Transcript Lecture Slides

Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Concurrent
Engineering
Lecture 3 Topic :
Introduction to
Simultaneous and Asynchronous
Engineering
Segment A Topic:
ADVANCED
MANUFACTURING
SYSTEMS DESIGN
Concurrent Engineering
Introduction to Simultaneous and
Asynchronous Engineering
Activities
Slide 2
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Overview
• Concurrent Engineering
– Definition
– Concepts
– New Products
– Existing Products
Slide 3
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Computer Integrated
Manufacturing Systems
• Definition Revisited
• Systems which enable the integrated,
rationalized design, development,
implementation, operation and
improvement of production facilities
and their output over the life cycle of
the product. These systems identify and
use appropriate technology to achieve
their goals at minimum cost and effort.
Slide 4
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Concurrent Engineering -Definition
• Concurrent Engineering is a systematic
approach to the integrated, concurrent
design of products and their related
processes, including manufacturing and
support. This approach is intended to
cause the developers, from the outset,
to consider all elements of the product
life cycle from conception to disposal,
including quality, cost, schedule, and
user requirements. (Pennell and Winner,
1989)
Slide 5
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Concurrent Engineering Definition Problems
• Name Implies only Engineering Involved
• Activity is Really Concurrent (DESIGN)
CONCEPTUALIZATION and EVALUATION
(ENGINEERING)
– Require Broad View of Design
– Must Assure that Correct Concepts Are
Incorporated into the Design
– Must Assure that Principles of
Engineering/Nature are Followed
Slide 6
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Goals of Concurrent
Engineering in CIM (1)
• Primary Goal is to Assure
Rationalization in Early Stages to Avoid
Cost/Improve Product
–
–
–
–
–
Slide 7
Operational Concept
Physical Concept
Manufacturing Concept
Maintenance Concept
Disposal Concept
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Goals of Concurrent
Engineering in CIM (2)
• Secondary Goal is Lead Time Reduction
– Administrative Lead Time
• Design and Rationalization of Product
• Approval and Acquisition of Facilities
– Manufacturing Lead Time
• Scheduling and Execution
• Storage and Distribution
• Measure of Exposure to Risk/Changes
Slide 8
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Traditional Process of
Serial Engineering
•
•
•
•
•
•
•
Functions Separated
Functions Serially Executed
No Interaction
Maintenance Usually an Afterthought
Time Consuming
Costly
Product a Series of Suboptimal
Reconsiderations
Slide 9
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Serial Engineering
SUPPORT??
DESIGN
Slide 10
MANUFACTURING
PLANNING
MANUFACTURING
Computer Integrated
Manufacturing Systems
CUSTOMER
© 2000 John W. Nazemetz
Concurrent vs. Serial
Engineering
•
•
•
•
All Viewpoints Solicited
Interdisciplinary Teams
Life Cycle Cost Considered
Attempt to Embody Concept Early Before Committing to Detail Design
• Data/Information/Knowledge Exchange
Planned and Encouraged
• Cycle Time and Cost Reduced
Slide 11
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
A Concurrent Engineering
Model
PRODUCT
FUNCTIONAL
CONCEPT
PRODUCT
MANUFACTURING
CONCEPT
DISCIPLINE INPUTS
• ENGINEERING
CONCURRENT
DESIGN
• PRODUCTION
• CUSTOMERS
• WORKERS
PRODUCT
MAINTENENCE
CONCEPT
Slide 12
• MARKETING
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Virtual Concurrent
Engineering
• Always a Virtual Endeavor
– Groups Are Always Geographically (and
Culturally) Distributed
• How Far is Too Far Apart?
– Information Generated/Stored in Various
Formats and Locations
• Single Plant + Customers
• Multiple Plants (Same Organization) + Customers
• Multiple Organizations + Customers
Slide 13
