Description
Layout Strategy - Operations Management
McDonald’s - New Kitchen Layout
? Fifth major innovation - kitchen design
? ? ? ?
Layout Strategy
? ? ? ?
No food prepared ahead except patty Elimination of some steps, shortening of others New bun toasting machine (11 seconds vs 30 seconds) Repositioning condiment containers ( p g (one motion, not two) ) Sandwiches assembled in order Production levels controlled by computer Discard only meat when sandwiches do not sell fast enough Savings of $100,000,000 per year in food costs
McDonald’s - New Kitchen Layout
?No food prepared ahead except patty ?Elimination of some steps, shortening of others ?New bun toasting machine (11 seconds vs 30 seconds) ?Repositioning condiment containers (one motion, not two)
Innovation at McDonald’s
? Indoor seating (1950’s) ? Drive-through window (1970s) ? Adding breakfast to the menu (1980s) ? Adding play areas (1990s) (three out of the four are layout decisions)
What is Facility Layout
? Location or arrangement of everything within & around buildings
?
Functional Lay out
Objectives are to maximize
? ? ? ?
Customer satisfaction Utilization of space, equipment, & people Efficient flow of information, material, & people Employee morale & safety
? Savings of upto 30% of manufacturing (incl. inventory) costs possible by using proper layout
Functional Lay Out – Machines with Similar Functions Grouped Together
A Product Layout
In
Cellular Lay Out
Out
Each cell processes a family of products with similar sequence of operations
Six Layout Strategies
? Fixed-position layout
?
Six Layout Strategies - continued
? Retail/service layout
?
large bulky projects such as ships and buildings deals with low-volume high-variety production (“job low volume, high variety ( job shop”, intermittent production) positions workers, their equipment, and spaces/offices to provide for movement of information
? Process-oriented layout
?
allocates shelf space and responds to customer behavior addresses t d ff b t dd trade-offs between space and materiall d t i handling seeks the best personnel and machine use in repetitive or continuous production
? Warehouse layout
?
? Office layout
?
? Product-oriented layout
?
Layout Strategies
Project
(fixed-position)
FixedFixed-Position Layout
Repetitive /Continuous
(productoriented)
Job Shop
(Processoriented)
Office
Retail
Warehouse
(storage)
Examples
Ingal Ship Building Corp. Trump Plaza
Pittsburgh Airport
Shouldice Hospital Olive Garden
Allstate Insurance Microsoft
Kroger’s Supermarket Walgreens Bloomingdales
Federal-Mogul’s Warehouse The Gap’s distribution center
Sony’s TV Assembly Line Dodge Caravans Minivans Equalize the task time at each workstation
? Design is for stationary project ? Workers and equipment come to site ? Complicating factors
Limited space at site Changing material needs- at each stage of project ? Dynamic volumes at each stage
? ?
Problem
Move material to the limited storage areas around the site Manage varied Locate workers material flow for requiring each product frequent contact close to each other Expose customer to high-margin items Balance lowcost storage with low-cost material handling
ProcessProcess-Oriented Layout
? Design places departments with large flows of material or people together p g processes ? Department areas having similar p located in close proximity
?
