Stevenson 13e Chapter 6 Process Selection and Facility Layout PDF

Chapter 6 Process Selection and Facility Layout Copyrigh...

Chapter 6 Process Selection and Facility Layout Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 6-1 Chapter 6: Learning Objectives You should be able to: LO 6.1 Explain the strategic importance of process selection and the influence it has on the organization and its supply chain LO 6.2 Name the two main factors that influence process selection LO 6.3 Compare the four basic processing types LO 6.4 Explain the need for management of technology LO 6.5 List some reasons for redesign of layouts LO 6.6 Describe product layouts and their main advantages and disadvantages LO 6.7 Describe process layouts and their main advantages and disadvantages LO 6.8 Solve simple line-balancing problems LO 6.9 ©2018 Copyright Develop simple McGraw-Hill process Higher Education. layouts All rights reserved. No reproduction or distribution 6-2 without the prior written consent of McGraw-Hill Education Process Selection Process selection  Refers to deciding on the way production of goods or services will be organized  It has major implications for Capacity planning Layout of facilities Equipment Design of work systems LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-3 distribution without the prior written consent of McGraw-Hill Education 6.1 Process Selection and System Design Facilities and Forecasting Capacity Equipment Planning Product and Layout Service Design Process Technological Selection Work Change Design LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-4 distribution without the prior written consent of McGraw-Hill Education 6.1 Process Strategy  Key aspects of process strategy:  Capital intensity  The mix of equipment and labor that will be used by the organization  Process flexibility  The degree to which the system can be adjusted to changes in processing requirements due to such factors as  Product and service design changes  Volume changes  Changes in technology LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-5 6.1 distribution without the prior written consent of McGraw-Hill Education Process Selection Two key questions in process selection: 1. How much variety will the process need to be able to handle? 2. How much volume will the process need to be able to handle? Job Shop Batch Continuou Repetitive s LO 6-6 Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6.2 distribution without the prior written consent of McGraw-Hill Education Types of Processing Repetitive/ Continuou Job Shop Batch Assembly s Description Customized Semi- Standardized Highly goods or standardized goods or standardized services goods or services Goods or services services Advantages Able to handle a Flexibility; easy Low unit Very efficient, very wide variety to add or cost, high high volume of work change volume, products or efficient services Disadvantage Slow, high cost Moderate cost Low flexibility, Very rigid, lack of s per unit, per unit, high cost of variety, costly complex moderate downtime to change, very planning and scheduling high cost of scheduling complexity downtime LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-7 6.3 distribution without the prior written consent of McGraw-Hill Education Sustainable Production of Goods and Services There is increasing pressure for organizations to operate sustainable production processes According to the Lowell Center for Sustainable Production:  “Sustainable Production is the creation of goods and services using processes and systems that are: non-polluting; conserving of energy and natural resources; economically efficient; safe and healthful for workers, communities, and consumers; and, socially and creatively rewarding for all working people.” Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-8 distribution without the prior written consent of McGraw-Hill Education Process and Information Technology  Process and information technology can have a major impact on costs, productivity and competitiveness:  Process technology  Methods, procedures, and equipment used to produce goods and provide services  Information technology  The science and use of computers and other electronic equipment to store, process, and send information Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution 6-9 without the prior written consent of McGraw-Hill Education The Need to Manage Technology Process technology and information technology can have a profound impact on:  Costs  Productivity  Competitiveness LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-10 distribution without the prior written consent of McGraw-Hill Education 6.4 Automation Automation  Machinery that has sensing and control devices that enable it to operate automatically Fixed automation Programmable automation Flexible automation Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution 6-11 without the prior written consent of McGraw-Hill Education Programmable Automation  Programmable automation  Involves the use of high-cost, general-purpose equipment controlled by a computer program that provides both the sequence of operations and specific details about each operation  Computer-Aided Manufacturing (CAM)  The use of computers in process control, ranging from robots to automated quality control  Numerically Controlled (N/C) Machines  Machines that perform operations by following mathematical processing instructions  Robot  A machine consisting of a mechanical arm, a power supply, and a controller Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-12 distribution without the prior written consent of McGraw-Hill Education Flexible Automation  Flexible automation  Evolved from programmable automation. It uses equipment that is more customized than that of programmable automation. A key difference between the two is that flexible automation requires significantly less changeover time.  