Chapter 1 Operations and Productivity DISCUSSION QUESTIONS1.Why should one study operations management?SOLUTIONThe text suggests four reasons to study OM. We want to understand(1) how people organize themselves for productive enterprise,(2) how goods and services are produced, (3) what operationsmanagers do, and (4) this costly part of our economy and mostenterprises.6.What are the three basic functions of a firm?SOLUTIONThe basic functions of a firm are marketing, accounting/fi nance, and operations. An interesting class discussion: “Do allfirms/organizations (private, government, not-for-profit) performthese three functions?” The authors’ hypothesis is yes, they do. the 10 decision areas of operations management.SOLUTION1.Design of Goods and Services.2.Managing Quality.3.Process Strategy.4.Location Strategies.yout Strategies.6.Human Resources.7.Supply-Chain Management.8.Inventory Management.9.Scheduling.10.Maintenance.13.Describe some of the actions taken by Taco Bell to increase productivity thathave resulted in Taco Bell’s ability to serve “twice the volume with half the labor.”SOLUTIONTaco Bell designed meals that were easy to prepare; withactual cooking and food preparation done elsewhere; automationto save preparation time; reduced floor space; manager training toincrease span of control.PROBLEMS1.1John Lucy makes wooden boxes in which to ship motorcycles. John and histhree employees invest 40 hours per day making the 120 boxes.a)What is their productivity?b)John and his employees have discussed redesigning the process to improvethe productivity. If they can increase the rate to 125 per day, what will betheir new productivity?c)What will be their increase in productivity?SOLUTION(a)= 3.0 boxes/hour(b)= 3.125 boxes/hour(c)Change in productivity = 0.125 boxes/hour(d)Percentage change = = 4.166%1.6 Eric Johnson makes billiard balls in his New England plant. With recentincreases in his costs, he has a newfound interest in efficiency. Eric isinterested in determining the productivity of his organization. He would like to know if his organization is maintaining the manufacturing average of 3% increase in productivity. He has the following data representing a month from last year and an equivalent month this year:LAST YEAR NOWUnits produced 1,000 1,000Labor (hours) 300 275Resin (pounds) 50 45Capital invested ($) 10,000 11,000Energy (BTU) 3,000 2,850 Show the productivity change for each category and then determine theimprovement for labor-hours, the typical standard for compassion.SOLUTIONResource Last Year This Year Change Percent ChangeLabor =3.33 =3.64 0.31 =9.3%Resin =20 =22.22 2.22 =11.1%Capital =0.1 =0.09 -0.01 =-10.0%Energy =0.33 =0.35 0.02 =6.1%1.7 Eric Johnson (using data from Problem 1.6) determines his costs to be asfollows:·labor $10 per hour;·resin $5 per pound;·capital 1% per month of investment;·energy $.50 per BTU.Show the productivity change, for one month last year versus one month this year, on a multifactor basis with dollars as the common denominator.SOLUTIONLast Year This YearProduction 1,000 1,000Labor hr. @ $10 $3,000 $2,750Resin @ $5 250 225Capital cost/month 100 110Energy 1,500 1,425$4,850 $4,510= = = 0.078 fewer resources=>7.8% improvement* * with rounding to 3 decimal places.Chapter 2 Operations Strategy in a GlobalEnvironment P42DISCUSSION QUESTIONS6.Describe how an organization’s mission（使命） and strategy(战略) have different purposes.Solution:A mission specifies where the organization is going and a Strategy specifies how it is going to get there.10.There are three primary ways to achieve competitive advantage. Provide an example, not include in the text, of each. Support your choices.Solution:The text focuses on three conceptual strategies—cost leadership, differentiation and response. Cost leadership by Wal-Mart—via low overhead, vicious cost reduction in the supply chain; Differentiation, certainly any premium product—all fine dining restaurants, up-scale autos—Lexus, etc.; Response, your local pizza delivery service, FedEx, etc.12. Given the discussion of Southwest Airlines in the test, define an operations strategy(运营战略) for that firm.Solution:The integration of OM with marketing and accounting is pervasive. You might want to cite examples such as developing new products. (Marketing must help with the design, the forecast and target costs; accounting must ensure adequate cash for development and the necessary capital equipment.) Similarly, new technology or new processes emanating from operations must meet the approval of marketing and the capital constraints imposed by the accounting department.PROBLEMS2.1 The test provides three primary ways--strategic approaches—for achieving competitive advantage. Provide an example of each not provided in the test. Support your choices. (Hint: Note the example provided in the test.)Solution:The