Operation management 9e stevenson mcgrwhill chap006

6 Process Selection and Facility Layout McGraw-Hill/Irwin Copyright © 2007 by The McGraw-Hill Companies, Inc All Learning Objectives      Explain the strategic importance of process selection Explain the influence that process selection has on an organization Describe the basic processing types Discuss automated approaches to processing Explain the need for management of technology 6-2 Learning Objectives      List some reasons for redesign of layouts Describe the basic layout types List the main advantages and disadvantages of product layouts and process layouts Solve simple line-balancing problems Develop simple process layouts 6-3 Introduction  Process selection  Deciding on the way production of goods or services will be organized  Major implications     Capacity planning Layout of facilities Equipment Design of work systems 6-4 Figure 6.1 Process Selection and System Design Forecasting Capacity Planning Product and Service Design Technological Change Facilities and Equipment Layout Process Selection Work Design 6-5 Process Strategy • Key aspects of process strategy – Capital intensive – equipment/labor – Process flexibility – Technology – Adjust to changes – Design – Volume – technology 6-6 Technology  Technology: The application of scientific discoveries to the development and improvement of products and services and operations processes  Technology innovation: The discovery and development of new or improved products, services, or processes for producing or providing them 6-7 Kinds of Technology  Operations management is primarily concerned with three kinds of technology:  Product and service technology  Process technology  Information technology  All three have a major impact on:  Costs  Productivity  Competitiveness 6-8 Technology Competitive Advantage  Innovations in  Products and services  Cell phones  PDAs  Wireless computing  Processing technology  Increasing productivity  Increasing quality  Lowering costs 6-9 Technology Acquisition  Technology can have benefits but …  Technology risks include:  What technology will and will not  Technical issues  Economic issues  Initial costs, space, cash flow, maintenance  Consultants and/or skilled employees  Integration cost, time resources  Training, safety, job loss 6-10 Precedence Diagram Figure 6.11 Precedence diagram: Tool used in line balancing to display elemental tasks and sequence requirements 0.1 1.0 a b c 0.7 d 0.5 A Simple Precedence Diagram e 0.2 6-41 Example 1: Assembly Line Balancing  Arrange tasks shown in Figure 6.10 into three workstations   Use a cycle time of 1.0 minute Assign tasks in order of the most number of followers 6-42 Example Solution Eligible Revised Assign Time Task Remaining 1.0 0.9 0.2 a, c c none a c - 0.9 0.2 1.0 b b 0.0 1.0 0.5 0.3 d e - d e - 0.5 0.3 Time Workstation Remaining Station Idle Time 0.2 0.0 0.3 0.5 6-43 Calculate Percent Idle Time Idle time per cycle Percent idle time = (N)(CT) Efficiency = – Percent idle time 6-44 Line Balancing Rules Some Heuristic (intuitive) Rules:  Assign tasks in order of most following tasks  Count the number of tasks that follow  Assign tasks in order of greatest positional weight  Positional weight is the sum of each task’s time and the times of all following tasks 6-45 Example 0.2 0.2 0.3 a b e 0.8 0.6 c d f g h 1.0 0.4 0.3 6-46 Solution to Example Station a b Station Station e f c Station g h d 6-47 Bottleneck Workstation 30/hr 30/hr 30/hr 30/hr Bottleneck 6-48 Parallel Workstations 30/hr 60/hr 30/hr min 60/hr 30/hr 30/hr Parallel Workstations 6-49 Designing Process Layouts Information Requirements: List of departments Projection of work flows Distance between locations Amount of money to be invested List of special considerations Location of key utilities 6-50 Example 3: Interdepartmental Work Flows Figure 6.13 for Assigned Departments 30 A 170 B 100 C 6-51  PowerPoint Author’s note:  The following three slides are not in the 9e text, but I like to use them for alternate examples 6-52 Process Layout Milling Assembly & Test Grinding Drilling Plating Process Layout - work travels to dedicated process centers 6-53 Functional Layout 111 3333 Assembly 44 33 Lathes Heat treat Grind 44 33 111 333 1111 2222 33 111 333 Drill 222 Mill 222 33 444 222 111 444 333 222 Gear cutting 111 444 6-54 -1111 Lathe 222222222 3333333333 Mill Mill Drill Drill Lathe Mill 44444444444444 Mill Heat treat Gear -1111 cut Heat treat Grind - 2222 Heat treat Grind - 3333 Drill Gear - 4444 cut Assembly Cellular Manufacturing Layout 6-55 ... and operations processes  Technology innovation: The discovery and development of new or improved products, services, or processes for producing or providing them 6-7 Kinds of Technology  Operations... commitments  Has significant impact on cost and efficiency of short-term operations 6-20 The Need for Layout Decisions Inefficient operations For Example: High Cost Bottlenecks Changes in the design... products, services, or processes for producing or providing them 6-7 Kinds of Technology  Operations management is primarily concerned with three kinds of technology:  Product and service technology