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Keys to Concurrent
Engineering
• Supportive Culture
• Clear Understanding and
Documentation of Requirements
• Technical Competence/Experiences
• Technical Tool Availability (CAx Tools)
• Communication Competence
• Communication and Information Tool
Availability
Slide 14
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Concurrent
Engineering
Segment A Topic: Introduction to
Simultaneous and Asynchronous
Engineering
Lecture 3 Topic :
END OF SEGMENT
Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Concurrent
Engineering
Lecture 3 Topic :
Computer Aided
Process Planning
Segment B Topic:
Overview
• Computer Aided Process Planning
– The Use of Computer To Develop and
Analyze Alternative Manufacturing
Processes
– Part of Design
Slide 17
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Computer Aided Process
Planning
• Definition
– Use of computer and information
technologies to assist in the cost effective
development and assessment of alternative
methods of production and sequences for a
specific product specification and
identification of areas for potential
improvement in specifications from the
process/manufacturing viewpoint.
Slide 18
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Manufacturing Processes
•
•
•
•
Casting and Molding Processes
Forming Processes
Chip Formation Processes
Finishing Processes
– Small Chip Removal Processes
– Treatment (Mechanical and Chemical)
Processes
– Coating Processes
Slide 19
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Manufacturing Process
Review
• How To Determine Process/Cost
– Process To Be Used (Shape)
– Process Ability to Hold Dimensional
Tolerance
– Surface Finish (How Determined)
– Set Up Times
– Machining Parameter
Selection/Specification
– Part Processing Times
– Cost Optimization
Slide 20
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Knowledge Requirements
for Process Planning
• Manufacturing Processes/Capabilities
• Design Specification/Process
Interaction
• Machine Tool Options/Capabilities
• Tool and Tooling Options
• Capacity Availability
• Real and Accounting Costs of
Manufacture
• Cost - Volume Life Cycle Relationships
Computer Integrated
Slide 21
© 2000 John W. Nazemetz
Manufacturing Systems
• Actual Floor Operations
Types of Process Planning
• Manual Process Planning
• Variant Process Planning
– Existing Plan Retrieval
– Composite (Master) Part Plans
• Generative Process Planning
– Computer Generated Process Plans
– Use of Artificial Intelligence
Slide 22
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Manual Process Planning
•
•
•
•
Study Design and Specifications
Recall Past Relevant Experiences
Discuss “Tight” Specifications
Develop Alternative Process Sequences
– Specification/Capabilities
– Volume/Tooling/Cost Requirements
– Capacity Availability
• Select and Document “Best” Process
• Implement and Monitor
Slide 23
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Manual Process Planning Drawbacks
• Completely Dependant on Experience of
Process Planner
• Number of Alternatives Generated
Limited
• Relatively Slow Process
• Documentation Usually Poor
• Incorporation of Past Investment in
Process Design not Assured
Slide 24
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Variant Process Planning
• Identify/Find “Similar” Parts
• Compare Existing Parts with Current
• Delete Unneeded Part Features in
Retrieved Part
• Add Part Features/Process Not in
Retrieved Part
• Add “New” Design into System for Later
Use
Slide 25
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Variant Process Planning Retrieval Systems
• System for Associating/Locating Past
Process Plans/Designs Crucial to
Success
– Group Technology Based Systems
• As Up Front Design Philosophy to Limit Variation
• As “Key” to Access Previous Plans
– Part Features
– Process Sequence Based Systems
– Problem of Pattern Recognition
Slide 26
