McGraw-Hill/Irwin Copyright © 2010 by The McGraw-Hill Companies, Inc. All rights reserved. 6 Process Selection and Facility Layout

6-2 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.

6-3 Learning Objectives  List some reasons for redesigning 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.

6-4  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 Introduction

6-5 Forecasting Product and Service Design Technological Change Capacity Planning Process Selection Facilities and Equipment Layout Work Design Figure 6.1 Process Selection and System Design

6-6  Key aspects of process strategy Capital intensive – equipment/labor Process flexibility Technology Adjust to changes – Design – Volume – Technology Process Strategy

6-7 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.

6-8 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

6-9 Technology Competitive Advantage  Innovations in  Products and services  Cell phones  PDAs  Wireless computing  Processing technology  Increasing productivity  Increasing quality  Lowering costs

6-10 Technology Acquisition  Technology can have benefits but …  Technology risks include:  What technology will and will not do  Technical issues  Economic issues  Initial costs, space, cash flow, maintenance  Consultants and/or skilled employees  Integration cost, time resources  Training, safety, job loss

6-11  Variety  How much  Flexibility  What degree  Volume  Expected output Job Shop Batch Repetitive Continuous Process Selection

6-12  Job shop  Small scale  Batch  Moderate volume  Repetitive/assembly line  High volumes of standardized goods or services  Continuous  Very high volumes of non-discrete goods Process Types

Process Type Job Shop Appliance repair Emergency room Ineffective Batch Commercial baking Classroom lecture Repetitive Automotive assembly Automatic carwash Continuous (flow) IneffectiveSteel production Water purification Figure 6.2 Product and Service Processes Low Volume High

6-14 Product and Process Profiling  Process selection can involve substantial investment in  Equipment  Layout of facilities  Product profiling: Linking key product or service requirements to process capabilities  Key dimensions  Range of products or services  Expected order sizes  Pricing strategies  Expected schedule changes  Order winning requirements

6-15  Automation: Machinery that has sensing and control devices that enable it to operate  Fixed automation  Programmable automation Automation

6-16  Computer-aided design and manufacturing systems (CAD/CAM)  Numerically controlled (NC) machines  Robot  Manufacturing cell  Flexible manufacturing systems (FMS)  Computer-integrated manufacturing (CIM) Automation

6-17  Layout: the configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system  Product layouts  Process layouts  Fixed-position layout  Combination layouts Facilities Layout

6-18 Objective of Layout Design 1.Facilitate attainment of product or service quality 2.Use workers and space efficiently 3.Avoid bottlenecks 4.Minimize unnecessary material handling costs 5.Eliminate unnecessary movement of workers or materials 6.Minimize production time or customer service time 7.Design for safety

6-19  Requires substantial investments of money and effort  Involves long-term commitments  Has significant impact on cost and efficiency of short-term operations Importance of Layout Decisions

6-20 Inefficient operations For Example: High Cost Bottlenecks Changes in the design of products or services The introduction of new products or services Accidents Safety hazards The Need for Layout Decisions

6-21 Changes in environmental or other legal requirements Changes in volume of output or mix of products Changes in methods and equipment Morale problems The Need for Layout Design

6-22  Product layouts  Process layouts  Fixed-position layout  Combination layouts Basic Layout Types

6-23  Product layout  Layout that uses standardized processing operations to achieve smooth, rapid, high- volume flow  Process layout  Layout that can handle varied processing requirements  Fixed-position layout  Layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed Basic Layout Types

6-24 Raw materials or customer Finished item Station 2 Station 2 Station 3 Station 3 Station 4 Station 4 Material and/or labor Station 1 Material and/or labor Material and/or labor Material and/or labor Used for Repetitive or Continuous Processing Figure 6.4 Product Layout

6-25  High rate of output  Low unit cost  Labor specialization  Low material handling cost  High utilization of labor and equipment  Established routing and scheduling  Routing accounting and purchasing Advantages of Product Layout

6-26  Creates dull, repetitive jobs  Poorly skilled workers may not maintain equipment or quality of output  Fairly inflexible to changes in volume  Highly susceptible to shutdowns  Needs preventive maintenance  Individual incentive plans are impractical Disadvantages of Product Layout

