1. IENG 471 Facilities Planning
IENG Lecture 15
Layout Planning –
Systematic Layout Planning & Intro to
Mathematical Layout Improvement
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IENG 471 Facilities Planning
(c) D.H. Jensen

2. Warehousing Terms - Review
SKU – Stock Keeping Unit
Product in (packaged) form for warehouse operations.
Value-Added
A modification to the product to obtain business
(a product enhancement from the customer’s perspective or an enhancement to the customer’s experience in getting the item).
Cross-Docking
Transforming incoming product to outgoing product without moving the product to production or storage.
Slotting
Selecting the location of SKUs in the storage zones. Goal is to optimize (reduce) pick times across all SKUs within a zone.
Forward Pick Area
An area housing fast-moving/frequently-picked items between the shipping and storage areas for quick order fulfillment.
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IENG 471 Facilities Planning

3. Layout Alternatives - Strategies
Fixed Position Layout
(Difficult-to-move Products)
Process Layout
(Job Shop)
Product Layout
(Mass Production Line)
Group Technology Layout
(Product Family)
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IENG 471 Facilities Planning

4. Layout Alternatives: Fixed Pos.
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IENG 471 Facilities Planning

5. Layout Alternatives: Process
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6. Layout Alternatives: Product
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7. Layout Alternatives: GT / Family
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IENG 471 Facilities Planning

8. How to get from data to design?
Product, Process & Schedule Data:
BOM
Routing/Assembly Chrt
Operations Process Chart
Precedence Diagram
Scrap/Reject Rates
Equipment Fractions
Material Handling
Unit Loads
Storage Systems
Efficiencies
Transportation Systems
Flow, Activity &
Space Data:
Group Technology
From – To Chart
Relationship Chart
Dept Footprint & Aisle Space
Personnel Space
Parking Lot
Restroom/Locker room
Food Prep/Cafeteria
ADA Compliance
Order Data Profile
Multiple Analysis Profiles
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IENG 471 Facilities Planning

9. Muther: Systematic Layout Plan
SLP
Benefit is methodical consideration of issues
Can work the process manually or with computer aides
“Roadmap” for the process is good for communication
Adds the following stages:
Analysis
Search
Evaluation
Engineering Design Process!
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IENG 471 Facilities Planning

10. IENG 471 Facilities Planning
In-Class Example
Recognize Need
Generate scenario
Collect Data
What info
Analyze Data
Combine Flow & Relationship  Affinity Diagram
Generate Design
Expand Affinity Diagram to encompass work space
Multiple Designs!
Evaluate
Criteria Needed!
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IENG 471 Facilities Planning

11. Relationship Chart - Qualitative
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12. Converting Closeness to Affinity
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13. IENG 471 Facilities Planning
From – To Chart Example
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IENG 471 Facilities Planning

14. IENG 471 Facilities Planning
From – To Chart to Flow
Review: flow volume in chart
Above diagonal is forward flow
Below diagonal is back-track flow
Combine both flows to represent volume of interactions, then Pareto!
Qualitative Flow
Quantitative Flow
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IENG 471 Facilities Planning

15. Converting Quantitative Flow to Affinity
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16. Converting Both to Final Affinity
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17. Review: Conversion Steps
Convert Flows to Affinities
Qualitative converts directly to A E I O U X
Quantitative converts to A E I O U X via Pareto analysis of flow volume
Combine Flow Affinities Numerically
A = 4, E = 3, I = 2, O = 1, U = 0, X = negative value
Quantitative flow may be multiplied by a weighting factor
Sum Quantitative & Qualitative
Convert to Final Affinities
Pareto analysis of numeric affinities to get A E I O U X
Add: Check Final Affinities for Political Correctness
Communication feedback to involved parties
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IENG 471 Facilities Planning

18. Converting Flow to Affinity
Strength of relationship is shown graphically
Number of lines similar to rubber bands holding depts together
Spring symbol to push X relations apart
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IENG 471 Facilities Planning

19. Converting Flow to Affinity
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20. Converting Flow to Affinity
Lay the Affinity Diagram over a site plan to get better idea of layout
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IENG 471 Facilities Planning

21. Improvement: Size of Departments
Some experts suggest modification:
Use circles instead of flow symbols
Scale circles to equate with the estimated size of the departments
Use rectangular, sized blocks instead of circles – improves input to computer layout methods
Computer packages are still being developed …
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IENG 471 Facilities Planning

22. Layout Models – Mathematical Objective Functions
Mathematical models can be constructed to measure a design, and help to quantify when it has been improved
Like many mathematical models of physical systems, part of the “art” is knowing what assumptions are made in a model, and when these assumptions are “reasonably met”
The “best” models are not always the most complex – in fact many “comprehensive” mathematical models become intractable or take too long for computation when scaled up to a “realistically–sized” problem
Frequently, meeting the data collection (and verification) requirements for many mathematical problems is very difficult
However, as the cost of automated data collection and storage drops, and has computational power increases (hardware speeds and parallel programming techniques improve), both mathematical models and simulations become more attractive – more tools for the toolbox!
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IENG 471 Facilities Planning

23. Layout Models – Mathematical Objective Functions
Assume we have these variables defined for n departments:
i is an index to the “FROM” department in a pair of departments
j is an index to the “TO” department in a related pair
Thus i and j could be the row/column indices for a From/To Chart
fij is the unit load FLOW from the i th to the j th department
Thus fij is the cell entry in the From/To Chart (matrix)
cij is the COST to transport a unit load from the i th to the j th dept
dij is the travel DISTANCE from the i th to the j th department
aij is the ADJACENCY of the i th and j th department pair, which is defined to be:
1 if the i th and j th departments share a common edge (border) – or
0 if the departments have no common edge or only touch at a point
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IENG 471 Facilities Planning

24. Layout Models – Mathematical Objective Functions
Minimize the transportation cost:
Maximize the flow-weighted adjacency of departments:
Evaluate flow weighted layout efficiency (relative measure):
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IENG 471 Facilities Planning

25. Example – Mathematical Objective Function
Assume the From/To matrix (below)
… and the department layout(s) (below):
then the Flow-Weighted Adjacency score(s) would be:
200(1)+250(1)+300(1)+500(1)–20(1)+350(0)+10(1)+175(1)+100(0) = 1415
200(1)+250(1)+300(1)+500(1)–20(0)+350(0)+10(1)+175(1)+100(0) = 1435
200(1)+250(0)+300(1)+500(1)–20(0)+350(1)+10(0)+175(1)+100(1) = 1625
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IENG 471 Facilities Planning

26. Criticisms and Resources
Frequently, improvements in the simpler mathematical objective functions result in long, “snake-y” department shapes
Not always physically possible
Adjusting the objective function to penalize snake-y results in more complex objective functions
Data representations become more complex, too – and can increase computation time disproportionately
The simple, transportation cost function assumes we move from/to the center “point” of the departments
Isn’t really accurate for real departments (especially large sized)
Becomes even less true when the departments get more snake-y
Text Chapter 10 presents more mathematical models–try some!
MIL Lab computers have some software available
The software tends to be research prototypes, but can be fun to try!
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IENG 471 Facilities Planning

27. IENG 471 Facilities Planning
Questions & Issues
Class time is for project (after Exam II)
Review & HW solutions TODAY.
Exam II scheduled for 07 NOV.
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IENG 471 Facilities Planning