FMS (Flexible Manufacturing System)  A group of machines designed to handle intermittent processing requirements and produce a variety of similar products  CIM (Computer Integrated Manufacturing)  A system for linking a broad range of manufacturing activities through an integrated computer system Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-13 distribution without the prior written consent of McGraw-Hill Education Flexible Manufacturing System (FMS) FMS  A group of machines designed to handle intermittent processing requirements and produce a variety of similar products Have some of the benefits of automation and some of the flexibility of individual, or stand-alone, machines Includes supervisory computer control, automatic material handling, and robots or other automated processing equipment Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution 6-14 without the prior written consent of McGraw-Hill Education Computer Integrated Manufacturing (CIM)  CIM  A system for linking a broad range of manufacturing activities through an integrated computer system  Activities include  Engineering design  FMS  Purchasing  Order processing  Production planning and control  The overall goal of CIM is to link various parts of an organization to achieve rapid response to customer orders and/or product changes, to allow rapid production and to reduce indirect labor costs Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution 6-15 without the prior written consent of McGraw-Hill Education Facilities Layout Layout  The configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system  Facilities layout decisions arise when: Designing new facilities Re-designing existing facilities Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 6-16 The Need for Layout Planning 1. Inefficient operations  High cost  Bottlenecks 2. Accidents or safety hazards 3. Changes in product or service design 4. Introduction of new products or services 5. Changes in output volume or product mix 6. Changes in methods or equipment 7. Changes in environmental or other legal requirements 8. Morale problems LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-17 distribution without the prior written consent of McGraw-Hill Education 6.5 Layout Design Objectives  Basic objective  Facilitate a smooth flow of work, material, and information through the system  Supporting objectives 1. Facilitate product or service quality 2. Use workers and space efficiently 3. Avoid bottlenecks 4. Minimize material handling costs 5. Eliminate unnecessary movement of workers or material 6. Minimize production time or customer service time 7. Design for safety LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-18 distribution without the prior written consent of McGraw-Hill Education 6.5 Basic Layout Types Product layouts Process layouts Fixed-position layout Combination layouts Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution 6-19 without the prior written consent of McGraw-Hill Education Repetitive Processing: Product Layouts Product layout  Layout that uses standardized processing operations to achieve smooth, rapid, high- volume flow Raw materials Station Station Station Station Finished or customer item 1 2 3 4 Material Material Material Material and/or and/or and/or and/or labor labor labor labor Used for Repetitive Processing Repetitive or Continuous LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-20 distribution without the prior written consent of McGraw-Hill Education 6.6 Product Layouts: Advantages & Disadvantages Advantages Disadvantages  Creates dull, repetitive jobs  High rate of output  Poorly skilled workers may not  Low unit cost maintain equipment or quality  Labor specialization of output  Low material handling cost  Fairly inflexible to changes in per unit volume or product or process design  High utilization of labor and  Highly susceptible to equipment shutdowns  Established routing and  Preventive maintenance, scheduling capacity for quick repair and spare-parts inventories are  Routine accounting, necessary expenses purchasing, and inventory  Individual incentive plans are control impractical LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-21 distribution without the prior written consent of McGraw-Hill Education 6.6 Non-repetitive Processing: Process Layouts Process layouts  Layouts that can handle varied processing requirements Dept. A Dept. C Dept. E Dept. B Dept. D Dept. F Used for Intermittent processing LO Job Shop or Batch 6-22 Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6.7 distribution without the prior written consent of McGraw-Hill Education Process Layouts: Advantages & Disadvantages Advantages Disadvantages  Can handle a variety of  In-process inventories can be high processing requirements  Routing and scheduling pose  Not particularly vulnerable continual challenges to equipment failures  Equipment utilization rates are  General-purpose low equipment is often less  Material handling is slow and costly and easier and less inefficient costly to maintain  Reduced spans of supervision  It is possible to use  Special attention necessary for individual incentive each product or customer  Accounting, inventory control, systems and purchasing are more involved LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-23 distribution without the prior written consent of McGraw-Hill Education 6.7 Fixed Position Layouts Fixed position layout  Layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution 6-24 without the prior written consent of McGraw-Hill Education Combination Layouts  Some operational environments use a combination of the three basic layout types:  Hospitals  Supermarket  Shipyards  Some organizations are moving away from process layouts in an effort to capture the benefits of product layouts  Cellular manufacturing  Flexible manufacturing systems Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution 6-25 without the prior written consent of McGraw-Hill Education Service Layouts  Service layouts can be categorized as: product, process, or