Facility Layout

1. Facility Layout

2. What Is Layout Planning • Layout planning is determining the best physical arrangement of resources within a facility • Two broad categories of operations: • Intermittent processing systems • Continuous processing systems

3. Types of Layouts • Process layouts: • Group similar resources together • Product layouts: • Designed to produce a specific product efficiently • Hybrid layouts: • Combine aspects of both process and product layouts • Fixed-Position layouts: • Product is too large to move; e.g. a building

4. Process Layouts • General purpose & flexible resources • Lower capital intensity & automation • Higher labor intensity • Resources have greater flexibility • Processing rates are slower • Material handling costs are higher • Scheduling resources & work flow is more complex • Space requirements are higher

5. Product Layouts • Specialized equipment • High capital intensity & wide use of automation • Processing rates are faster • Material handling costs are lower • Less space required for inventories • Less volume or design flexibility

6. Hybrid Layouts • Combine elements of both product & process layouts • Maintain some of the efficiencies of product layouts • Maintain some of the flexibility of process layouts • Examples: • Group technology & manufacturing cells • Grocery stores

7. Comparison of Product vs. Product Layouts Process Layouts Product Layouts Products: large #, different small # efficiently Resources: general purpose specialized Facilities: more labor intensive more capital intensive Flexibility: greater relative to market lower relative to market Processing slower faster Rates: Handling costs: high low Space requirements: higher lower

8. Designing Process Layouts • Step 1: Gather information: • Space needed, space available, importance of proximity between various units • Step 2: Develop alternative block plans: • Using trial-and-error or decision support tools • Step 3: Develop a detailed layout • Consider exact sizes and shapes of departments and work centers including aisles and stairways • Tools like drawings, 3-D models, and CAD software are available to facilitate this process

9. Process Layout Steps • Step 1: Gather information like space needed, from-to matrix, and REL Chart for Recovery First Sports Medicine Clinic (total space 3750 sq. ft.)

10. Step 1: Gather Information(continued)

11. Step 2: Develop a Block Layout • Use trial and error with from-to and REL Charts as a guide • Use computer software like ALDEP or CRAFT

12. Warehouse Layouts • Warehouse Layout Considerations: • Primary decision is where to locate each department relative to the dock • Departments can be organized to minimize “ld” totals • Departments of unequal size require modification of the typical ld calculations to include a calculation of the “ratio of trips to area needed” • The usage of “Crossdocking” (see Ch.4) modifies the traditional warehouse layouts; more docks, less storage space, and less order picking

13. Office Layouts • Office Layout Considerations: • Almost half of US workforce works in an office environment • Human interaction and communication are the primary factors in designing office layouts • Layouts need to account for physical environment and psychological needs of the organization • One key layout trade-off is between proximity and privacy • Open concept offices promote understanding & trust • Flexible layouts incorporating “office landscaping” help to solve the privacy issue in open office environments

14. Designing Product Layouts • Step 1: Identify tasks & immediate predecessors • Step 2: Determine the desired output rate • Step 3: Calculate the cycle time • Step 4: Compute the theoretical minimum number of workstations • Step 5: Assign tasks to workstations (balance the line) • Step 6: Compute efficiency, idle time & balance delay

15. Step 1: Identify Tasks & Immediate Predecessors

16. Layout Calculations • Step 2:Determine output rate • Vicki needs to produce 60 pizzas per hour • Step 3:Determine cycle time • The amount of time each workstation is allowed to complete its tasks • Limited by the bottleneck task (the longest task in a process):

17. Layout Calculations (continued) • Step 4:Compute the theoretical minimum number of stations • TM = number of stations needed to achieve 100% efficiency (every second is used) • Always round up (no partial workstations) • Serves as a lower bound for our analysis

18. Layout Calculations (continued) • Step 5:Assign tasks to workstations • Start at the first station & choose the longest eligible task following precedence relationships • Continue adding the longest eligible task that fits without going over the desired cycle time • When no additional tasks can be added within the desired cycle time, begin assigning tasks to the next workstation until finished

19. Last Layout Calculation • Step 6:Compute efficiency and balance delay • Efficiency (%) is the ratio of total productive time divided by total time • Balance delay (%) is the amount by which the line falls short of 100%

20. Other Product Layout Considerations • Shape of the line (S, U, O, L): • Share resources, enhance communication & visibility, impact location of loading & unloading • Paced versus un-paced lines • Paced lines use an automatically enforced cycle time • Single or mixed-model lines

21. Designing Hybrid Layouts • One of the most popular hybrid layouts uses Group Technology (GT) and a cellular layout • GT has the advantage of bringing theefficiencies of a product layout to a process layout environment

22. Process Flows before the Use of GT Cells

23. Process Flows after the Use of GT Cells