Emergency Room Layout
E.R.Triage room
Patient A broken leg Patient B - erratic pacemaker
Hallway
e.g., All x-ray machines in same area
? Used with process-focused processes
E.R. beds Pharmacy Billing/exit
Steps in Developing a ProcessProcess-Oriented Layout
1 Construct a “from-to matrix” 2 Determine space requirements for each department p g 3 Develop an initial schematic diagram 4 Determine the cost of this layout 5 By trial-and-error (or more sophisticated means), try to improve the initial layout 6 Prepare a detailed plan that evaluates factors in addition to transportation cost
Cost of Process-Oriented Layout ProcessMinimize cost = ?? X ij C ij
i =1 j=1 n n
where n = total number of work centers or departments i, j = individual departments X ij = number of loads moved from department i to department j C ij = cost to move a load between department i and department j
Interdepartmental Flow of Parts
1 1 2 3 4 5 6 2 3 4 5 6
Interdepartmental Flow Graph Showing Number of Weekly Loads
100
1
50
100 30
0 50 20
0 10 0 50
20 0 100 0 0
4
50
2
30
3
100 10 50
5 6
Possible Layout 1
Room 1 Assembly Department (1) Receiving Department (4) Room 4 Room 2 Printing Department (2) Shipping Department (5) Room 5 60’ Room 2 Machine Shop Department (3) Testing Department (6) Room 6 40’
Interdepartmental Flow Graph Showing Number of Weekly Loads
30
1
50
2
100
3
100
4
50
5
6
Possible Layout 3
Room 1 Painting Department (2) Receiving Department (4) Room 4 Room 2 Assembly Department (1) Shipping Department (5) Room 5 60’ Room 2 Machine Shop Department (3) Testing Department (6) Room 6 40’
Computer Programs to Assist in Layout
? CRAFT ? SPACECRAFT ? CRAFT 3-D ? MULTIPLE ? CORELAP ? ALDEP ? COFAD ? FADES - expert system
OutOut-Patient Hospital Example
CRAFT
Legend: A = xray/MRI rooms B = laboratories C = admissions D = exam rooms E = operating rooms F = recovery rooms
Office Layout
5 B B E 6 B B E
1 1 A 2 A 3 D 4 C 5 F 6 E
2 A A D
3 A A D
4 A A D
5 B B D
6 B B D
1 1 D 2 D 3 D
2 D D D
3 D D D
4 D D E
? Design positions people, equipment, & offices for maximum information flow ? Arranged by process or product
?
Example: Payroll dept. is by p p y p y process
C D D D D F F F F D E E E E D
4 C C D E E F 5 A A A A A F 6 A A A F F F
Total cost: 14,390 Est. Cost Reduction 70. Iteration 3
? Relationship chart used ? Examples
? ?
Total cost: 20,100 Est. Cost Reduction .00 Iteration 0
Insurance company Software company
Office Layout Floor Plan
1 President 2 Costing
Relationship Chart
1
O A 3 Engineering O 4 President’s Secretary
I = Important U = Unimportant
Finance Manager
Accounting
Fin. Acct.
2
U I
3
A
Ordinary closeness: President (1) & Costing (2)
4
Brand X
Absolutely necessary: President (1) & Secretary (4)
Office Relationship Shart
1 President 2 Chief Technology Officer 3 Engineer’s Area 4 Secretary y 5 Office entrance 7 Equipment cabinet 8 Photocopy equipment 9 Storage room 9 Storage room O A O A U I I
Val. Closeness
Retail/Service Layout
Absolutely necessary Especially p y important Important Ordinary OK Unimportant Not desirable
A I I
I U O O A E U O X E E U U A O O U I O X U A E E I
I
A E I O U X
? Design maximizes product exposure to customers ? Decision variables
? ?
Store flow pattern Allocation of (shelf) space to products Video
? Types
Grid design ? Free-flow design
?
Retail Layouts Some Rules of Thumb
? Locate high-draw items around the periphery of the store ? Use prominent locations such as the first or last aisle for high-impulse and high margin items ? Remove crossover aisles that allow customers the opportunity to move between aisles ? Distribute what are known in the trade as “power items” (items that may dominate a shopping trip) to both sides of an aisle, and disperse them to increase the viewing of other items ? Use end aisle locations because they have a very high exposure rate
Retail /Service Layout Grid Design
Grocery Store
Bread
Milk
Meat
Produce Frozen Foods
Office
Carts
CheckCheckout
Store Layout - with Dairy, Bread, High Drawer Items in Corners
Retail/Service Layout FreeFree-Flow Design
Apparel Store Feature Trans. Counter Display Table
Retail Store Shelf Space Planogram
? Computerized tool for shelf-space management ? Generated from store’s scanner data on sales ? Often supplied by manufacturer ? Example: P&G
PERT PERT PERT PERT PERT
Warehouse Layout
5 facings
VO-5
VO-5
VO-5
SUAVE
SUAVE
? Design balances space (cube) utilization & handling cost ? Similar to process layout ? Items moved between dock & various storage areas ? Optimum layout depends on
Variety of items stored ? Number of items picked
?
VO-5 VO-5
2 ft. ft.
Warehouse Layout Floor Plan
Conveyor
Truck
?
