© 1997 Prentice-Hall, Inc. Principles of Operations Management Process & Capacity Design Chapter 5 5-1 Learning Objectives © 1997 Prentice-Hall, Inc. Describe the types of process strategies Compare technological alternatives State how to select a process strategy Define capacity Explain how to manage existing capacity 5-2 Thinking Challenge © 1997 Prentice-Hall, Inc. Consider McDonald’s restaurants. Fact #1: Franchisees of McDonald’s have to go to ‘Hamburger U.’ They protest, ‘But, I’ve been in the restaurant business 20 years – I know the restaurant business!’ ‘Yes, but you don’t know OUR business.’ 5-3 McDonald’s over 95 billion served © 1984-1994 T/Maker Co. Thinking Challenge © 1997 Prentice-Hall, Inc. Fact #2: A typical McDonald’s restaurant is run by unskilled teenagers, whose mothers can’t even get them to make their beds in the morning. What do these facts & your own experiences suggest about McDonald’s operations? 5-4 Alone Group Class McDonald’s over 95 billion served © 1984-1994 T/Maker Co. Process Decisions © 1997 Prentice-Hall, Inc. Involve determining how to produce a product or provide a service Objective Meet or exceed customer requirements Meet cost & managerial goals Has long-run effects Product & volume flexibility Costs & quality 5-5 © 1997 Prentice-Hall, Inc. Types of Process Strategies The strategies are often classified as: ProcessRepetitiveProductFocused Focused Focused Continuum 5-6 Process-Focused Strategy © 1997 Prentice-Hall, Inc. Facilities are organized by process Similar processes are together Example: All drill presses are together Low volume, high variety products ‘Jumbled’ flow Other names Intermittent process Job shop 5-7 Product A Oper. 1 2 Product B 3 Process-Focused Strategy Pros © 1997 Prentice-Hall, Inc. Advantages & Cons Greater product flexibility More general purpose equipment Lower initial capital investment Disadvantages More highly trained personnel More difficult production planning & control Low equipment utilization (5% to 25%) 5-8 Product-Focused Strategy © 1997 Prentice-Hall, Inc. Facilities are organized by product High volume, low variety products Other names Products A & B Line flow production Oper. 1 Continuous production 2 Where found Discrete unit manufacturing Continuous process manufacturing 5-9 3 Product-Focused Strategy © 1997 Prentice-Hall, Inc. Advantages Pros & Cons Lower variable cost per unit Lower but more specialized labor skills Easier production planning & control Higher equipment utilization (70% to 90%) Disadvantages Lower product flexibility More specialized equipment Usually higher capital investment 5 - 10 © 1997 Prentice-Hall, Inc. Repetitive-Focused Strategy Facilities often organized by assembly lines Characterized by modules Parts & assemblies made previously Modules combined for many output options Other names Assembly line Production line 5 - 11 © 1997 Prentice-Hall, Inc. Thinking Challenge: Compare & Contrast Process Strategy Basis of Comparison 5 - 12 Alone Group Class Technology Alternatives © 1997 Prentice-Hall, Inc. General purpose machines Numerical control machines Process control Robots Automated guided vehicles (AGV) Flexible manufacturing systems (FMS) Computer-integrated mfg. (CIM) 5 - 13 © 1997 Prentice-Hall, Inc. General Purpose Machines (GPM) Machines capable of performing many different operations Manually operated Found in processfocused facilities Low volume production 5 - 14 Manual Lathe © 1995 Corel Corp. Router © 1995 Corel Corp. Numerical Control (NC) © 1997 Prentice-Hall, Inc. Used in computeraided mfg. (CAM) Using computers to program, direct, & control machines Numerical control (NC) machine Repeat operations by reading punch paper or magnetic tape 5 - 15 Computer numerical control (CNC) machine Programmable by operator at machine Has own memory Direct numerical control (DNC) machine Has own memory Connected to computer running many machines Process Control © 1997 Prentice-Hall, Inc. Use of information technology to control physical process Example: Measure thickness of wallboard Found in product & repetitive-focused facilities 5 - 16 Actual avg. Planned avg. Process limits © 1995 Corel Corp. Robots © 1997 Prentice-Hall, Inc. Machines that hold, move, or grasp items Perform monotonous or dangerous tasks Used when speed, accuracy, or strength are needed 5 - 17 © 1984-1994 T/Maker Co. © 1997 Prentice-Hall, Inc. Automated Guided Vehicles (AGV) Material handling machines © 1984-1994 T/Maker Co. Used to move parts & equipment in manufacturing May be used to deliver mail & meals in service facilities 5 - 18 © 1997 Prentice-Hall, Inc. Flexible Manufacturing Systems (FMS) Using automated machines (DNC) & materials handling equipment together Often connected to centralized computer Also called automated work cell Auto Tool Chg. Machine 1 Robot or AGV Computer Auto Tool Chg. Machine 2 5 - 19 © 1997 Prentice-Hall, Inc. Computer-Integrated Manufacture (CIM) Mfg. system that combines CAM with engineering (CAD), & production & inventory control Computer-aided design (CAD) creates code to run DNC machines Top Mgmt CAD PIC DNC Robots AGV CAM 5 - 20 Production Process & Technology Alternatives © 1997 Prentice-Hall, Inc. # Different Products or Parts High General Purpose, NC, CNC CIM Flexible Mfg. System Low Low 5 - 21 Dedicated Automation High Volume of Products or Parts © 1997 Prentice-Hall, Inc. Production flexibility Factors Affecting Process Alternatives Product volume Product variety These factors reduce the number of alternatives! Technology Cost Human resources Quality Reliability 5 - 22 © 1984-1994 T/Maker Co. © 1997 Prentice-Hall, Inc. Long-term factors Process Investment Evaluation Fit with company strategic plan Competitive advantage Product life cycle Operating factors (e.g., scrap, training) Financial return Break-even analysis Cash flow analysis (IRR, NPV) 5 - 23 Break-Even Analysis © 1997 Prentice-Hall, Inc. Technique for evaluating process & equipment alternatives Objective: Find the point ($ or units) at which total cost equals total revenue Assumptions Revenue & costs are related linearly to volume All information is known with certainty No time value of money 5 - 24 Facility Planning © 1997 Prentice-Hall, Inc. Facility planning answers: How much long-range capacity is needed When more capacity is needed Where facilities should be located (location) How facilities should be arranged (layout) 5 - 25 Capacity © 1997 Prentice-Hall, Inc. Maximum output of a system in a given period (general definition) May be units, hours, dollars, sq. ft. etc. Example: Tons of steel per month Effective capacity: Maximum output given standards, product mix, etc. Rated capacity: Maximum usable output given utilization & efficiency RC = (Capacity)(Utilization)(Efficiency) 5 - 26 © 1997 Prentice-Hall, Inc. Capacity Definition Thinking Challenge How would you define capacity for the following firms (e.g., steel mill, tons of steel per day): Beer brewery Auto plant Restaurant Warehouse Grocery store 5 - 27 Alone Group Class Utilization © 1997 Prentice-Hall, Inc. Measure of planned or actual capacity usage of a facility, work center, or machine Utilization 5 - 28 Expected capacity Capacity Planned hours to be used Total hours available Efficiency © 1997 Prentice-Hall, Inc. Measure of how well a facility or machine is performing when used Efficiency 5 - 29 Actual output Effective capacity Actual output in units Standard output in units Average actual time Standard time Utilization Example © 1997 Prentice-Hall, Inc. You’re owner of a small florist shop. Normally, your shop is open 8 hr./day Monday to Friday, & 4 hr. on Saturday. During the summer, you’re closed on Monday & Saturday. What is your capacity, expected capacity, & utilization during the summer? 5 - 30 © 1995 Corel Corp. © 1997 Prentice-Hall, Inc. Utilization Thinking Challenge © 1984-1994 T/Maker Co. You’re operations manager of a paper company. Given the expensive machinery, full capacity is 3 shifts, 7 days per week. Since demand is slow, you’ve scheduled 3 shifts, 6 days per week. What is your capacity, expected capacity, & utilization? © 1995 Corel Corp. 5 - 31 Alone Group Class © 1997 Prentice-Hall, Inc. Rated Capacity Thinking Challenge © 1984-1994 T/Maker Co. The standard rate of output of a paper mfg. machine is 1800 ft./min. Records show that the actual average rate is 1710 ft./min. Present utilization is 85.7%. The plant was designed to make 92,000 tons of paper per year. What is the rated capacity? © 1995 Corel Corp. 5 - 32 Alone Group Class © 1997 Prentice-Hall, Inc. Capacity Planning Process Forecast Demand Develop Alternative Plans Quantitative Factors (e.g., Cost) Compute Rated Capacity Evaluate Capacity Plans Qualitative Factors (e.g., Skills) Compute Needed Capacity Select Best Capacity Plan 5 - 33 Implement Best Plan © 1997 Prentice-Hall, Inc. Managing Existing Capacity Demand Management Capacity Management Vary prices Vary staffing Vary promotion Change lead times (e.g., backorders) Change equipment & processes Change methods Redesign the product for faster processing Offer complementary products 5 - 34 Conclusion © 1997 Prentice-Hall, Inc. Described the types of process strategies Compared technological alternatives Stated how to select a process strategy Defined capacity Explained how to manage existing capacity 5 - 35