OM2 CHAPTER 10 CAPACITY MANAGEMENT DAVID A. COLLIER AND JAMES R. EVANS OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 1 Chapter 10 Learning Outcomes learning outcomes LO1 Explain the concept of capacity. LO2 Describe how to compute and use capacity measures. LO3 Describe long-term capacity expansion strategies. LO4 Describe short-term capacity adjustment strategies. LO5 Explain the principles and logic of the Theory of Constraints. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 2 Chapter 10 Capacity Management If there’s a downside to selling a product users can’t live without, it’s that customers tend to be unforgiving when something goes wrong. That’s a lesson BlackBerry maker Research In Motion (RIM) Ltd., based in Waterloo, Ontario, learned in 2008 after the company’s popular wireless email service failed for about three hours – the second large-scale service disruption in less than a year – leaving so-called “Crackberry addict”" running for their desktop computers to read messages. Reports suggested the outage was related to RIM’s efforts to expand capacity at its central operating center as its subscriber base increased at the rate of one million new users every three months. (continued) OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 3 Chapter 10 Capacity Management Critics argue that RIM is more susceptible to major service failures because of its centralized network architecture. RIM designs servers that relay email from a company’s own server to a network operating center, where it is then handed off to a wireless carrier and beamed to a subscriber’s device. The advantage of such a centralized setup is that it gives RIM more control over the system and its security, even during an interruption. The downside, however, is that a major problem at the operating center such as inadequate server and backup capacity threatens to cascade throughout the entire system, turning a localized issue into a continent-wide mess. What do you think? Have you ever experienced problems with a service because of inadequate labor or equipment capacity? OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 4 Chapter 10 Capacity Management Understanding Capacity Capacity is the capability of a manufacturing or service resource such as a facility, process, workstation, or piece of equipment to accomplish its purpose over a specified time period. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 5 Chapter 10 Capacity Management Understanding Capacity The resources available to the organization—facilities, equipment, and labor—how they are organized, and their efficiency as determined by specific work methods and procedures determine capacity. Capacity can be viewed in one of two ways: 1. As the maximum rate of output per unit of time, or 2. As units of resource availability. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 6 Chapter 10 Capacity Management Solved Problem An automobile transmission-assembly factory normally operates two shifts per day, five days per week. During each shift, 400 transmissions can be completed under ideal conditions. What is the capacity of this factory? Capacity = (2 shifts/day)(5 days/week) (400 tranmissions/shift)(4 weeks/month) = 16,000 transmissions/month OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 7 Chapter 10 Capacity Management Key Capacity Issues • Can the facility, process, or equipment accommodate new goods and services and adapt to changing demand for existing goods and services? • How large should facility, process, or equipment capacity be? • When should capacity changes take place? OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 8 Exhibit 10.1 Examples of Short- and Long-Term Capacity Decisions OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 9 Chapter 10 Capacity Management Understanding Capacity Economies of scale are achieved when the average unit cost of a good or service decreases as the capacity and/or volume of throughput increases. Diseconomies of scale occur when the average unit cost of the good or service begins to increase as the capacity and/or volume of throughput increases. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 10 Chapter 10 Capacity Management Understanding Capacity A focused factory is a way to achieve economies of scale without extensive investments in facilities and capacity by focusing on a narrow range of goods or services, target market segments, and/or dedicated processes to maximize efficiency and effectiveness. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 11 Chapter 10 Capacity Management Understanding Capacity Safety capacity (often called the capacity cushion) is an amount of capacity reserved for unanticipated events, such as demand surges, materials shortages, and equipment breakdowns. Average safety capacity (%) = 100% − Average resource utilization % [10.1] OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 12 Exhibit 10.2 The Demand versus Capacity Problem Structure OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 13 Chapter 10 Capacity Management Capacity Measurement in Job Shops • In a job shop, setup time can be a substantial part of total system capacity. Capacity Required (Ci) = Setup Time (Si) + [Processing Time (Pi) x Order Size (Qi)] = Si + [(Pi)(Qi )] OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. [10.2] 14 Chapter 10 Capacity Management Solved Problem • Ham’s Dental Office (Exhibits 10.3 and 10.4) illustrates these calculations using a dental procedure mix. • Setup times normally represent a substantial percentage of the total capacity of most job shops. Every effort must be made to reduce setup time to the lowest possible amount so as to “free up capacity” for creating output. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 15 Exhibit 10.3 Dental Office Procedures and Times for Today OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 16 Exhibit 10.4 *Example Dental Office Demand-Capacity Analysis computation: C = Si + Pi × Qi) = 15 + 15 + (90 × 2) = 210 minutes, assuming a setup for each patient. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 17 Chapter 10 Capacity Management Long-Term Capacity Strategies • In developing a long-range capacity plan, a firm must make the basic economic trade-off between the cost of capacity and the opportunity cost of not having adequate capacity. • Long-term capacity planning must be closely tied to the strategic direction of the organization—what products and services it offers. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 18 Chapter 10 Long-Term Capacity Strategies Long-Term Capacity Strategies • Complementary goods and services can be produced or delivered using the same resources available to the firm, but whose seasonal demand patterns are out of phase with each other. • Complementary goods or services balance seasonal demand cycles and therefore use the excess capacity available, as illustrated in Exhibit 10.5. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 19 Exhibit 10.5 Seasonal Demand and Complementary Goods or Services OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 20 Chapter 10 Capacity Management Briggs and Stratton Briggs & Stratton is the world’s largest producer of aircooled gasoline engines for outdoor power equipment. The company designs, manufacturers, markets, and services these products for original equipment manufacturers worldwide. These engines are primarily aluminum alloy gasoline engines ranging from 3 through 25 horsepower. Briggs & Stratton is a leading designer, manufacturer, and marketer of portable generators, lawn mowers, snow throwers, pressure washers, and related accessories. It also provides engines for manufacturers of other small engine-driven equipment such as snowmobiles, go-karting, and jet skis. (continued) OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 21 Chapter 10 Capacity Management Briggs and Stratton The complementary and diverse original equipment markets for Briggs & Stratton engines allows factory managers to plan equipment and labor capacities and schedules in a much more stable operating environment. This helps minimize manufacturing costs, stabilize workforce levels, and even out volumes so that assembly lines can be used in a more efficient fashion OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 22 Chapter 10 Capacity Expansion Options Long-Term Capacity Strategies Four basic strategies for expanding capacity over some fixed time horizon: 1. One large capacity increase (Exhibit 10.6a). 2. Small capacity increases that match average demand (Exhibit 10.6b). 3. Small capacity increases that lead demand (Exhibit 10.6c). 4. Small capacity increases that lag demand (Exhibit 10.6d). OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 23 Exhibit 10.6 OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Capacity Expansion Options 24 Chapter 10 Capacity Management Short Term Capacity Adjustment Decisions • • • • • Add or share equipment: lease equipment as needed or set up a partnership arrangement with capacity sharing. Examples: mainframe computers, CAT scanner, farm equipment. Sell unused capacity: sell idle capacity to outside buyers and even competitors. Examples: computing capacity, perishable hotel rooms. Change labor capacity and schedules: short term changes in work force levels. Examples: overtime, extra shifts, temporary employees, outsourcing. Change labor skill mix: hiring the right people. Shift work to slack periods OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 25 Chapter 10 Capacity Management Managing Capacity by Shifting and Stimulating Demand • • • • • Vary the price of goods or services: price is the most powerful way to influence demand. Provide customers information: best times to call or visit. Advertising and promotion: a vital role on influencing demand; promotions are strategically distributed to increase demand during periods of low sales or excess capacity. Add peripheral goods and/or services: change demand during slack periods. Provide reservations: a promise to provide a good or service at some future time and place. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 26 Chapter 10 Capacity Management If You Make a Reservation, Be Sure to Show Up! The following sign was seen on a doctor’s reception desk: NO-SHOW POLICY Beginning August 15, 2008 we will be charging a $30 fee to patients who fail to keep their scheduled appointments. To avoid this fee, patients need to cancel their appointment 24 hours ahead. This fee is not covered by insurance and will be the patient’s responsibility. What does this statement demonstrate about the nature of service demand and capacity? OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 27 Chapter 10 Capacity Management Revenue Management Systems A revenue management system (RMS) - often called yield management - consists of dynamic methods to forecast demand, allocate perishable assets across market segments, decide when to overbook and by how much, and determine what price to charge different customer (price) classes. Revenue management systems consist of forecasting, allocation, overbooking, and pricing. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 28 Chapter 10 Capacity Management Theory of Constraints The Theory of Constraints (TOC) is a set of principles that focuses on increasing total process throughput by maximizing the utilization of all bottleneck work activities and workstations. • Throughput: amount of money generated per time period through actual sales. • Constraint: anything that limits an organization from moving toward or achieving its goal. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 29 Chapter 10 Capacity Management Theory of Constraints • A physical constraint is associated with the capacity of a resource (e.g., machine, employee). • A bottleneck work activity is one that effectively limits capacity of the entire process. • A nonbottleneck work activity is one in which idle capacity exists. • A nonphysical constraint is environmental or organizational (e.g., low product demand or an inefficient management policy or procedure). OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 30 Exhibit 10.7 Basic Principles of the Theory of Constraints OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 31 Chapter 10 Capacity Management David Christopher, Orthopedic Surgeon, Case Study 1. What is the clinic’s current weekly workload? 2. Should the clinic hire more surgeons, and if so, how many? 3. What other options and changes could be made to maximize patient throughput and surgeries, and therefore revenue, yet not comprise on the quality of medical care? 4. What are your final recommendations? Explain your reasoning. OM2, Ch. 10 Capacity Management ©2010 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 32