Cross Docking
? Transferring goods
from incoming trucks at receiving docks ? to outgoing trucks at shipping docks
InIncoming
Outgoing
Zones
Order Picker
? Avoids placing goods into storage ? Requires suppliers provide effective addressing (bar codes) and packaging that provides for rapid transhipment
Random Stocking Systems Often:
? Maintain a list of “open” locations ? Maintain accurate records of existing inventory and its locations ? Sequence items on orders to minimize travel time required to pick orders ? Combine orders to reduce picking time ? Assign certain items or classes of items, such as high usage items, to particular warehouse areas so that distance traveled is minimized
An Assembly Line Layout
Repetitive Layout
Work
Assembly Line Balancing
(Design of Product Layout) Work Station
1
Station
3
4
Work Station
2
5
Belt Conveyor
? Analysis of production lines :for required volumes ? Nearly equally divides work between workstations g q p while meeting required output ? Maintain technical precedence relationships ? Objectives
? ?
Office Note: 5 tasks or operations; 3 work stations
Maximize efficiency Minimize number of work stations
Assembly Line Balancing The General Procedure
? Determine cycle time by taking the demand (or production rate) per day and dividing it into the productive time available per day ? Calculate the theoretical minimum number of work stations by dividing total task time by cycle time ? Perform the line balance and assign specific assembly tasks to each work station
Cycle Time Example
Cd = cycle time, N= No. of work stations, Flow time = time taken to complete all stations production time available desired units of output
Cd = Cd =
(8 hours x 60 minutes / hour) (120 units)
Cd =
480 120
= 4 minutes
Flow Time vs Cycle Time
? Cycle time = max time spent at any station ? Flow time = time to complete all stations
1
4 minutes
Efficiency of Line and Balance Delay
Efficiency Minimum number of workstations i
?t
E=
i=1
i
i
?t
i=1
? Balance delay
? ?
i
2
4 minutes
3
4 minutes
where
nCa
ti j n Ca Cd
N=
Cd
total idle time of line calculated as (1 efficiency)
Flow time = 4 + 4 + 4 = 12 minutes Cycle time = max (4, 4, 4) = 4 minutes
= completion time for element i = number of work elements = actual number of workstations = actual cycle time = desired cycle time
Line Balancing Procedure
Draw and label a precedence diagram Calculate desired cycle time required for line Calculate theoretical minimum number of workstations Group elements into workstations, recognizing cycle time and workstations precedence constraints 5. Calculate efficiency of line 6. Determine if theoretical minimum number of workstations or an acceptable efficiency level has been reached. If not, go back to step 4. 1. 2. 3. 4. 4
A B C D
Line Balancing: Example
WORK ELEMENT Press out sheet of fruit Cut into strips Outline fun shapes Roll up and package 0.2 PRECEDENCE — A A B, C TIME (MIN) 0.1 0.2 0.4 0.3
B
0.1
A C
0.4
D
0.3
Line Balancing: Example (cont.)
WORK ELEMENT A B C D Press out sheet of fruit Cut into strips Outline fun shapes Roll up and package PRECEDENCE — A A B, C TIME (MIN) 0.1 0.2 0.4 0.3
Line Balancing: Example (cont.)
WORKSTATION 1 2 3 ELEMENT A B C D 0.2 REMAINING TIME 0.3 0.1 0.0 0.1 01 REMAINING ELEMENTS B, C C, D D none Cd = 0.4 N = 2.5
40 hours x 60 minutes / hour 2400 Cd = = = 0.4 minute 6,000 units 6000 0.1 0.1 + 0.2 + 0.3 + 0.4 1.0 N= = = 2.5 0.4 0.4 3 workstations
B A C
0.4
D
0.3
Line Balancing: Example (cont.)
Computerized Line Balancing
Use heuristics to assign tasks to workstations
Longest operation time Shortest operation time Most number of following tasks Least number of following tasks Ranked positional weight
Work station 1
Work station 2
Work station 3
Cd = 0.4 N = 2.5
A, B
0.3 minute
C
0.4 minute
D
0.3 minute
E=
1.0 0.1 + 0.2 + 0.3 + 0.4 = = 0.833 = 83.3% 1.2 3(0.4)
doc_316488511.pdf
Layout Strategy - Operations Management
McDonald’s - New Kitchen Layout
? Fifth major innovation - kitchen design
? ? ? ?
