1. *
07/16/96
Production Flow Analysis: A Foundation for Design of a “Lean” Facility Layout *

2. Symptoms of Inefficient Material Flows in a Facility
Large travel distances in the material flow diagram
Perceived shortage of floor-space for facility expansion
High WIP inventory levels
Large inter-machine transfer batch sizes
High levels of finished product inventories
Bottleneck resources with large queues
Large cycle times for order fulfillment
Significant queuing and material handling delays
Significant forklift truck activity
Poor order tracking capability
Highly unpatterned material flow network
Absence of a network of material handling aisles
Inefficient communications between workcenters
Low machine and labor utilization
Frequent machine setups
Absence of pull scheduling based on resource constraints
Inflexibility to handle demand and/or part mix changes

3. Causes of Poor Material Flows in a Facility
Building architecture
Locations of manufacturing departments
Locations of support services and utilities
Design of the network of material handling aisles
Locations of input/output points of departments
Shortage of space for facility expansion
Process plans for making parts and products
Variety of routings in the part mix
Current manufacturing technology
Current material handling equipment in use
Current material handling scheduling policies
Choice of subcontracted operations and/or parts

4. Benefits of Using PFA for Facility Layout
Verification and updating of operational and planning documents
Verification and updating of current equipment inventory
Review and improvement of business and manufacturing processes
Redesign of product designs
Redesign of process plans
Strategic reallocation of equipment between departments
Strategic duplication of equipment between departments
Strategic consolidation of departments
Strategic investment in flexible multi-function equipment
Planning for flexibility - machine, process, routing, volume, etc.
Implementation of capacity-constrained scheduling techniques
Implementation of efficient machine loading rules
Implementation of efficient job sequencing rules
Implementation of setup reduction practices
Revision of the product routings to eliminate redundant variety
Revision of the product routings to eliminate "outlier" routings

5. Reasons for the Project at Company X*
07/16/96
Reasons for the Project at Company X
Machines not located in close proximity
Machines not arranged according to the process flow
Backtracking in the process flow
A new layout would save floorspace
Lack of streamlined material and operator flows
The area and layout of several machine footprints are not optimized
WIP quantities at different machines differ significantly
Material is moved in large batches between machines
Significant delays in order throughput
Quality problems due to absence of feedback* between machines
* due to large distances of separation *

6. Reasons for the Project at Company X (cont’d)*
07/16/96
Reasons for the Project at Company X (cont’d)
No production planning, finite capacity scheduling system or shopfloor control systems to track and progress orders
Lack of prompt communications between the shopfloor and the production planner
Production lot sizes are not based on any systematically planned master production schedule
Difficulty in synchronizing production with the supply schedule for forgings *

7. “Design For Flow” Principles for Effective Layout Design
Maximize:
Directed flow
One piece flow
Ergonomics of material handling in every workcell
Visual scheduling and material flow control
Flexibility to accommodate variations in product mix and /or volume
Minimize:
Backtracking
Transfer batches
Travel distance in every workcell
Travel distances between consecutive workcells
WIP storage space between consecutive workcells*
* design of a standard storage cart (“Kanbin”)

8. Design of a Standard Storage Cart (“Kanbin”)
Original Design:
Proposed Design:

9. Routing for 6-cylinder Products

10. Routing for 4-cylinder Products

11. Comparison of Routings for 6-cylinder and 4-cylinder Products

12. Initial Layout of Company X Shopfloor

13. Flow Diagram for 6-cylinder Products
START
FINISH

14. Flow Diagram for 4-cylinder Products
START
FINISH

15. Preliminary Layouts Presented to Company X
Dock
Company X feedback on Layout #1*:
Allows direct line of sight between the Oven and the Wheelabrator
Does not require relocation of the Borringer
Keeps the Oven close to the dock — In the summer, heat can escape easily through the dock
* This layout was chosen by the company

16. Preliminary Layouts Presented to Company X
Dock
Company X feedback on Layout #2:
Oven cannot be moved into the position shown because the Borringer cannot be relocated
Prevents direct line of sight between the Oven and the Wheelabrator

17. Preliminary Layouts Presented to Company X
Dock
Company X feedback on Layout #3:
Oven cannot be moved into this position

