IENG 471 - Lecture 15

1. IENG 471 - Lecture 15 Layout Planning – Systematic Layout Planning & Intro to Mathematical Layout Improvement IENG 471 Facilities Planning

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 enhancementfrom 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. 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) IENG 471 Facilities Planning

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

5. Layout Alternatives: Process IENG 471 Facilities Planning

6. Layout Alternatives: Product IENG 471 Facilities Planning

7. Layout Alternatives: GT / Family IENG 471 Facilities Planning

8. 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 How to get from data to design? 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! IENG 471 Facilities Planning

10. Relationship Chart - Qualitative IENG 471 Facilities Planning

11. Converting Closeness to Affinity IENG 471 Facilities Planning

12. From – To Chart Example IENG 471 Facilities Planning

13. 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 IENG 471 Facilities Planning

14. Converting Quantitative Flow to Affinity IENG 471 Facilities Planning

15. Converting Both to Final Affinity IENG 471 Facilities Planning

16. 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 IENG 471 Facilities Planning

17. 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 IENG 471 Facilities Planning

18. Converting Flow to Affinity IENG 471 Facilities Planning

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

20. 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 … IENG 471 Facilities Planning

21. 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! IENG 471 Facilities Planning

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

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

24. 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 IENG 471 Facilities Planning

25. 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! IENG 471 Facilities Planning

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