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Variant Process Planning Composite (Master) Parts
• Develop Composite Part
– Defines Characteristics of a “Class” of Parts
– Contains all Possible Features that Can Be
Incorporated in the Design of Parts in this
Class
– Generally Defined Parametrically
• Not All CAD Systems Support Parametric Features
• Manual Intervention Required in Non-Parametric
CAD Systems
– Generally Assumes Infinite Capacity
Slide 27
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Variant Process Planning Drawbacks
• New Process Plan is Generally No Better
Than Retrieved Design
• Use of Archived Plan Does Not Always
Reflect Current Situation
• Part Family Formation is “Natural”
Fallout
• No New Technologies are Considered in
Planning
Slide 28
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Generative Process Planning
• Part Specification (CAD Model)
• Recognize Part Features From CAD
Model
• Generate Feasible Methods for
Production of Part Features
• Evaluate Operational Feasibility
• Evaluate Economics of Alternatives
• Specify Process
• Regenerate Each Time Part is Produced
Slide 29
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Generative Process
Planning (2)
• Part Specification (CAD Model)
– Must Conform to Standard
– Current Standards not Unambiguous
• Recognize Part Features From CAD
Model
–
–
–
–
Slide 30
Lines, Arcs => Surfaces
Surfaces => Part Features
Part Features Have Specifications
Recognize Relations Between Part Features
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Generative Process
Planning (3)
• Generate Feasible Methods for
Production of Part Features
– All Technically Feasible Methods Considered
– Alternate Sequences Considered
• Evaluate Operational Feasibility
– Map Technically Feasible Methods Against
Those Available to Company
– Subcontracting Difficult to Incorporate
– Tooling Difficult to Incorporate
Slide 31
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Generative Process
Planning (4)
• Evaluate Economics of Alternatives
– For this Part
– For this Part and Existing Similar Parts
– For this Part, Existing, and Contemplated
Parts
• Specify Process
• Regenerate Each Time Part is Produced
– Incorporates Temporal Information
– Increased Variation ???
Slide 32
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Generative Process
Planning - Drawbacks
• Part Feature Recognition is Not a
Mature Technology
– CAD Model Data Exchange (Precision,
Format)
– May Depend on “Missing” Material
• Expensive (Artificial Intelligence)
• Must Be Tailored to Specific Firm
• Incorporation of Proprietary Processes
Difficult
Slide 33
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Concurrent
Engineering
Lecture 3 Topic :
Computer Aided
Process Planning
END OF SEGMENT
Segment B Topic:
Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Concurrent
Engineering
Lecture 3 Topic :
Segment C Topic:
Quantitative Analysis
ADVANCED
MANUFACTURING
SYSTEMS DESIGN
Concurrent Engineering
Quantitative Analysis
Slide 36
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Overview
• Quantitative Analysis in Concurrent
Engineering
– Singh’s Mathematical Model
– Uses Manufacturing Method/Process
Capabilities, Tolerance Limits, Input and
Processing Costs, and Time Estimates to
Compare Alternatives
– Source: Singh, Nanua, Systems Approach to Computer
Integrated Design and Manufacturing, John Wiley and
Sons, Inc., New York, New York, c1995
Slide 37
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Singh’s Quantitative
Analysis (Eq. 4.1, 4.2)
• Tolerance
Alternatives and
Process Capabilities
– Standard Normal
Variate of upper
Tolerance
– Standard Normal
Variate of lower
Tolerance
Slide 38
t
t
u
k
l
k
j
j
j
j
 Z ujk
 Z ljk
t = tolerance limit
k= tolerance system (design alt.)
j= machining system
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Singh’s Quantitative
Analysis (Eq. 4.3)
i
jk
o
jk
Y ,Y ,Y
s
jk
=
output, input, scrap units
• SCrap Fraction
SC
Slide 39