Layout Strategy
? ? ? ?
No food prepared ahead except patty Elimination of some steps, shortening of others New bun toasting machine (11 seconds vs 30 seconds) Repositioning condiment containers ( p g (one motion, not two) ) Sandwiches assembled in order Production levels controlled by computer Discard only meat when sandwiches do not sell fast enough Savings of $100,000,000 per year in food costs
McDonald’s - New Kitchen Layout
?No food prepared ahead except patty ?Elimination of some steps, shortening of others ?New bun toasting machine (11 seconds vs 30 seconds) ?Repositioning condiment containers (one motion, not two)
Innovation at McDonald’s
? Indoor seating (1950’s) ? Drive-through window (1970s) ? Adding breakfast to the menu (1980s) ? Adding play areas (1990s) (three out of the four are layout decisions)
What is Facility Layout
? Location or arrangement of everything within & around buildings
?
Functional Lay out
Objectives are to maximize
? ? ? ?
Customer satisfaction Utilization of space, equipment, & people Efficient flow of information, material, & people Employee morale & safety
? Savings of upto 30% of manufacturing (incl. inventory) costs possible by using proper layout
Functional Lay Out – Machines with Similar Functions Grouped Together
A Product Layout
In
Cellular Lay Out
Out
Each cell processes a family of products with similar sequence of operations
Six Layout Strategies
? Fixed-position layout
?
Six Layout Strategies - continued
? Retail/service layout
?
large bulky projects such as ships and buildings deals with low-volume high-variety production (“job low volume, high variety ( job shop”, intermittent production) positions workers, their equipment, and spaces/offices to provide for movement of information
? Process-oriented layout
?
allocates shelf space and responds to customer behavior addresses t d ff b t dd trade-offs between space and materiall d t i handling seeks the best personnel and machine use in repetitive or continuous production
? Warehouse layout
?
? Office layout
?
? Product-oriented layout
?
Layout Strategies
Project
(fixed-position)
FixedFixed-Position Layout
Repetitive /Continuous
(productoriented)
Job Shop
(Processoriented)
Office
Retail
Warehouse
(storage)
Examples
Ingal Ship Building Corp. Trump Plaza
Pittsburgh Airport
Shouldice Hospital Olive Garden
Allstate Insurance Microsoft
Kroger’s Supermarket Walgreens Bloomingdales
Federal-Mogul’s Warehouse The Gap’s distribution center
Sony’s TV Assembly Line Dodge Caravans Minivans Equalize the task time at each workstation
? Design is for stationary project ? Workers and equipment come to site ? Complicating factors
Limited space at site Changing material needs- at each stage of project ? Dynamic volumes at each stage
? ?
Problem
Move material to the limited storage areas around the site Manage varied Locate workers material flow for requiring each product frequent contact close to each other Expose customer to high-margin items Balance lowcost storage with low-cost material handling
ProcessProcess-Oriented Layout
? Design places departments with large flows of material or people together p g processes ? Department areas having similar p located in close proximity
?