three methods are cost leadership, differentiation, and response. Cost leadership can be illustrated by Wal-Mart, with low overhead and huge buying powerto pressure its suppliers into concessions. Differentiation can be illustrated by almost any restaurant or restaurant chain, such as Red Lobster, which offers a distinct menu and style of service than others. Response can be illustrated by a courier service such as FedEx, that guarantees specific delivery schedules; or by a custom tailor, who will hand make a suit specifically for the customer..2.5 Identify how change in the internal environmental affect the OM strategy for a company. For instance , discuss what impact the following internal factors might have on OM strategy:a) Maturing of a product.b) Technology innovation in the manufacturing process.c) Changes in product design that move disk drives from 3 1/2 inch floppy drive to CD-ROM drives.Solution: The 10 Operations Decisions are Product, Quality, Process, Location, Layout, Human resource, Supply chain, Inventory, Scheduling, Maintenance.Solution:(a) The maturing of a product may move the OM function to focus on more standardization, make fewer product changes, find optimum capacity, stabilize the manufacturing process, lower labor skills, use longer production runs, and institute cost cutting and design compromises.(b) Technological innovation in the manufacturing process may mean new human resources skills (either new personnel and/ or training of existing personnel), and added capital investment for new equipment or processes. Product design, layout, maintenance procedures, purchasing, inventory, quality standards, and procedures may all need to be revised.(c) A design change will, at least potentially, require the same changes as noted in (b).Chapter 3 Project ManagementDISCUSSION QUESTIONS11. Define early start, early finish, late finish, and late start times.SOLUTIONEarly start (ES) of an activity is the latest of the early finishtimes of all its predecessors.Early finish (EF) is the early start of an activity plus its duration.Late finish (LF) of an activity is the earliest of the late start times of all successor activities.Late start (LS) of an activity is its late finish less its duration.PROBLEMS3.7 Task time estimates for a production line setup project at Robert Klassen’sOntario factory are as follows.IMMEDIATEACTIVITY TIME (IN HOURS) PREDECESSORSA 6.0 ---B 7.2 ---C 5.0 AD 6.0 B,CE 4.5 B,CF 7.7 DG 4.0 E,Fa)Draw the project network using AON.b)Identify the critical path.c)What is the expected project length?d)Draw a Gantt chart for the project.SOLUTION(a)(b,c) There are four paths:Path Time (hours)A–C–E–G 19.5B–D–F–G 24.9A–C–D–F–G 28.7 (critical)B–E–G 15.73.17 Bill Fennema, president of Fennema Construction, has developed the task, durations, and predecessor relationships in the following table for building new motels. Draw the AON network and answer the question that follow.IMMEDIATE TIME ESTIMATES (IN WEEKS)ACTIVITY PREDECESSOR(S) OPTIMISTIC MOST LIKELY PESSIMISTICA --- 4 8 10B A 2 8 24C A 8 12 16D A 4 6 10E B 1 2 3F E,C 6 8 20G E,C 2 3 4H F 2 2 2I F 6 6 6J D,G,H 4 6 12 K I,J 2 2 3a)What is the expected time for activity C?b)What is the variance for activity C?c)Based on the calculation of estimated times, which is the critical path?d)What is the estimated time of the critical path?e)What is the activity variance along the critical path?f)What is the probability of completion of the project before week 36?SOLUTION(a) Estimated (expected) time for C = [8 + (4 × 12) + 16]/6= 72/6= 12 weeks(b) Variance for C is = 1.78(c) Critical path is A–C–F–H–J–K(d) Time on critical path = 7.67 + 12 + 9.67 + 2 + 6.67+ 2.17 = 40.18 weeks (rounded)(e) Variance on critical path = 1 + 1.78 + 5.44 + 0 + 1.78+ 0.03 = 10.03(f) Z== -1.32, which is about 9.6% chance (.096 probability) of completingproject before week 36.Note that based on possible rounding in part (d)—where time on critical path could be 40.3—the probability can be as low as 8.7%. So a student answerbetween 8.7% and 9.6% is valid.Summary table for problem 3.17 follows:Activity ActivityTimeEarlyStartEarlyFinishLateStartLateFinish SlackStandardDeviationA 7.66 0 7.66 0.0 7.66 0 1B 9.66 7.66 17.33 8 17.66 0.33 3.66C 12 7.66 19.66 7.66 19.66 0 1.33D 6.33 7.66 14 25 31.33 17.33 1E 2 17.33 19.33 17.66 19.66 0.33 0.33F 9.66 19.66 29.33 19.66 29.33 0 2.33G 3 19.66 22.66 28.33 31.33 8.66 0.33H 2 29.33 31.33 29.33 31.33 0 0I 6 29.33 35.33 32 38 2.66 0 J 6.66 31.33 38 31.33 38 0 1.33 K 2.16 38 40.17 38 40.17 0 0.17Chapter 4 Forecasting (p118)DISCUSSION QUESTIONS3. Identify the three forecasting time horizons. State an approximate duration for each.Solution:Short-range (under 3 months), medium-range (3 months to3 years), and long-range (over 3 years).4. Briefly describe the steps that are used to develop a