18. Flow Diagram showing “Lean” Flow in an Initial Layout that was Proposed
Flow of both 6-cylinder and 4-cylinder products
Flow of 6-cylinder products only
Flow of 4-cylinder products only

19. Constraints on Layout Design
Borringer cannot be relocated.
Final Inspection Area cannot be located near the Dock because winter cold would affect parts and gauges.
M/Cs 757 and 1025 need 17' clearance on one side where their chip conveyors (17' in length) may need to be pulled out for machine maintenance.
M/C 567 (Mori Seiki) needs 13' clearance on one side where its chip conveyor (13' in length) may need to be pulled out for machine maintenance.
All M/Cs need to be accessed from at least one aisle for machine maintenance.
An inspection area (10' by 20') must be located centrally in the flowline.
The aisles could be used to accommodate large machines projecting out of a bay.
The 5th bay should be kept clear to implement new product lines. (See “Initial Layout of Company X Shopfloor” shown earlier)

20. Constraints on Layout Design (Cont’d)
Final Inspection Area constraints: M/Cs 776 and 736 (Grinders) and M/C 590 (Snag Grinder) create too much dust that could “corrupt” the Maggie. Therefore Maggie cannot be located adjacent to the Grinders.
Wet
Creates
Dust
Needs to be Dust Free
Maggie
Balancer
Needs to be Protected from Cold and Dust
* M/Cs in the Finish Grinding area were removed by Lycoming during the project period.
M/Cs #510 and #738 (Okuma & Howa) were taken out of the machining line.
M/C #109 (Bridgeport) was replaced by M/C #778.
M/Cs #795 ( Cincinnati Drill Press) and #759 (G&L Drill Press) were to be replaced by a new machine.

21. Final Layout based on “Lean” Flow
Incoming Cart
Dock
Operator’s Standing Point

22. Detailed Layout of Workcells
(M/Cs #380, #568 and #569) N
Note: All measurements are in feet.

23. Detailed Layout of Workcells
(M/C #768 and GFMs) N
Spacing Bench can be easily shared by two GFM operators
*The constraint of 17' clearance is satisfied for both GFMs in this layout.
Note: All measurements are in feet.

24. Detailed Layout of Workcells
(M/Cs #777 and #735) N
Leave 5' between the two M/Cs to minimize the operator’s travel distance
Note: All measurements are in feet.

25. Detailed Layout of Workcells
(M/Cs #567 and #724) N
AISLE
Note: All measurements are in feet.

26. Detailed Layout of Workcells
(M/Cs #763 and #843) N
AISLE
AISLE
Note: All measurements are in feet.

27. Detailed Layout of Workcells
(From M/C #756) N
Locate the vending machines in this way in order not to block the line of sight between consecutive workcells
Incoming “Kanbin” Cart
Operator’s Standing Point
Note: All measurements are in feet.

28. Detailed Layout of Workcells
(Operation #180 to Operation #235) N

29. Detailed Layout of Workcells
(Final Inspection Area) N
Note: All measurements are in feet.

30. Key Benefits of the “Lean” Layout
Pure flowline layout
Smooth workflow within every workcell
Space was “freed” to accommodate a new product line
Standardization of containers for WIP storage and transfer (“Kanbin”)
Decrease in transfer batch sizes
Reduction in floorspace due to proximity of cells
Optimization of several machine footprints
Improved communications between consecutive operations
Layout designed for and with full cooperation of Company X operators, supervisors and managers

31. Conclusion
“…..Thank you for the excellent work that you and your students did on the project. While it was a learning experience for us, I’m sure your students gained much more by seeing the classroom applied to the shop floor. It is rare to find an academician that is as comfortable on the shop floor as you are. This attribute helps not only the client using the service, but also the student, as it shows the student how it should be done in the “real world”.
I believe the partnership between a public university and private industry is extremely important as it enables the businesses in the State of Ohio to enjoy the fruits of a great institution of higher learning. The way to make manufacturing in Ohio competitive into the future is to do just what we did, apply academic principles to the practical world on the shop floor. We are on our way to becoming more profitable and competitive thanks to the work your team did at Company X…...”
Chief Financial Officer (Company X)

32. Schedule of Project Activities