Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Shop Floor Support
Systems
Lecture 10 Topic :
Automatic Guided
Vehicles - Concepts
Segment A Topic:
ADVANCED
MANUFACTURING
SYSTEMS DESIGN
Shop Floor Support
Automated Guided Vehicles Concepts
Slide 2
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Overview
• Overview of Material Handling Systems
• Automated Guided Vehicles
–
–
–
–
–
Slide 3
Components
Types
Guidance
Routing and Control
System Design
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Material Handling
Overview (1)
• Concept
– Best Material Handling is No Material
Handling
• Except for Delivery to Customer, Material
Handling Adds No Value to Product
• Can be 10 to 80% of Cost of Product
• Goal
– Least Cost Delivery of Undamaged Material
in a Timely Manner
Slide 4
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Material Handling
Overview (2)
• In–Plant Movement
– On Machines/Equipment (NC)
– Within and/or Between Cells/Machines
•
•
•
•
•
Fixed Path (Conveyors, Robots)
Variable Path (AGVs, Forktrucks)
Interface of Handling System and Equipment
Location Information and Control System
Hoists/Assists
– Between Floor and Storage (WIP, Finished)
• Location Information, Status, and Control
Slide 5
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Material Handling
Overview (3)
• Outside of Plant Movement
– Between Suppliers, Subcontractors
• Generally Longer Distances
• Unit Loads for Efficiency
• Time Delays, Variance in Receipt Time
– Between Plant and Customer
• Generally Longer Distances
• Multiple Destinations, Amounts to Move
• Multiple Modes (Truck, Rail, Air, …)
Slide 6
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Material Handling and
Storage Principles (1)
• Orientation Principle
– Facilitate Next Operation
• Planning Principle
– Establish Plan, Contingencies
• Systems Principle
– Integrate into Rational System
• Unit Load Principle
– Always transport is Largest Load Possible
Slide 7
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Material Handling and
Storage Principles (2)
• Space Utilization Principle
– Use All (Cubic) Space
• Standardization Principle
– Maximize Similarity of Solutions
• Ergonomic Principle
– Make Human Compatible
• Energy Principle
– Minimize Energy (Potential/Kinetic)
Slide 8
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Material Handling and
Storage Principles (3)
• Ecology Principle
– Minimize Environmental Impact
• Mechanization Principle
– Mechanize Wherever Possible
• Flexibility
– Use Equipment Across Part Families
• Simplification Principle
– Eliminate/Simplify/Reduce
Slide 9
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Material Handling and
Storage Principles (4)
• Gravity Principle
– Use Gravity (Cheap!) Whenever Possible
• Safety Principle
– Meet Codes, Capture Experience
• Computerization Principle
– Use Automation Wherever Applicable
• System Flow Principle
– Integrate Data and Material Flow
Slide 10
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Material Handling and
Storage Principles (5)
• Layout Principle
– Synchronize Processing and Layout
• Cost Principle
– Investigate Alternatives
• Maintenance Principle
– Ability/Cost to Service and Maintain
• Obsolescence Principle
– Long Range Life Cycle Plan
Slide 11
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Automatic Guided Vehicles
(AGV’s)
• Concepts
– Utilization
• Idle Labor = Problem (Wait for Delivery or Wait to
Deliver)
• Idle Equipment = Cost
• Equipment Cost -> Spread over Multiple Shifts
– Control -- Sequence/Discipline
– Automatic “Knowledge” of Location
– Conveying with Less Bulk/Blockage
Slide 12
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s - Components
• Components (Same as All Mat’l Handl.)