forecasting system. Solution:The steps that should be used to develop a forecasting system are:(a) Determine the purpose and use of the forecast(b) Select the item or quantities that are to be forecasted(c) Determine the time horizon of the forecast(d) Select the type of forecasting model to be used(e) Gather the necessary data(f) Validate the forecasting model(g) Make the forecast(h) Implement and evaluate the results9. Briefly describe the Delphi technique. How would it be used by an employer you have worked for?Solution :The Delphi technique involves:(a) Assembling a group of experts in such a manner as to precludedirect communication between identifiable membersof the group(b) Assembling the responses of each expert to the questionsor problems of interest(c) Summarizing these responses(d) Providing each expert with the summary of all responses(e) Asking each expert to study the summary of the responsesand respond again to the questions or problems of interest.(f) Repeating steps (b) through (e) several times as necessaryto obtain convergence in responses. If convergence hasnot been obtained by the end of the fourth cycle, the responsesat that time should probably be accepted and theprocess terminated—little additional convergence islikely if the process is continued.PROBLEMS4.21 Refer to the trend-adjusted exponential smoothing illustration in Example ing α=. 2 andβ= .4 , we forecast sales for 9 mouths, showing the detailed calculations for mouth 2 and 3. In Solved Problem 4.2, we continued the process for mouth 4.In this problem, show your calculations for mouths 5 and 6 for Ft, Tt , and FITt.Solution:4.23 Sale of vegetable dehydrators at Bud Banis ’s discount department store in St. Louis over the past year are shown below. Management prepared a forecast using a combination of exponential smoothing and its collective judgment for the upcoming 4 mouths (March, April, May ,and June of 2005).Month 2004-2005 UnitSales Management’s ForecastJuly August September October November December January February MarchAprilMayJune 100939611012411992831019689108120114110108a)Compute MAD and MAPE for management’s technique.b)Do management’s results outperform (have smaller MADand MAPE than ) a naïve forecast?c)Which forecast do you recommend, based on lower forecasterror?Solution:Students must determine the naïve forecast for the fourmonths. The naïve forecast for March is the February actual of 83,etc.Chapter 5 Design of Goods and Services DISCUSSION QUESTIONS5. What is time-based competition?SOLUTIONTime-based competition uses a competitive strategy of gettingproducts to market rapidly and may include rapid design, efficient delivery systems, and JIT manufacturing.10. What information is contained in a bill of materials?SOLUTIONA bill of materials lists the components, their description,and the quantity of each required to make one unit of the product. 15.What are the advantages of computer-aided design?SOLUTIONSustainability in the context of OM implies a productionsystem that supports conservation and renewal of resources. Twoopportunities for a class discussion are:∉Pursue the OM role in product design, production, destruction/recycling/reuse and examine the entire productlife cycle (life cycle assessment [LCA] and ISO 14000).∉ Consider sustainability in a comprehensive and challengingperspective as meeting prese nt “needs” without compromisingthe ability of future generations to meet theirown “needs.” The concept of “need” and the suggestionthat we understand all there is to know about the world’sresources can initiate a lively classroom discussion.PROBLEMS5.11 The product design group of Flores Electric Supplies, Inc., has determinedthat it needs to design a new series if switches. It must decide on one of three design strategies. The market forecast is for 200,000 units. The better and more sophisticated the design strategy and the more time spent on value engineering, the less will be the variable cost. The chief of engineering design, Dr. W. L. Berry, has decided that the following costs are a good estimate of the initial and variable costs connected with each of the three strategies:a) Low-tech: a low-technology, low-cost process consisting if hiring seervalnew junior engineers. This option has a cost of $45,000 and variable-cost probabilities of .3 for $.55each, .4 for $.50, and .3 for $.45.b)Subcontract: a medium-cost approach using a good outside design staff.This approach would have an initial cost of $65,000 and variable-cost probabilities of .7 of $.45, .2 of $.40, and .1 of $.35.c)High-tech: a high-technology approach using the very best of the inside staffand the latest computer-aided design technology. This approach has a fixed cost of $75,000 and variable-cost probabilities of .9 of $.40 and .1 of $.35.What is the best decision based on an expected monetary