暨南大学项目管理chapter5estimatingprojecttimesandcosts

1、 管理学院 school of management 佟瑞 edward tong， mpm，mba2021-10-211edward tongcopyright reserved jinan university 52where we are now53estimating projects estimating the process of forecasting or approximating the time and cost of completing project deliverables. the task of balancing expectations of stake

2、holders and need for control while the project is implemented. types of estimates top-down (macro) estimates: analogy, group consensus, or mathematical relationships bottom-up (micro) estimates: estimates of elements of the work breakdown structure54why estimating time and cost are importantexhibit

3、5.1 to support good decisions. to schedule work. to determine how long the project should take and its cost. to determine whether the project is worth doing. to develop cash flow needs. to determine how well the project is progressing. to develop time-phased budgets and establish the project baselin

4、e.55factors influencing the quality of estimatesquality of estimatesprojectdurationpeopleproject structure and organizationpaddingestimatesorganizationcultureother (nonproject)factorsplanning horizon56estimating guidelines for times, costs, and resources1. have people familiar with the tasks make th

5、e estimate.2. use several people to make estimates.3. base estimates on normal conditions, efficient methods, and a normal level of resources.4. use consistent time units in estimating task times.5. treat each task as independent, dont aggregate.6. dont make allowances for contingencies.7. adding a

6、risk assessment helps avoid surprises to stakeholders.57top-down versus bottom-up estimating top-down estimates are usually are derived from someone who uses experience and/or information to determine the project duration and total cost. are made by top managers who have little knowledge of the proc

7、esses used to complete the project. bottom-up approach can serve as a check on cost elements in the wbs by rolling up the work packages and associated cost accounts to major deliverables at the work package level.58top-down versus bottom-up estimatingtable 5.1conditions for preferring top-down or bo

8、ttom-up time and cost estimatescondition macro estimates micro estimatesstrategic decision making x cost and time important xhigh uncertainty xinternal, small project xfixed-price contract xcustomer wants details xunstable scope x59estimating projects: preferred approach make rough top-down estimate

9、s. develop the wbs/obs. make bottom-up estimates. develop schedules and budgets. reconcile differences between top-down and bottom-up estimates510top-down approaches for estimating project times and costs consensus methods ratio methods apportion method function point methods for software and system

10、 projects learning curvesproject estimatetimescosts511apportion method of allocating project costs using the work breakdown structurefigure 5.1512simplified basic function point count process for a prospective project or deliverabletable 5.2513example: function point count methodtable 5.3514bottom-u

11、p approaches for estimating project times and costs template methods parametric procedures applied to specific tasks range estimates for the wbs work packages phase estimating: a hybrid515support cost estimate worksheetfigure 5.2516phase estimating over product life cyclefigure 5.3517top-down and bo

12、ttom-up estimatesfigure 5.4518level of detail level of detail is different for different levels of management. level of detail in the wbs varies with the complexity of the project. excessive detail is costly. fosters a focus on departmental outcomes creates unproductive paperwork insufficient detail

13、 is costly. lack of focus on goals wasted effort on nonessential activities519types of costs direct costs costs that are clearly chargeable to a specific work package. labor, materials, equipment, and other direct (project) overhead costs costs incurred that are directly tied to an identifiable proj

14、ect deliverable or work package. salary, rents, supplies, specialized machinery general and administrative overhead costs organization costs indirectly linked to a specific package that are apportioned to the project520contract bid summary costsfigure 5.5 direct costs direct overhead total direct co

15、sts g&a overhead (20%) total costs profit (20%) total bid $80,000 $20,000 $100,000 $20,000 $120,000 $24,000 $144,000 521three views of costfigure 5.6522refining estimates reasons for adjusting estimates interaction costs are hidden in estimates. normal conditions do not apply. things go wrong on pro

16、jects. changes in project scope and plans. adjusting estimates time and cost estimates of specific activities are adjusted as the risks, resources, and situation particulars become more clearly defined.523creating a database for estimatingfigure 5.7524key termsapportionment methodsbottom-up estimate