– The Vehicle
• Device and Power System
– The Path
• Routing and Alternatives
– Control Unit
• Monitor and Control Vehicle and Path
• Collision Avoidance/Reroute
– The Computer/Info System Interface
• Link to Rest of Production System/World
Slide 13
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – Types/Guidance
• Types
–
–
–
–
–
–
Slide 14
Towing
Unit Load
Pallet Truck
Fork Truck
Light Load
Assembly Line
• Guidance
–
–
–
–
–
–
Computer Integrated
Manufacturing Systems
Wire
Optical
Inertial
Infrared
Laser
Teaching
© 2000 John W. Nazemetz
AGV’s – System Analysis (1)
• Vehicle Design and Selection
– Size/Cost/Maintenance
– Height/Load/Width/
– Maneuverability/ Interface/Off-Path
• Path/Vehicle Design Considerations
– Unidirectional, Bi-directional, Branches
– Loading/Unloading, Variety of Load
– Safety/Clearances
Slide 15
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – System Analysis (2)
• Number of Vehicles
– Analytical (p. 274 Singh)
• Single Cycle (Empty, Loaded Travel Percentage)
• Multiple Cycle (Probabilistic)
– Simulation
– Breakdown/Replacement
Slide 16
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – Analysis (1)
• Path
–
–
–
–
Slide 17
Routing/Flow of Product
Type of Guidepath/Vehicle
Location of Pickup/Dropoff Points
Storage/Buffer Locations
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – Analysis (2)
• Number of Vehicles
– Distances Between Points
– To/From Volume Between Points
• Recycling/Returns
• Alternate Branches
–
–
–
–
–
Slide 18
Required Deliveries/Hour
Loading and Unloading Time
Vehicle Travel Speed
Traffic Factor
Operation concept (Single/Bi-Directional –
One Cart per Path Segment)
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – Example
•
Slide 19
Will Show Next Segment
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Lecture 10 Topic : Shop Floor Support
Systems
Segment A Topic: Automated Guided
Vehicles - Concepts
END OF SEGMENT
Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Lecture 10 Topic : Shop Floor Support
Systems
Segment B Topic: Automated Guided
Vehicles – Example, ASRS Systems
ADVANCED
MANUFACTURING
SYSTEMS DESIGN
Shop Floor Support
Automated Guided Vehicles –
Example
Automated Storage and Retrieval
Slide 22
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Overview
• AGV Design Example
• Automated Storage and Retrieval
Systems
– Principles and Concepts
– Design and Analysis
• AGV and ASRS Rationalization
Slide 23
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – Example Def’n
• Primarily “Straight Line” Flow with
Rework Returns
• Routing
– Whse -> A -> B -> C -> D -> Whse
– A and B are Machining
– C and D are Assembly
• Load
– 100 Units Per Hour
Slide 24
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – Example Layout
A
B
C
Warehouse
Slide 25
D
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – Example Flows (1)
A
100
B
10
8
100
50
100
Warehouse
Slide 26
100
C
150
12
D
150
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – Example Volumes
.
From
To
.
A
B
C
D
50
100
Whse
100
A
-
100
B
10
-
100
8
-
150
12
-
C
D
Slide 27
Computer Integrated
Manufacturing Systems
Whse
150
© 2000 John W. Nazemetz
AGV’s – Assumed Path
100
B
100
A
C
Warehouse
D
Slide 28
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – Path Volumes
(Unidirectional)
.
To
From
.
A
B
C
D
Whse
50
100
Whse
100
A
-
100
B
10
-
100
8
-
150
12
-
C
D
W -> A
(110)+8+(50+12)+(100)=280
150
0
A -> B
0+108+62+100=272
8
B -> C
10+0+162+100 = 272
8
C -> D
10+8+(100+150) = 268
D -> W
10+8+12+150 = 180
Slide 29
Computer Integrated
Manufacturing Systems
12
100
© 2000 John W. Nazemetz
AGV’s – Path Volumes
(Bi-directional)
.
To
From
.
A
B
C
D
50
100
Whse
Whse
100
A
-
100
B
10
-
100
8
-
150
12
-
150
C
D
W <-> A
(100)+ (0) + (50) + (100)
= 250
+12
A <-> B
10+ (100) + (50) + (100)
= 260 +10
+2
B <-> C
0 + 8+ (50+100) + (100)
= 258 + 8
+4
C <-> D
0 + 0 + 12+ (100+150 )
= 262 +12 *
D <-> W
0+0+0+0+ 150
= 150
Slide 30
Computer Integrated
Manufacturing Systems
+ 112
© 2000 John W. Nazemetz
AGV’s – Analysis
• Measure of Performance
– Number of Vehicles Needed
Ndeliveries / hour
Nvehicles 
60Tf
Dd
De
 Th 
v
v
Slide 31
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
AGV’s – Sensitivity
• Different Paths
– Dedicated Loops
– Different Equipment Positions
– Different Vehicles
• Loads/Speeds
– Different Traffic Factors
• Higher for Bi-directional, Larger Segments
– Breakdowns
Slide 32
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Automatic Storage And
Retrieval Systems (1)
• Concepts
–
–
–
–
–
–
Space Efficiency
Utility Savings (Lights, Heat, ...)