value (EMV) criterion? (Note: We want the lowest EMV, as we are dealing with costs in this problem.)SOLUTIONThe firm should utilize the low technology approach for a cost of $145,000.Chapter 6 Forecasting (p174) DISCUSSION QUESTIONS1、E xplain how higher quality can lead to lower costs.Solution:Higher quality leads to greater demand, to greater market share, to greater economies of scale. Additionally, higher quality leads to less scrap, rework, and warranty cost, hence to less input required for same output.3、which 3 of Deming’s 14 points do you feel are most critical to the success of a TQM program. How are these related to Deming’s 14 points ? Solution:Of Deming’s 14 points, “finding problems” is certainly one of the three. The selection of the other two is not as clear-cut. Many would say “reducing fear” is important, but its purpose is really to find problems. The first point, on getting management to put forth common goals and stick with them—“constancy of purpose”—is our second choice. The third is “methods”—not giving goals without providing the methods to achieve them6、What are seven tools of TQM?Solution:The seven tools of TQM are:●Checksheet●Scatter diagram●Histograms●Pareto charts●Flow charts●Cause-and-effect diagrams●Statistical process control chart8、How can a university control the quality of its output (that is, its graduates)?Solution:● A university can seek to control the quality of its graduates by:Settingspecific goals for its overall accomplishments●Employing quality faculty●Setting appropriate standards (prerequisites, GPA, required credit hours, etc.)●Employing appropriate evaluation devices (quizzes, examinations, termpapers, etc.)Chapter 8DISCUSSION QUESTIONS4、What is “clustering”(集群)？Solution:4. Clustering is the tendency of firms to locate near competitors.16、List the techniques used by service organizations to select locations. Solution:16. Service location techniques: regression models to determine importance of various factors, factor rating method, traffic counts, demographic analysis of drawing area, purchasing power analysis of area, center-of-gravity method, and geographic information system. PROBLEMS8.9、A location analysis for Temponi Controls, a small manufacturer of part for high-technology cable systems, has been narrow down to four locations. Temponi will need to train assemblers, testers, and robotics maintainers in local training centers. Cecilia Temponi , the president, has asked each potential site to offer training programs, tax breaks, and other industrial incentives. The critical factors, their weights, and the ratings for each location are shown in the following table. High scores represent favorable values.Compute the composite (weighted average) rating for each location.a) Which site would you choose?b) Would you reach the same conclusion if the weights for operating cost and labor cost were reversed?Recompute as necessary and explain.SolutionFactorweight LocationAkron, OH Biloxi, MS Carthage, TX Denver, COLabor availability .15 90 80 90 80 Technical school quality .10 95 75 65 85 Operating cost .30 80 85 95 85 Land and construction cost .15 60 80 90 70 Industrial incentives .20 90 75 85 60 Labor cost.10758085758.15 A British hospital chain wishes to make its first entry into the U.S market by building a medical facility in the Midwest, a region with which its director. Doug Moodie, is comfortable because he got his medical degree at NorthwesternUniversity. After a preliminary analysis, four cities are chosen for further consideration. They are rated according to the factors shown below:Factor WeightCITYChicago Milwaukee Madison DetroitCost 2.0 8 5 6 7Need for afacility1.5 4 9 8 4Staff availability1.0 7 6 4 7Local incentives0.5 8 6 5 9a)Which city should Moodie select?b)Assume a minimum score of 5 is now required for all factors. Which cityshould be chosen?Solution:8.15 (a) Chicago = 16 + 6 + 7 + 4 = 33Milwaukee = 10 + 13.5 + 6 + 3 = 32.5Madison = 12 + 12 + 4 + 2.5 = 30.5Detroit = 14 + 6 + 7 + 4.5 = 31.5All four are quite close, with Chicago and Milwaukeealmost tied. Chicago has the largest rating, with a 33.