jk
Y
Y
s
jk
i
jk
 ( Z )  [1  ( Z )]
l
jk
Computer Integrated
Manufacturing Systems
u
jk
© 2000 John W. Nazemetz
Singh’s Quantitative
Analysis (Eq. 4.4)
i
jk
o
jk
Y ,Y ,Y
s
jk
=
output, input, scrap units
• Mass Balance
Y  Y Y
i
jk
Slide 40
o
jk
s
jk
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Singh’s Quantitative
Analysis (Eq. 4.5, 4.6)
i
jk
o
jk
Y ,Y ,Y
s
jk
=
output, input, scrap units
• Technological Coefficients (input per
unit of output, scrap per unit of output)
k
Slide 41
i
jk

Y
Y
i
jk
o
jk
k
Computer Integrated
Manufacturing Systems
s
jk

Y
Y
s
jk
o
jk
© 2000 John W. Nazemetz
Singh’s Quantitative
Analysis (Eq. 4.7)
• Combining (Percent Acceptable in
Output Stream)
k 
s
jk
Y
Y
s
jk
o
jk

i
jk
SC jk
1  SC jk
o
jk
Y ,Y ,Y
Slide 42
s
jk

=
( Z )  [1  ( Z )]
l
jk
u
jk
( Z )  ( Z )
u
jk
l
jk
output, input, scrap units
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Singh’s Quantitative
Analysis (Eq. 4.8)
• Combining (Ratio of Input to Output
Obtained – Will be >1)
Y
i
jk
o
jk
1
k 
 1 k 
u
l
Y
( Z jk )  ( Z jk )
i
jk
i
jk
s
jk
o
jk
Y ,Y ,Y
Slide 43
s
jk
=
output, input, scrap units
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Singh’s Quantitative
Analysis (Eq. 4.4, 4.9, 4.10)
• Combining to Reform Material Balance
Equations
Y  Y Y
i
jk
o
jk
i
jk
o
jk
Y ,Y ,Y
Slide 44
s
jk
=
s
jk
Y k Y
o
jk
Y k Y
o
jk
s
jk
i
jk
s
jk
i
jk
output, input, scrap units
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Singh’s Quantitative
Analysis (Eq. 4.11)
• Cost Equation (Cost of Output and Scrap
= Cost of Input and Processing
X Y  X Y  X Y  Y f (Y )
o
jk
o
jk
s
jk
s
jk
X ,X ,X 
i
jk
o
jk
s
jk
f (Y ) 
i
jk
Slide 45
i
jk
i
jk
i
jk
i
jk
Unit Cost of input, output,scrap
Processing Cost per Unit
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
•
Singh’s Quantitative
Analysis (Eq. 4.11)
o
Dividing by Y to get output cost/unit
jk
X Y X Y
o
jk
o
jk
s
jk
Y
X
Slide 46
o
jk
s
jk
o
jk

Y
Y
i
jk
o
jk

X 
i
jk
X Y  Y f (Y )
i
jk
i
jk
i
jk
Y
Y
Y
s
jk
o
jk
X 
Computer Integrated
Manufacturing Systems
s
jk
i
jk
o
jk
Y
Y
i
jk
o
jk
fY
i
jk
© 2000 John W. Nazemetz
Singh’s Quantitative
Analysis (Eq. 4.12)
• Or, by substituting technological
factors, unit cost of output (good units)
X  k X  k X  k f (Y )
o
jk
Slide 47
i
jk
i
jk
s
jk
s
jk
Computer Integrated
Manufacturing Systems
i
jk
i
jk
© 2000 John W. Nazemetz
Singh’s Quantitative
Analysis (Eq. 4.13)
• Developing an expression for
Manufacturing Lead Time:
Tj  S j  t j k Y
i
jk
tj 
o
jk
Processing time, j th method
S j  Set-up Time
Slide 48
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Using Singh’s Quantitative
Analysis
• Given a Set of Production Methods
–
–
–
–
With Process Capabilities,
Unit Production Cost Estimates,
Unit Production Time Estimates, and
Set up Times
• and a Set of Precision Alternatives,
– Assuming Precision is Relevant to Customer
Definition of Quality
• Then, Quantitative Assessment Possible.
Slide 49
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Problems with Singh
Quantification (1)
• Product Manufacturing Centric
Viewpoint
– No Design Cost Data
– No Service/Maintenance Cost Data
– No Value to Increase/Decrease in Lead Time
• No Administrative Lead Time Factor
• No Material/Capacity Lead Time
Slide 50
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Problems with Singh
Quantification (2)
• Product Manufacturing Centric
Viewpoint
– Scrap Defined by Designer, not Customer,
no Customer Definition of Quality
– No Differential Cost Savings/Cost (Serial vs.
Concurrent)
– NOT AN ANALYSIS OF CONCURRENT
ENGINEERING !!! -- IT IS A
DESIGN/PROCESS COMPARISION
METHOD
Slide 51
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Benefits of Quantification
• Forces Focus upon Measurable Factors
– To Extent These are the “Right” Factors,
Drives Organization’s Direction
• Shows Changes/Provides Basis for
Comparison of Alternatives
Slide 52
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Concurrent ReEngineering
of Products
• No Real Difference in Organization and
Process Execution
• Only Change is Inclusion of Existing
Plant and Facilities
• Cost (Current) Known, Not Estimated
Slide 53
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Concurrent
Engineering
Lecture 3 Topic :
Segment C Topic:
Quantitative Analysis
END OF SEGMENT