Knowledge of Location
Safety (Elimination of Labor)
Zoned Storage
Distributed/Multiple Locations of Items
• Breakdown of System
• Rsponse Time
– Less Breakage, Pilferage
Slide 33
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Automatic Storage And
Retrieval Systems (2)
• Terminology
– Storage Volume/Cube
• Space of Warehouse
– Bay
• Vertical Column of Storage Locations
– Row
• Series of Bays (One Side of Aisle)
– Aisle
• Space Between Rows
Slide 34
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Automatic Storage And
Retrieval Systems (3)
• Terminology
– Storage Racks
• Structure comprising storage locations, bays, and
rows
– Storage/Retrieval Unit
• Machine capable of storing/retrieving items from
storage locations
– Input Output Stations
• Area/Equipment at end of aisles that interfaces
with factory floor distribution and receiving
system
Slide 35
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Automatic Storage And
Retrieval Systems (4)
• Terminology
– Storage Modules/Bins
• Media for holding parts in a storage location
– Pick-up and Delivery Stations
• Same as Input-Output Stations
– Transfer Stations
• End of Aisle Equipment Used to effect transfer of
parts between rows (Same as Pick-up and
Delivery/Input-Output Stations)
Slide 36
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Automatic Storage And
Retrieval Systems (5)
• Why Use ?
– Space Efficiency (Height/Cube)
• No Need to Allocate Space so Human can
Remember Location/Find
– Improved Inventory Management
• Accuracy of Counts
• Knowledge of Location(s)
• Aging/Security
– Quick Storage/Retrieval
– Eliminate Manual Operations
– Interface with Other Automated Systems
Slide 37
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Automatic Storage And
Retrieval Systems (6)
• Types
– Unit Load
– Mini-Load
• Location Precision
• Must be in Trays, Standard Containers
– Person on Board
• Kitting
• Small Items
– Deep Lane
– Automated Item
Slide 38
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Automatic Storage And
Retrieval Systems (7)
• Design, Modeling, and Analysis
– Minimize Number of Spaces
• Dedicated Storage
– Contamination/Special Requirements
• “Random” Storage
– Rules applied so not Totally random
– Maximize Throughput/$
• Single Cycle
• Dual Cycle
• Number of Aisles vs. Response Time
Slide 39
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
ASRS Design (1)
• Determine Load/Storage Bin Sizes
– Distribution of Sizes (Unit Multiples)
• Determine Number of Each Size Needed
– Dedicated
• Sum of Maximum Needed in Any Period
– Random
• Maximum Aggregate, Any Period
Slide 40
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
ASRS Design (2)
• Determine Number of Store/Retrieve
Needed per Hour
• Determine Number/Length of Rows and
Bays
– Base on Random or Dedicated Storage
– Available Footprint Restrictions
– Common Sense
• Maximum Practical Length
– Cycle Time
– Available Height
Slide 41
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
ASRS Design (3)
• Determine Cycle Times
– Dependant on
• Aisle Length/Height, Ratio
• Size/Number of Storage Locations
• S/R Speed
– Single Cycle
• Only Stores or Only Retrieves per cycle
– Dual Cycle
• Stores and Retrieves (after store) each cycle
Slide 42
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
ASRS Design (4)
• Determine Cycle Times
L  n(l  c 2)
H  m(h  c1)
where
n  number _ of _ bays
m  number _ of _ storage _ space / height
Slide 43
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
ASRS Design (5)
• Determine Cycle Times
t h  L / Vh
t v  H / Vv
where
Vh  Horizontal _ Velocity
Vv  Vertical _ Velocity
Slide 44
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
ASRS Design (6)
• Determine Cycle Times
2
Q
Tsc  T (
 1)  2Tpd
3
Where
T  max( th, tv )
Q  min( th / T , tv / T )
Tpd  Time _ for _ Pickup _ or _ Deposit
Slide 45
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
ASRS Design (7)
• Determine Cycle Times
T
2
3
Tdc  (40  15Q  Q )  4Tpd
30
Where
T  max( th, tv )
Q  min( th / T , tv / T )
Tpd  Time _ for _ Pickup _ or _ Deposit
Slide 46
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
ASRS Design (8)
• Assess Alternatives
– Vary Length/Height
– Vary Single/Dual Command Cycles/Ratio
– Calculate System Cost for Various
Configurations
– Select “Best”
• Expandability
• Match to Other Automated Systems
Slide 47
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Shop Floor Support
Systems
Lecture 10 Topic :
AGV Example and
ASRS
Segment B Topic:
END OF SEGMENT
Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Shop Floor Support
Systems
Lecture 10 Topic :
Segment C Topic:
Quality Assurance
ADVANCED
MANUFACTURING
SYSTEMS DESIGN
Shop Floor Support
Quality Assurance/Engineering
Slide 50
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Overview
• Defining Quality
– Meaning
– Dimensions
– Costs
•
•
•
•
Taguchi Loss Function
Failure Mode and Analysis
Control Charts
Anticipatory Quality Control
Slide 51
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Defining Quality
• “The totality of features and
characteristics of a product or service
that bear on its ability to satisfy a given
need”
ANSI/ASQC Standard A3-1987
Slide 52
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Dimensions of Quality (1)
• Dimensions (All Products Subsets of)
– Performance
• Job it Does
– Features
• Secondary Characteristics
– Time
• Time to Receive/Time to Use
– Reliability
• Meant Time to Failure
Slide 53
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Dimensions of Quality (2)
• Dimensions (All Products Subsets of)
– Durability
• Amount of (Ab)Use to Maintenance or Repair
– Uniformity
• Variation between Instances
– Consistency/Accuracy
• Specifications Conformance
– Serviceability
• Response to Complaints/Ability for Owner Service
Slide 54
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Dimensions of Quality (3)
• Dimensions (All Products Subsets of)
– Aesthetics
• Psychological/Sensual Appeal
– Personal Interface
• People to People Interaction Quality
– Harmlessness
• To User, To Environment
– Perceived Quality
• Purchaser Perception/Inference
Slide 55
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Costs of Quality (1)
• Prevention Costs
– Avoiding Costs of Failure/Degraded
Performance
• Appraisal Costs
– Cost of Measurement/Testing to Assure
Quality
• Internal Failure Costs
– Cost of Scrapping/Repairing Defects prior to
Customer Receipt of Product
Slide 56
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Costs of Quality (2)
External Failure Costs
– Cost of Repairing/Replacing Defects after
Customer Receipt of Produc t
– Suits for Damages as a Result of Lack of
Merchantability
• Life Cycle Costs
–
–
–
–
Slide 57
Designing Quality In Products, Processes
Quality Production
Quality Maintenance/Repair
Disposal
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Taguchi Loss Function (1)
• Concept
– Loss increases with deviation from Target
Value (Quadratically)
– Nominal is Best:
L( y )  k ( y  T ) 2
Where
k  quality _ Loss _ coefficient
y  quality _ characteristics _ of _ product
T  targe t _ value
Slide 58
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Taguchi Loss Function (2)
• Concept
– Loss increases with deviation from Target
Value (Quadratically)
– Smaller is Better:
L( y )  k ( y ) 2
Where
k  quality _ Loss _ coefficient
y  quality _ characteristics _ of _ product
T  targe t _ value
Slide 59
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Taguchi Loss Function (3)
• Concept
– Loss increases with deviation from Target
Value (Quadratically)
– Larger is Better:
1
L( y )  k ( 2 )
y
Where
k  quality _ Loss _ coefficient
y  quality _ characteristics _ of _ product
T  targe t _ value
Slide 60
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Taguchi Loss Function (4)
• Concept
– Average Loss can be Determined Based on
Target, Functional Limits, and Variation
– Based on Average Loss
• Different Processes can be Evaluated
• Different Definitions of Functional Limits can be
Explored
– Controllable, Uncontrollable, Noise Factors
Slide 61
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Failure Mode Analysis
• Concept
– Recognize and evaluate potential failure
modes and effects
• Mode -- Occurrence/Severity/Detection
– Identify actions that can eliminate or reduce
the chance of potential failure occurring
– Document the process
Slide 62
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Control Charts (1)
• Attributes
– X bar and R
– P charts
• Use to Identify Unlikely Events
– Presume Process Has Changed
Slide 63
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Control Charts (2)
• Record Out-of-Control Events/Causes
–
–
–
–
Slide 64
Histograms
Pareto Charts
Cause and Effect Diagrams
Scatter Diagram
Computer Integrated
Manufacturing Systems
© 2000 John W. Nazemetz
Anticipatory Quality
Control
• “Look Ahead Control Charts”
– Results not Random, Autocorrelated
UCL
Mean
LCL
Slide 65
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Computer Integrated
Manufacturing Systems
x
x
x
x
x
© 2000 John W. Nazemetz
Advanced Manufacturing Systems
Design
© 2000 John W. Nazemetz
Shop Floor Support
Systems
Lecture 10 Topic :
Segment C Topic:
Quality Assurance
END OF SEGMENT