA, NSU
6-43
Parallel Workstations
30/hr.
1 min.
60/hr.
2 min.
30/hr.
1 min.
1 min.
60/hr.
30/hr.
2 min.
30/hr.
Parallel Workstations
Adeyl Khan, Faculty, BBA, NSU
6-44
The obstacle
 The difficulty to forming task bundles that have the
same duration.
 The difference among the elemental task lengths can
not be overcome by grouping task.
 Ex: Can you split the tasks with task times {1,2,3,4} into two
groups such that total task time in each group is the same?
 Ex: Try the above question with {1,2,2,4}
 A required technological sequence prohibit the
desirable task combinations
 Ex: Let the task times be {1,2,3,4} but suppose that the task with
time 1 can only done after the task with time 4 is completed.
Moreover task with time 3 can only done after the task with time
2 is completed. How to group?
Adeyl Khan, Faculty, BBA, NSU
4
Designing Process Layouts
Information Requirements
 List of departments- easy
 Shape requirements
 Projection of work flows- easy?
 One way vs. two way: Packaging and final assembly.
 Distance between locations- easy
 One way vs. two way: Conveyors, Elevators.
 Amount of money to be invested- easy?
 List of special considerations- easy?
 Technical, Environmental requirements
Adeyl Khan, Faculty, BBA, NSU
6-46
Example 3:
Locate 3 departments to 3 sites
 Distances: in meters
From\To
A
B
C
A
20
40
B
20
30
 Work Flow: in kilos
From\To
W1
W2
W1
20
W2 W3
10 80
30
W3
90
70
Adeyl Khan, Faculty, BBA, NSU
C
40
30
-
-
4
Example 3
 Mutual flow:
From\To
W1
W2 W3
W1
-
-
-
W2
30
-
-
W3
170 100 -
 Closeness graph:
Ranking locations & Departments
1
2
3
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4
Example 3: Interdepartmental Work
Flows for Assigned Departments
30
W
1
A
Figure 6.13
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170
100
W
3
B
W
2
C
From\To A
B
C
A
-
20
40
B
20
-
30
C
40
30
-
6-49
Designing Process Layouts
 Create Layout Alternatives
 Find the one which minimizes transportation costs
and distance traveled
Adeyl Khan, Faculty, BBA, NSU
5
Closeness Rating: multiple criteria
 Common use of facilities/equip
 Sharing of people
 Flows and sequences
 Communication considerations
 Process
 The human factor
Adeyl Khan, Faculty, BBA, NSU
5
Closeness Rating
Exam
Solution P 250
Adeyl Khan, Faculty, BBA, NSU
5
Practice Questions
 True/False
 Job-Shop systems have a lower unit cost than
continuous systems do because continuous systems
use costly specialized equipment.
 True/False
 In cellular manufacturing, machines and
equipment are grouped by (machine) type (e.g., all
grinders are grouped into a cell).
Adeyl Khan, Faculty, BBA, NSU
5
Practice Questions
 2a. Rank according to product variety- descending.
 2b. Which type of processing system tends to
produce the most product variety?

A)
Assembly

B)
Job-Shop

C)
Batch

D)
Continuous

E)
Line Balancing
Adeyl Khan, Faculty, BBA, NSU
5
Practice Questions
 3. A production line is to be designed for a job with
three tasks. The task times are 0.3 minutes, 1.4
minutes, and 0.7 minutes. The minimum cycle time
in minutes, is:

A)
0.3

B)
0.7

C)
1.4

D)
2.4

E)
0.8
Adeyl Khan, Faculty, BBA, NSU
5
Process Layout
222
444
Mill
222
111
444
111 333
111
333
Lathes
Adeyl Khan, Faculty, BBA, NSU
222
Drill
Grind
3333
1111 2222
Heat
treat
Assembly
111
Gear
cutting
111
444
6-56
-1111
Lathe
Mill
Drill
222222222
Mill
3333333333
Lathe Mill
44444444444444
Adeyl Khan, Faculty, BBA, NSU
Drill
Mill
Heat
treat
Gear
-1111
cut
Heat
treat
Grind - 2222
Heat
treat
Grind - 3333
Drill
Gear - 4444
cut
Assembly
Cellular Manufacturing Layout
6-57
Quiz: Product/Process layout?
A
B
D
C
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5
Quiz: Match?
Job Shop
Product
Project
Process
Repetitive
Fixedposition
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Linear Programming:
Very useful technique.
Adeyl Khan, Faculty, BBA, NSU
6
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.
Adeyl Khan, Faculty, BBA, NSU
6-61
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.
Adeyl Khan, Faculty, BBA, NSU
6-62
Product – Process Matrix | Figure 6.2
Process Type Job Shop
Job Shop
Batch
Repetitive
Appliance
repair
Emergency
room
Continuous
(flow)
Ineffective
Commercial
baking
Batch
Classroom
Lecture
Automotive
assembly
Repetitive
Automatic
carwash
Continuous
(flow)
Ineffective
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Steel Production
Water
purification
6-63
Product – Process Matrix | Figure 6.2
(cont’d)
Dimension Job Shop
Batch
Repetitive
Continuous
(flow)
Job variety
Very High
Moderate
Low
Very low
Process
flexibility
Very High
Moderate
Low
Very low
Unit cost
Very High
Moderate
Low
Very low
Volume of
output
Very High
Low
High
Very low
Adeyl Khan, Faculty, BBA, NSU
6-64
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