In Out Workers Figure 6.6 A U-Shaped Production Line

6-28 Dept. A Dept. BDept. D Dept. C Dept. F Dept. E Used for Intermittent Processing Job Shop or Batch Processes Process Layout (functional) Figure 6.7 Process Layout

6-29 Work Station 1 Work Station 2 Work Station 3 Figure 6.7 (cont’d) Product Layout (sequential) Used for Repetitive Processing Repetitive or Continuous Processes Product Layout

6-30  Can handle a variety of processing requirements  Not particularly vulnerable to equipment failures  Equipment used is less costly  Possible to use individual incentive plans Advantages of Process Layouts

6-31  In-process inventory costs can be high  Challenging routing and scheduling  Equipment utilization rates are low  Material handling slow and inefficient  Complexities often reduce span of supervision  Special attention for each product or customer  Accounting and purchasing are more involved Disadvantages of Process Layouts

6-32 Fixed-Position Layouts  Fixed-position Layout: Layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed  Nature of the product dictates this type of layout  Weight  Size  Bulk  Large construction projects

6-33  Cellular Production  Layout in which machines are grouped into a cell that can process items that have similar processing requirements  Group Technology  The grouping into part families of items with similar design or manufacturing characteristics Cellular Layouts

6-34 DimensionFunctionalCellular Number of moves between departments manyfew Travel distanceslongershorter Travel pathsvariablefixed Job waiting timesgreatershorter Throughput timehigherlower Amount of work in process higherlower Supervision difficultyhigherlower Scheduling complexityhigherlower Equipment utilizationlowerhigher Table 6.3 Functional vs. Cellular Layouts

6-35  Warehouse and storage layouts  Retail layouts  Office layouts  Service layouts must be aesthetically pleasing as well as functional Service Layouts

6-36 Line balancing is the process of assigning tasks to workstations in such a way that the workstations have approximately equal time requirements. Design Product Layouts: Line Balancing

6-37 Cycle time is the maximum time allowed at each workstation to complete its set of tasks on a unit. Cycle Time

6-38 Determine Maximum Output

6-39 Determine the Minimum Number of Workstations Required

6-40 Precedence diagram: Tool used in line balancing to display elemental tasks and sequence requirements A Simple Precedence Diagram a b cd e 0.1 min. 0.7 min. 1.0 min. 0.5 min.0.2 min. Figure 6.11 Precedence Diagram

6-41  Arrange tasks shown in Figure 6.11 into three workstations.  Use a cycle time of 1.0 minute  Assign tasks in order of the most number of followers Example 1: Assembly Line Balancing

6-42 Workstation Time RemainingEligible Assign Task Revised Time Remaining Station Idle Time a, c c none ac–ac– bb de–de– de–de– Example 1 Solution

6-43 Efficiency = 1 – Percent idle time Calculate Percent Idle Time

6-44  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. Some Heuristic (intuitive) Rules: Line Balancing Rules

6-45 cd abe fgh Example 2

6-46 Station 1Station 2Station 3Station 4 ab e f d g h c Solution to Example 2

min.2 min.1 min. 30/hr. Bottleneck Bottleneck Workstation

6-48 Parallel Workstations 1 min. 2 min. 1 min. 60/hr. 30/hr. 60/hr. 2 min. 30/hr. Parallel Workstations

6-49 Information Requirements: 1.List of departments 2.Projection of work flows 3.Distance between locations 4.Amount of money to be invested 5.List of special considerations 6.Location of key utilities Designing Process Layouts

ABC Figure 6.13 Example 3: Interdepartmental Work Flows for Assigned Departments

6-51 Process Layout – work travels to dedicated process centers Milling Assembly & Test Grinding Drilling Plating Additional Example: Process Layout

6-52 Gear cutting Mill Drill Lathes Grind Heat treat Assembly Additional Example: Functional Layout

Assembly Lathe Mill Drill Heat treat Heat treat Heat treat Gear cut Gear cut Grind Additional Example: Cellular Manufacturing Layout