(b) With a cutoff of 5, Chicago is unacceptable because it scoresonly 4 on the second factor. Only Milwaukee has scores of 5or higher on all factors. Detroit and Madison are also eliminated,as each has one rating of a 4.8.21 A chain of home health care firms in Louisiananeeds to locate a central office from which to conduct internal audits and other periodic reviews of its facilities. These facilities are scattered throughout the state, as detailed in the following table. Each site, except for Houma, will be visited three times each year by a team of workers, who willdrive from the central office to the site. Houma will be visited five times a year. Which coordinates represent a good central location for this office? What other factors might influence the office location decision? Where would you place this office? Explain.CityMap CoordinatesX YCovington 9.2 3.5Donaldsonville 7.3 2.5Houma 7.8 1.4Monroe 5.0 8.4Natchitoches 2.8 6.5New Iberia 5.5 2.4Opelousas 5.0 3.6Ruston 3.8 8.5 Solution:Chapter 9 Layout Strategy DISCUSSION QUESTIONS2. What are the three factors that complicate a fixed-position layout? SOLUTION：Fixed position layouts are complicated by: limited spaceat virtually all sites; at different stages of the process, differentmaterials are needed; and the volume of materials needed is dynamic.3. What are the advantages and disadvantages of process layout? SOLUTION：The advantages of a process layout are:It can simultaneously handle a wide variety of products or services, especially in terms of “batches” or “job lots.”It has considerable flexibility with respect to equipment and labor assignments.The disadvantages of a process layout are:The use of general purpose rather than special purpose equipment tends to make the overall process somewhat lessefficient.Orders take more time and money to move through the system because of the difficult scheduling, setting up the processfor a wide variety of orders, and considerable materialhandling.Labor skill requirements tend to be high because of the use of general purpose equipment.Work-in-process inventories tend to be high.8. What are the advantages and disadvantages of work cells? SOLUTION：The advantages of work cells are:Reduction in work-in-process inventoryReduction in required floor spaceReduced raw material and finished goods inventoryReduced direct labor costHeightened sense of employee participationIncreased utilization of equipment and machineryReduced investment in machinery and equipmentThe disadvantages are:Similar to a product layoutHigh volume is required because of the large investment needed to set up the processThere is a lack of flexibility in handling a variety of productsor production ratesRequires the use of group technologyRequires a high level of training and flexibility on the partof employeesEither considerable staff support or imaginative employeesare needed for the initial development of the work cells11. What layout variables would you consider particularly important in an officelayout where computer programs are written?SOLUTION：Some of the layout variables you might want to consider asparticularly important in an office where computer programs are tobe written are:Ease of communicationProvision of privacy and a quiet work environmentLighting—especially as it related to glare on computer screensConsideration of ergonomic or human factor issues inequipment layout and construction14. Visit a local supermarket and sketch its layout. What are your observationsregarding departments and their locations?SOLUTION：Each student will sketch the layout of a local supermarket.They should observe the long aisles, power items at aisle caps, andspread of staples at corners of store (fruit/meat/dairy/bakery).PROBLEMS9.1 Registration at Southern University has always been a time of emotion,commotion, and lines. Students must move among four stations to complete the trying semiannual process. Last semester’s registration, held in the fieldhouse, is described in Figure 9.19. You can see, for example, that 450 students moved from the paperwork station (A) to advising (B), and 550 went directly from A to picking up their class cards (C). Graduate students, who for the most part had preregistered, proceeded directly from A to station where registration is verified and payment collected (D). The layout used last semester is also shown in Figure 9.19. The registrar is preparing to set up this semester’s stations and is anticipating similar numbers.a) What is the “load * distance,” or “movement cost,” of the layout shown?b) Provide an improves layout and compute its movement cost.SOLUTION：Movements = (4×8) + (9× 7) + (7× 4) + (6×3) + (8× 2) + (10×6)= 32 + 63 + 28 +18 +16 + 60 = 217 (in 100s)= 21,700Cost = 21,700 × $1 = $21,7009.5 Reid Chocolates (see Problem 9.4) is considering a third layout, as shownbelow. Evaluate its effectiveness in Trip-distance feet.SOLUTION：(b) Improved layout:B AC D9.7 The Temple Toy Company has decided to manufacture a new toy tractor, the production of which is broken into six steps. The demand for the tractor is 4,800 units per 40-hour workweek:PERFORMANCE TIMETask (SECONDS) PREDECESSORSA 20 NoneB 30 AC 15 AD 15 AE 10 B,CF 30 D,Ea)Draw a precedence diagram of this operation.b)Given the demand, what is the cycle time for this operation?c)What is the theoretical minimum number of workstations?d)Assign tasks to workstations.e)How much total idle time is present each cycle?f)What is the overall efficiency of the assembly line with 4stations; with 5 stations; and with 6 stations?SOLUTION:。