fixed position  Service layout requirements are somewhat different due to such factors as:  Degree of customer contact  Degree of customization  Common service layouts:  Warehouse and storage layouts  Retail layouts  Office layouts Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education 6-26 Cellular Layouts Cellular production  Layout in which workstations are grouped into a cell that can process items that have similar processing requirements Groupings are determined by the operations needed to perform the work for a set of similar items, part families, that require similar processing The cells become, in effect, miniature versions of product layouts Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution 6-27 without the prior written consent of McGraw-Hill Education Group Technology Group technology  The grouping into part families of items with similar design or manufacturing characteristics Design characteristics:  Size  Shape  Function Manufacturing or processing characteristics  Type of operations required  Sequence of operations required  Requires a systematic analysis of parts to identify the part families Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution 6-28 without the prior written consent of McGraw-Hill Education Service Layouts Two key factors:  Customer contact  Degree of customization Layouts:  Warehouse and storage layouts  Retail layouts  Office layouts Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or distribution 6-29 without the prior written consent of McGraw-Hill Education Designing Product Layouts: Line Balancing  The goal of a product layout is to arrange workers or machines in the sequence that operations need to be performed LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-30 distribution without the prior written consent of McGraw-Hill Education 6.8 Line Balancing Line balancing  The process of assigning tasks to workstations in such a way that the workstations have approximately equal time requirements  Goal:  Obtain task grouping that represent approximately equal time requirements since this minimizes idle time along the line and results in a high utilization of equipment and labor  Why is line balancing important? 1. It allows us to use labor and equipment more efficiently 2. To avoid fairness issues that arise when one workstation must work harder than another LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-31 6.8 distribution without the prior written consent of McGraw-Hill Education Cycle Time Cycle time  The maximum time allowed at each workstation to complete its set of tasks on a unit  Cycle time also establishes the output rate of a line Cycle time Operating time per day Desired output rate Operating time per day Output rate  Cycle time LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-32 distribution without the prior written consent of McGraw-Hill Education 6.8 How Many Workstations Are Needed? The required number of workstations is a function of  Desired output rate  Our ability to combine tasks into a workstation Theoretical minimum number of stations N min  t Cycle time where N min theoretical minimum number of stations  t Sum of task times LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-33 6.8 distribution without the prior written consent of McGraw-Hill Education Precedence Diagram  Precedence diagram  A diagram that shows elemental tasks and their precedence requirements LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-34 distribution without the prior written consent of McGraw-Hill Education 6.8 Assigning Tasks to Workstations 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  Positionalweight is the sum of each task’s time and the times of all following tasks LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-35 distribution without the prior written consent of McGraw-Hill Education 6.8 Measuring Effectiveness  Balance delay (percentage of idle time)  Percentage of idle time of a line Idle time per cycle Balance Delay  100 N actual Cycle time where N actual Actual number of stations  Efficiency  Percentage of busy time of a line Efficiency 100% - Balance Delay LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-36 distribution without the prior written consent of McGraw-Hill Education 6.8 Designing Process Layouts The main issue in designing process layouts concerns the relative placement of the departments Measuring effectiveness  A major objective in designing process layouts is to minimize transportation cost, distance, or time LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-37 6.9 distribution without the prior written consent of McGraw-Hill Education Information Requirements  In designing process layouts, the following information is required: 1. A list of departments to be arranged and their dimensions 2. A projection of future work flows between the pairs of work centers 3. The distance between locations and the cost per unit of distance to move loads between them 4. The amount of money to be invested in the layout 5. A list of any special considerations 6. The location of key utilities, access and exit points, etc. LO Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6-38 distribution without the prior written consent of McGraw-Hill Education 6.9 Process Layout Problem Distance between locations in meters To A B C A 20 40 From B 30 C Interdepartmental work flows (loads per day) To 1 2 3 1 30 170 From 2 100 3 LO 6-39 Copyright ©2018 McGraw-Hill Higher Education. All rights reserved. No reproduction or 6.9 distribution without the prior written consent of McGraw-Hill Education Process Layout Problem (cont.) 30 170 100 1 2 3 A B C Dept. Load Locatio Distanc Load s n e Distance (meters Score ) 1 to 2 170 A to B 20 170 x 20 = 3,400 1 to 3 30 A to C 40 30 x 40 = 1,200 2 to 3 100 B to C 30 100 x 30 = LO Copyright ©2018 McGraw-Hill Higher Education. All rights 3,000 reserved. No reproduction or 6-40 6.9 distribution without the prior written consent of McGraw-Hill Education