Part 3

How do you coordinate the facility? What is Facility Layout Design? Facility layout means planning: – for the location of all machines, utilities, employee workstations, customer service areas, material storage areas, aisles, restrooms, lunchrooms, internal walls, offices, and computer rooms – for the flow patterns of materials and people around, into, and within buildings. (Houseman, Slide 2)

Product Layout Advantages Limitations Smooth, simple, direct flow Small work-in-process inv. Short production time/unit Reduced material handling Less skill Easy production control Line stoppage Product design changes Slowest station paces the line General supervision High equipment investment

Process Layout Advantages Limitations Increased machine utilization General purpose equipment Highly flexible Diversity of tasks Increased material handling Complicated production control Increased work-in-process Longer production lines Higher skills required

32 Layout Types (a) Layout of a job shop Figure 7.3 Foundry Milling machines LathesGrinding PaintingDrills Office Welding Forging (b) Layout of a production line Station 1Station 2Station 3Station 4

33 Hybrid Layout  Cellular layouts  Group machines into machining cells  Flexible manufacturing systems  Automated machining & material handling systems  Mixed-model assembly lines  Produce variety of models on one line

34 Hybrid Layout: Group Technology Machine 1 Machine 2 Machine 3 Machine 4 Machine 5 Materials in Finished goods out One Worker, Multiple Machines

35 Group Technology Figure 7.5 Drilling DD DD Grinding GG GG GG Milling MM MM MM Assembly AA AA Lathing Receiving and shipping L LL LL LL L (a) Jumbled flows in a job shop without GT cells

36 Group Technology (b) Line flows in a job shop with three GT cells Cell 3 LM G G Cell 1 Cell 2 Assembly area A A L M D L L M Shipping D Receiving G Figure 7.5

37 Cellular Layout 1.Identify families of parts with similar flow paths 2.Group machines into cells based on part families 3.Arrange cells so material movement is minimized 4.Locate large shared machines at point of use In Out Worker 1 Worker 2 Worker 3 S L HM VM G L Final inspection Finished part

38 Advantages/Disadvantages of Cellular Layout Advantages  Reduced material handling and transit time  Reduced setup time  Reduced work-in- process inventory  Better use of human resources  Easier to control  Easier to automate Disadvantages  Inadequate part families  Poorly balanced cells  Expanded training and scheduling of workers  Increased capital investment

Group Layout Advantages Limitations By grouping, higher machine utilizations Smoother flow lines and shorter travel distances Team spirit and job enlargement Greater labor skills for team Balancing individual cells Unbalanced flow may result in work-in-process

Fixed product layout Advantages Limitations Reduced material moves Highly flexible Job enrichment Promotes pride & quality Responsibility Personel-equipment moves Equipment duplicates Greater skill Close control& coordination Increased space & greater work-in-process

Copyright 2006 John Wiley & Sons, Inc Designing Service Layouts Must be both attractive and functional Types – Free flow layouts encourage browsing, increase impulse purchasing, are flexible and visually appealing – Grid layouts encourage customer familiarity, are low cost, easy to clean and secure, and good for repeat customers – Loop and Spine layouts both increase customer sightlines and exposure to products, while encouraging customer to circulate through the entire store

Copyright 2006 John Wiley & Sons, Inc Types of Store Layouts

Designing Product Layouts Product layouts are different than process layouts Product layouts provide for sequential product movement that enhances efficiency Designing product layouts requires consideration of – Sequence of tasks to be performed by each workstation – Logical order – Speed considerations – line balancing

Copyright 2006 John Wiley & Sons, Inc Designing Product Layouts Objective – Balance the assembly line Line balancing – tries to equalize the amount of work at each workstation Precedence requirements – physical restrictions on the order in which operations are performed Cycle time – maximum amount of time a product is allowed to spend at each workstation

Designing Product Layouts - continued 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

Step 1: Identify Tasks & Immediate Predecessors

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):

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

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

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%

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 Number of products produced – Single – Mixed-model lines