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DAVIS AQUILANO CHASE PowerPoint Presentation by Charlie Cook. Facility Decisions: Layouts. F O U R T H E D I T I O N. chapter 8. © The McGraw-Hill Companies, Inc., 2003. Chapter Objectives.
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DAVIS AQUILANO CHASE PowerPointPresentation by Charlie Cook Facility Decisions:Layouts F O U R T H E D I T I O N chapter 8 © The McGraw-Hill Companies, Inc., 2003
Chapter Objectives • Introduce the different types of facility layouts that can be used in designing manufacturing and service operations. • Present a methodology for designing a process-oriented layout. • Introduce the concept of takt time and its relationship to the output capacity of a product-oriented layout. • Identify the various steps and elements that are involved in balancing an assembly line. • Discuss the current trends in facility layouts given today’s shorter product life cycles and the customer’s increasing desire for customized products. Fundamentals of Operations Management 4e
Managerial Issues • Recognizing that many factors must be considered in choosing how to layout a facility. • Understanding the significant impact that choosing a particular type of layout has on the firm’s ability to compete in the market and its long-term success. • Developing estimates of the investment costs of time and money associated with installing a particular layout. • Attaining the goal of a smooth flow of material through the process through the choice of a layout that is both efficient and effective. Fundamentals of Operations Management 4e
Types of Manufacturing Layouts Fundamentals of Operations Management 4e
Characteristics of a Good Layout Exhibit 8.1 Fundamentals of Operations Management 4e
Interdepartmental Flow Exhibit 8.2 Fundamentals of Operations Management 4e
Building Dimensions and Departments Exhibit 8.3 Fundamentals of Operations Management 4e
Interdepartmental Flow Graph withNumber of Annual Movements Exhibit 8.4 Fundamentals of Operations Management 4e
Cost Matrix—First Solution Exhibit 8.5 Fundamentals of Operations Management 4e
Revised Interdepartmental Flowchart* *Only interdepartmental flow with effect on cost is depicted. Exhibit 8.6 Fundamentals of Operations Management 4e
Cost Matrix—Second Solution Exhibit 8.7 Fundamentals of Operations Management 4e
Revised Building Layout Exhibit 8.8 Fundamentals of Operations Management 4e
Product Layout • Assembly Lines • A progressive paced assembly linked by some sort of material handling device. • Assembly Line Type Differences • Material handling devices • Line configuration • Pacing (machine or human) • Product mix • Workstation characteristic • Length of line Fundamentals of Operations Management 4e
Product Layout: Key Terms • Product Interval Time • The time between products being completed (processed through) at a single station (process step). Also cycle time or takt time. • Product Duration (Throughput) Time. • The overall time required to entirely complete an individual product. • Assembly Line Balancing • Assignment of tasks to workstations within a given cycle time and with minimum idle worker time. Fundamentals of Operations Management 4e
Assembly Line Balancing Steps • Specify the sequential relationships among tasks using a precedence diagram. • Determine the required takt (T) time. • Determine the theoretical minimum number of workstations (Nt) required to satisfy the takt time constraint. • Select a primary rule by which tasks are to be assigned to workstations and a secondary rule to break ties. Fundamentals of Operations Management 4e
Assembly Line Balancing Steps (cont’d) • Assign tasks, one at a time, to the first workstation until the sum of the task times is equal to the takt time. Continue assigning tasks to other workstations until all tasks are assigned. • Evaluate the efficiency of the resulting assembly line. • If efficiency is unsatisfactory, rebalance the line using a different decision rule in step 4. Fundamentals of Operations Management 4e
Takt Time and Throughput Time on an Assembly Line Matching task time to takt time: • Split the task • Duplicate the station • Share the task • Use a more skilled worker • Work overtime • Redesign the product Exhibit 8.9 Fundamentals of Operations Management 4e
Production time per day = Takt time (T) Output per day (in units) Sum of task times (S) Number of workstations = Takt time (T) Sum of task times (S) = Efficiency ´ workstations (Na) Actual number of Takt time (T) Assembly Line Balancing Formulas Fundamentals of Operations Management 4e
Assembly Steps and Times for Model J Wagon Exhibit 8.10 Fundamentals of Operations Management 4e
Precedence Graph for Model J Wagon Exhibit 8.11 Fundamentals of Operations Management 4e
A Balance Made According to Largest Number of Following Tasks Rule Exhibit 8.12a Fundamentals of Operations Management 4e
Precedence Graph for Model J Wagon Exhibit 8.12B Fundamentals of Operations Management 4e
Efficiency Calculation Exhibit 8.12C Fundamentals of Operations Management 4e
Flexible Line Layouts Source: Robert W. Hall, Attaining Manufacturing Excellence (Homewood, IL: Dow Jones-Irwin, 1987), p. 125. Exhibit 8.13 Fundamentals of Operations Management 4e
Group Technology (Cellular) Layout • Benefits • Better human relations in small work teams. • Improved operator expertise from the limited number of parts and quick production cycle. • Less work-in-process inventory and material handling due to reduced number of production stages. • Faster production setup from faster tooling changes. Fundamentals of Operations Management 4e
Group Technology (GT) Layout • Developing a GT Layout • Grouping parts into families that follow a common sequence of steps. • Identifying dominant flow patterns of parts-families for location of processes. • Physically grouping machines and processes into cells. Fundamentals of Operations Management 4e
Facilities Layout for Services • Goals of Service Facility Layouts • Minimize travel time for workers and customers • Maximize revenues from customers • Types of Service Layouts • Process layout—emergency rooms • Product layout—cafeteria line • Fixed-position layout—automobile repair shop Fundamentals of Operations Management 4e
Facilities Layout for Services • Servicescape • The aspects of the physical surroundings in a service operation that can affect a customer’s perception of the service received. • Ambient conditions • Noise, lighting, and temperature • Spatial layout and functionality • Minimizing employee travel time and maximizing revenue opportunities from customers • Signs, symbols, and artifacts • Objects that create positive images of the firm Fundamentals of Operations Management 4e