17、scontingency fundsdelphi methoddirect costsfunction pointslearning curvesoverhead costspadding estimatesphase estimatingrange estimatingratio methodstemplate methodtime and cost databases525wbs figuretable 5.4526learning curves unit valuestable a5.1527learning curves cumulative valuestable a5.22021-

18、10-21edward tong2008 copy reserved jinan university281the process of forecasting or approximating the time and cost of completing project deliverables is called c a. budgetingb. predictingc. estimatingd. planninge. guesstimating2021-10-21edward tong2008 copy reserved jinan university292in practice,

19、estimating processes are frequently classified as aa. top down/bottom upb. rough/polishedc. precise/order of magnituded. draft/finale. both a and b are correct2021-10-21edward tong2008 copy reserved jinan university303a typical statement in actual practice is that estimates should have a probability

20、 of being met _ of the time. ca. 100%b. 98%c. 95%d. 90%e. 80%2021-10-21edward tong2008 copy reserved jinan university314a good starting point for developing time and cost estimates is aa. past experienceb. work packagesc. task analysisd. time and motion studiese. work breakdown structure52021-10-21e

21、dward tong2008 copy reserved jinan university32 which of the following is not one of the factors that need to be considered to improve quality of estimates for project times and costs? da. planning horizonb. peoplec. padding estimatesd. profite. project structure62021-10-21edward tong2008 copy reser

22、ved jinan university33ed is looking over the actual results of projects and comparing them to what was estimated. he notices that projects that took six months or longer to complete were noticeably more off the estimates. which of the following factors is he recognizing? ba. padding estimatesb. plan

23、ning horizonc. project structured. peoplee. organization culture72021-10-21edward tong2008 copy reserved jinan university34janet is forecasting how much money her department needs to support a new project. she estimates that two people and $25,000 in expenses will cover her needs. because management

24、 typically insists on reducing forecasts by 20 percent, she increases her estimates to allow for that reduction. which of the following factors is illustrated in this situation? a a. padding estimatesb. planning horizonc. project structured. peoplee. organization culture82021-10-21edward tong2008 co

25、py reserved jinan university35 which of the following is a good condition for top-down estimating? da. cost and time importantb. fixed price contractc. customer wants detailsd. internal, small projecte. all of these are good conditions for top-down estimating92021-10-21edward tong2008 copy reserved

26、jinan university36which of the following is a good condition for bottom-up estimating? ca. strategic decision makingb. internal, small projectc. fixed price contractd. high uncertaintye. both c and d are good conditions for bottom-up estimating102021-10-21edward tong2008 copy reserved jinan universi

27、ty37top-down estimates are most likely to occur during the _ phase. aa. conceptb. planningc. executiond. deliverye. all of these are equally likely112021-10-21edward tong2008 copy reserved jinan university38_ estimates are most likely to use low cost, efficient methods. da. apportionb. ratioc. top-d

28、ownd. bottom-upe. all of these are equally likely122021-10-21edward tong2008 copy reserved jinan university39 which of the following methods is not considered a top-down approach to estimating project time and cost? ba. ratiob. templatec. apportiond. function pointe. learning curve132021-10-21edward

29、 tong2008 copy reserved jinan university40jose is forecasting project time and cost for constructing a new building by multiplying the total square footage by a given dollar amount. which of the following methods is he using? aa. ratiob. templatec. apportiond. function pointe. learning curve142021-1

30、0-21edward tong2008 copy reserved jinan university41sean is forecasting the time and cost of developing a customized software program by looking at the number of inputs, outputs, inquires, files, and interfaces. which of the following methods is he using? da. ratiob. templatec. apportiond. function

31、pointe. learning curve152021-10-21edward tong2008 copy reserved jinan university42laura is forecasting the time and cost of developing an intranet for a new customer. her department has completed six such intranets for customers during the last two years. although the proposed system is about the sa