Emergency Room Layout
E.R.Triage room
Patient A broken leg Patient B - erratic pacemaker
Hallway
e.g., All x-ray machines in same area
? Used with process-focused processes
E.R. beds Pharmacy Billing/exit
Steps in Developing a ProcessProcess-Oriented Layout
1 Construct a “from-to matrix” 2 Determine space requirements for each department p g 3 Develop an initial schematic diagram 4 Determine the cost of this layout 5 By trial-and-error (or more sophisticated means), try to improve the initial layout 6 Prepare a detailed plan that evaluates factors in addition to transportation cost
Cost of Process-Oriented Layout ProcessMinimize cost = ?? X ij C ij
i =1 j=1 n n
where n = total number of work centers or departments i, j = individual departments X ij = number of loads moved from department i to department j C ij = cost to move a load between department i and department j
Interdepartmental Flow of Parts
1 1 2 3 4 5 6 2 3 4 5 6
Interdepartmental Flow Graph Showing Number of Weekly Loads
100
1
50
100 30
0 50 20
0 10 0 50
20 0 100 0 0
4
50
2
30
3
100 10 50
5 6
Possible Layout 1
Room 1 Assembly Department (1) Receiving Department (4) Room 4 Room 2 Printing Department (2) Shipping Department (5) Room 5 60’ Room 2 Machine Shop Department (3) Testing Department (6) Room 6 40’
Interdepartmental Flow Graph Showing Number of Weekly Loads
30
1
50
2
100
3
100
4
50
5
6
Possible Layout 3
Room 1 Painting Department (2) Receiving Department (4) Room 4 Room 2 Assembly Department (1) Shipping Department (5) Room 5 60’ Room 2 Machine Shop Department (3) Testing Department (6) Room 6 40’
Computer Programs to Assist in Layout
? CRAFT ? SPACECRAFT ? CRAFT 3-D ? MULTIPLE ? CORELAP ? ALDEP ? COFAD ? FADES - expert system
OutOut-Patient Hospital Example
CRAFT
Legend: A = xray/MRI rooms B = laboratories C = admissions D = exam rooms E = operating rooms F = recovery rooms
Office Layout
5 B B E 6 B B E
1 1 A 2 A 3 D 4 C 5 F 6 E
2 A A D
3 A A D
4 A A D
5 B B D
6 B B D
1 1 D 2 D 3 D
2 D D D
3 D D D
4 D D E
? Design positions people, equipment, & offices for maximum information flow ? Arranged by process or product
?
Example: Payroll dept. is by p p y p y process
C D D D D F F F F D E E E E D
4 C C D E E F 5 A A A A A F 6 A A A F F F
Total cost: 14,390 Est. Cost Reduction 70. Iteration 3
? Relationship chart used ? Examples
? ?
Total cost: 20,100 Est. Cost Reduction .00 Iteration 0
Insurance company Software company
Office Layout Floor Plan
1 President 2 Costing
Relationship Chart
1
O A 3 Engineering O 4 President’s Secretary
I = Important U = Unimportant
Finance Manager
Accounting
Fin. Acct.
2
U I
3
A
Ordinary closeness: President (1) & Costing (2)
4
Brand X
Absolutely necessary: President (1) & Secretary (4)
Office Relationship Shart
1 President 2 Chief Technology Officer 3 Engineer’s Area 4 Secretary y 5 Office entrance 7 Equipment cabinet 8 Photocopy equipment 9 Storage room 9 Storage room O A O A U I I
Val. Closeness
Retail/Service Layout
Absolutely necessary Especially p y important Important Ordinary OK Unimportant Not desirable
A I I
I U O O A E U O X E E U U A O O U I O X U A E E I
I
A E I O U X
? Design maximizes product exposure to customers ? Decision variables
? ?
Store flow pattern Allocation of (shelf) space to products Video
? Types
Grid design ? Free-flow design
?
Retail Layouts Some Rules of Thumb
? Locate high-draw items around the periphery of the store ? Use prominent locations such as the first or last aisle for high-impulse and high margin items ? Remove crossover aisles that allow customers the opportunity to move between aisles ? Distribute what are known in the trade as “power items” (items that may dominate a shopping trip) to both sides of an aisle, and disperse them to increase the viewing of other items ? Use end aisle locations because they have a very high exposure rate
Retail /Service Layout Grid Design
Grocery Store
Bread
Milk
Meat
Produce Frozen Foods
Office
Carts
CheckCheckout
Store Layout - with Dairy, Bread, High Drawer Items in Corners
Retail/Service Layout FreeFree-Flow Design
Apparel Store Feature Trans. Counter Display Table
Retail Store Shelf Space Planogram
? Computerized tool for shelf-space management ? Generated from store’s scanner data on sales ? Often supplied by manufacturer ? Example: P&G
PERT PERT PERT PERT PERT
Warehouse Layout
5 facings
VO-5
VO-5
VO-5
SUAVE
SUAVE
? Design balances space (cube) utilization & handling cost ? Similar to process layout ? Items moved between dock & various storage areas ? Optimum layout depends on
Variety of items stored ? Number of items picked
?
VO-5 VO-5
2 ft. ft.
Warehouse Layout Floor Plan
Conveyor
Truck
?
