1. Facility Design Issues

2. Back to the course objectives... Forecasting Strategic Planning Aggregate Production Planning Disaggregation Production Scheduling Shop Floor Control Adminstrative Functions (Purchasing, Payroll, Finannce, Accounting) Marketing Product design Process Planning Manufacturing Support (Facilities Planning, Tool Management, Maintenance, Quality Control) Raw material Fabrication Assembly Distribution Center Retailer Customer Parts Finished Products Product Flow Prod. Plan. & Control Dec. Hierarchy Supporting Tech. & Admin. Functions

3. A typical (logical) Organization of the Production Activity Raw Material & Comp. Inventory Finished Item Inventory S1,2 S1,1S1,n S2,1S2,2S2,m Assembly Line 1: Product Family 1 Assembly Line 2: Product Family 2 Fabrication (or Backend Operations) Dept. 1Dept. 2Dept. k S1,i S2,i Dept. j

4. Problems to be addressed Spatial arrangement of the various departments /production units in a process-based layout Cell formation in cellular manufacturing (Assembly) line balancing

5. Design of Process-based layouts Arrange spatially the facility departments in a way that facilitates the flow of parts through the facility by minimizing the material handling / traveling effort; observes additional practical constraints arising from, e.g., processing/operational requirements safety/health considerations aesthetics building features etc.

6. Prevailing Methodology: Systematic Layout Planning (SLP) Departments  Activities 1. Material Flows 2. Activity Relationships 3. REL Chart 4. REL Diagram 5. Space Requirements 6. Space REL Diagram 7. Space Availability 8. Layout Alternatives

7. Designing Cellular Layouts The key idea: Establish “mini-factories” within the entire plant, dedicated to parts with similar processing requirements. These mini-factories are called cells, and the associated part groups are called part families. It’s a “divide & conquer” approach that tends to establish a more orderly operational environment than that resulting from a process-based layout, and at the same time, it avoids the excessive capital investment (through equipment duplication) required by the product-based layout. Some more specific benefits include –set-up time reduction –WIP reduction –improvement in labor and space utilization –improvement in employee morale –etc.

8. The underlying clustering problem Partition the entire set of parts to be produced on the plant-floor into a set of part families, with parts in each family characterized by similar processing requirements, and therefore, supported by the same cell. Part-Machine Indicator Matrix

9. Assembly Line Balancing Given: –a set of m tasks, each requiring a certain (nominal) processing time t_i, and –a set of precedence constraints regarding the execution of these m tasks, assign these tasks to a sequence of k workstations, in a way that –the total amount of work assigned to each workstation does not exceed a pre-defined cycle time c, (constraint I) –the precedence constraints are observed, (constraint II) –while the number of the employed workstations k is minimized. (objective) Remark: The problem is hard to solve optimally, and quite often it is addressed through heuristics.