32、me size as the others she estimates that it will take about 10 percent less time and money. which of the following methods is she using? ea. ratiob. templatec. apportiond. function pointe. learning curve162021-10-21edward tong2008 copy reserved jinan university43 learning curves are more likely to a

33、pply in situations where most of the costs are ba. materialsb. laborc. overheadd. evenly spread over materials, labor, and overheade. all of these are equally likely situations for learning curves172021-10-21edward tong2008 copy reserved jinan university44which of the following is not one of the bot

34、tom-up approaches to estimating project time and cost? a. parametric procedures applied to specific tasksb. estimates for the wbs work packages cc. learning curved. template methode. all of these are bottom-up approaches182021-10-21edward tong2008 copy reserved jinan university45the approach that be

35、gins with a top-down estimate for the project and then refines estimates as the project is implemented is known as _ method. da. function pointb. templatec. learning curved. phase estimatinge. apportion192021-10-21edward tong2008 copy reserved jinan university46which of the following would be the be

36、st method for projects where the final product is not known and the uncertainty is very large? da. function pointb. templatec. learning curved. phase estimatinge. apportion202021-10-21edward tong2008 copy reserved jinan university47the accuracy of top-down estimates will typically be in the range of

37、 ca. minus 50% to plus 50%b. minus 0% to plus 75%c. minus 20% to plus 60%d. minus 35% to plus 35%e. minus 10% to plus 30%212021-10-21edward tong2008 copy reserved jinan university48 the accuracy of bottom-up estimates will typically be in the range of ea. minus 50% to plus 50%b. minus 0% to plus 75%

38、c. minus 20% to plus 60%d. minus 35% to plus 35%e. minus 10% to plus 30%222021-10-21edward tong2008 copy reserved jinan university49 the cost to prepare bottom-up estimates will typically run how much more than the costs to prepare the top-down estimates? ca. about the sameb. about twice as muchc. a

39、bout three times as muchd. about four times as muche. about five times as much232021-10-21edward tong2008 copy reserved jinan university50typical kinds of costs found in a project include ea. direct costsb. project overhead costsc. general and administrative costsd. only a and b are includede. a, b,

40、 and c are all included242021-10-21edward tong2008 copy reserved jinan university51project costs are typically viewed from all of the following except: ba. scheduledb. sunkc. actuald. committede. all of these are correct252021-10-21edward tong2008 copy reserved jinan university52 which of the follow

41、ing would be considered a direct project cost? ea. laborb. materialsc. equipmentd. both a and b are direct costse. a, b, and c are all considered direct costs262021-10-21edward tong2008 copy reserved jinan university53which of the following is not one of the recommended guidelines for developing use

42、ful work package estimates? a. estimates should be made by those responsible for the work db. use several people to estimate the same workc. estimates should be based on normal conditionsd. estimates should include a normal level of contingencye. estimates should be independent of other projects2720

43、21-10-21edward tong2008 copy reserved jinan university54companies like boeing, kodak, and ibm are using which of the following for improving the estimating process? da. adjusting estimates based on individual forecasting abilitiesb. benchmarking using the experience of other companiesc. using time a

44、nd motion studiesd. creating historical databases of previous projectse. all of these are correct282021-10-21edward tong2008 copy reserved jinan university55reasons why estimating time and cost are important include all of the following except: ea. to schedule workb. to determine how long the projec

45、t should take and costc. to develop cash flow needsd. to determine how well the project is progressinge. all of the above are valid reasons292021-10-21edward tong2008 copy reserved jinan university56in a learning curve, the improvement ratio is applied to which of the following items? ba. direct mat

46、erialsb. direct laborc. overheadd. both a and b are correcte. a, b, and c are all correct302021-10-21edward tong2008 copy reserved jinan university57the bottom-up approach for estimating times and costs that uses costs from past projects that were similar to the current project is known as: ba. detailed wbs work package estimatesb. template methodc. function point methodd. time-phased cost estimatese. phase estimating312021-10-21edward tong2008 copy reserved jinan university58which of the follow top-down methods is u