Cross Docking
? Transferring goods
from incoming trucks at receiving docks ? to outgoing trucks at shipping docks
InIncoming
Outgoing
Zones
Order Picker
? Avoids placing goods into storage ? Requires suppliers provide effective addressing (bar codes) and packaging that provides for rapid transhipment
Random Stocking Systems Often:
? Maintain a list of “open” locations ? Maintain accurate records of existing inventory and its locations ? Sequence items on orders to minimize travel time required to pick orders ? Combine orders to reduce picking time ? Assign certain items or classes of items, such as high usage items, to particular warehouse areas so that distance traveled is minimized
An Assembly Line Layout
Repetitive Layout
Work
Assembly Line Balancing
(Design of Product Layout) Work Station
1
Station
3
4
Work Station
2
5
Belt Conveyor
? Analysis of production lines :for required volumes ? Nearly equally divides work between workstations g q p while meeting required output ? Maintain technical precedence relationships ? Objectives
? ?
Office Note: 5 tasks or operations; 3 work stations
Maximize efficiency Minimize number of work stations
Assembly Line Balancing The General Procedure
? Determine cycle time by taking the demand (or production rate) per day and dividing it into the productive time available per day ? Calculate the theoretical minimum number of work stations by dividing total task time by cycle time ? Perform the line balance and assign specific assembly tasks to each work station
Cycle Time Example
Cd = cycle time, N= No. of work stations, Flow time = time taken to complete all stations production time available desired units of output
Cd = Cd =
(8 hours x 60 minutes / hour) (120 units)
Cd =
480 120
= 4 minutes
Flow Time vs Cycle Time
? Cycle time = max time spent at any station ? Flow time = time to complete all stations
1
4 minutes
Efficiency of Line and Balance Delay
Efficiency Minimum number of workstations i
?t
E=
i=1
i
i
?t
i=1
? Balance delay
? ?
i
2
4 minutes
3
4 minutes
where
nCa
ti j n Ca Cd
N=
Cd
total idle time of line calculated as (1 efficiency)
Flow time = 4 + 4 + 4 = 12 minutes Cycle time = max (4, 4, 4) = 4 minutes
= completion time for element i = number of work elements = actual number of workstations = actual cycle time = desired cycle time
Line Balancing Procedure
Draw and label a precedence diagram Calculate desired cycle time required for line Calculate theoretical minimum number of workstations Group elements into workstations, recognizing cycle time and workstations precedence constraints 5. Calculate efficiency of line 6. Determine if theoretical minimum number of workstations or an acceptable efficiency level has been reached. If not, go back to step 4. 1. 2. 3. 4. 4
A B C D
Line Balancing: Example
WORK ELEMENT Press out sheet of fruit Cut into strips Outline fun shapes Roll up and package 0.2 PRECEDENCE — A A B, C TIME (MIN) 0.1 0.2 0.4 0.3
B
0.1
A C
0.4
D
0.3
Line Balancing: Example (cont.)
WORK ELEMENT A B C D Press out sheet of fruit Cut into strips Outline fun shapes Roll up and package PRECEDENCE — A A B, C TIME (MIN) 0.1 0.2 0.4 0.3
Line Balancing: Example (cont.)
WORKSTATION 1 2 3 ELEMENT A B C D 0.2 REMAINING TIME 0.3 0.1 0.0 0.1 01 REMAINING ELEMENTS B, C C, D D none Cd = 0.4 N = 2.5
40 hours x 60 minutes / hour 2400 Cd = = = 0.4 minute 6,000 units 6000 0.1 0.1 + 0.2 + 0.3 + 0.4 1.0 N= = = 2.5 0.4 0.4 3 workstations
B A C
0.4
D
0.3
Line Balancing: Example (cont.)
Computerized Line Balancing
Use heuristics to assign tasks to workstations
Longest operation time Shortest operation time Most number of following tasks Least number of following tasks Ranked positional weight
Work station 1
Work station 2
Work station 3
Cd = 0.4 N = 2.5
A, B
0.3 minute
C
0.4 minute
D
0.3 minute
E=
1.0 0.1 + 0.2 + 0.3 + 0.4 = = 0.833 = 83.3% 1.2 3(0.4)
doc_316488511.pdf