Chapter 8 Facility decisions: Layouts, after studying this chapter you will be able to: 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,...
DAVIS F O U R T H E D I T I O N AQUILANO CHASE chapter Facility Decisions: Layouts © The McGraw-Hill Companies, Inc., 2003 PowerPoint Presentation by Charlie Cook Chapter Objectives 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 processoriented 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 © The McGrawHill increasing desire for customizedCompanies, Inc., 2003 products Fundamentals of Operations Management 4e 8–2 Managerial Issues 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 © The McGrawHill Fundamentals of Operations Companies, Inc., 2003 Management 4e 8–3 Types of Manufacturing Layouts Types of Manufacturing Layouts Layout Type Process Similar operations are performed in a common or functional area, regardless of the product in which the parts are used Product (Flow-shop layout) Equipment/operations are located according to the progressive steps required to make the product Group Technology (GT) or Cellular Groups of dissimilar machines are brought together in a work cell to perform tasks on a family of products that share common interests Fixed-Position The product, because of its size and/or weight, remains in one location and processes are brought to it © The McGrawHill Fundamentals of Operations Management 4e Companies, Inc., 2003 8–4 Characteristics of a Good Layout Characteristics of a Good Layout Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.1 8–5 Interdepartmental Flow Interdepartmental Flow Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.2 8–6 Building Dimensions and Departments Building Dimensions and Departments Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.3 8–7 Interdepartmental Flow Graph with Interdepartmental Flow Graph with Number of Annual Movements Number of Annual Movements Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.4 8–8 Cost Matrix Cost Matrix—First Solution —First Solution Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.5 8–9 Revised Interdepartmental Flowchart* Revised Interdepartmental Flowchart* *Only interdepartmental flow with effect on cost is depicted Fundamentals of Operations Management4e âTheMcGrawưHill Companies,Inc.,2003 Exhibit 8.6 810 ProductLayout:KeyTerms ProductLayout:KeyTerms ã 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 © The McGrawHill time Fundamentals of Operations Companies, Inc., 2003 Management 4e 8–14 Assembly Line Balancing Steps 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 © The McGrawHill Companies, Inc., 2003 8–15 Assembly Line Balancing Steps (cont’d) 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 Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 8–16 Takt Time and Throughput Time Takt Time and Throughput Time on an Assembly Line 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 Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.9 8–17 Assembly Line Balancing Formulas Assembly Line Balancing Formulas Production time per day Takt time (T) Output per day (in units) Sum of task times (S) Number of workstations Takt time (T) Efficiency Sum of task times (S) Actual number of workstations (Na) Takt time (T) © The McGrawHill Fundamentals of Operations Companies, Inc., 2003 Management 4e 8–18 Assembly Steps and Times for Model J Wagon Assembly Steps and Times for Model J Wagon Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.10 8–19 Precedence Graph for Model J Wagon Precedence Graph for Model J Wagon Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.11 8–20 A Balance Made According to A Balance Made According to Largest Number of Following Tasks Rule Largest Number of Following Tasks Rule Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.12a 8–21 Precedence Graph for Model J Wagon Precedence Graph for Model J Wagon Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.12B 8–22 Efficiency Calculation Efficiency Calculation Efficiency Efficiency S NT 195 50.4 Fundamentals of Operations Management 4e 0.77, or 77% © The McGrawHill Companies, Inc., 2003 Exhibit 8.12C 8–23 Flexible Flexible Line Line Layouts Layouts Fundamentals of Operations Management 4e Source: Robert W Hall, Attaining Manufacturing Excellence (Homewood, IL: Dow Jones-Irwin, 1987), p 125 © The McGrawHill Companies, Inc., 2003 Exhibit 8.13 8–24 Group Technology (Cellular) Layout 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 © The McGrawHill Companies, Inc., 2003 8–25 Group Technology (GT) Layout Group Technology (GT) Layout • Developing a GT Layout –Grouping parts into families that follow a common sequence of steps –Identifying dominant flow patterns of partsfamilies for location of processes –Physically grouping machines and processes into cells Fundamentals of Operations Management 4e © The McGrawHill Companies, Inc., 2003 8–26 Facilities Layout for Services 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 © The McGrawHill Companies, Inc., 2003 8–27 Facilities Layout for Services 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 ã Objects that create positive âTheMcGrawưHill images of the firm Fundamentals of Operations Companies, Inc., 2003 Management 4e 8–28 ... © The McGrawHill Fundamentals? ?of? ?Operations? ? Management? ?4e Companies, Inc., 2003 8–4 Characteristics? ?of? ?a Good Layout Characteristics? ?of? ?a Good Layout Fundamentals? ?of? ?Operations? ? Management? ?4e © The McGrawHill ... Number? ?of? ?Annual Movements Fundamentals? ?of? ?Operations? ? Management? ?4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.4 8–8 Cost Matrix Cost Matrix—First Solution —First Solution Fundamentals? ?of? ?Operations? ? Management? ?4e ... depicted Fundamentals? ?of? ?Operations? ? Management? ?4e © The McGrawHill Companies, Inc., 2003 Exhibit 8.6 8–10 Cost Matrix Cost Matrix—Second Solution —Second Solution Fundamentals? ?of? ?Operations? ? Management? ?4e