软件工程课件：02-Software Project Management

1、Outline1Why and What?The PeopleWork BreakdownSchedulingSummarySoftware Project ManagementConcerned with activities involved in ensuring that software is delivered On budgetOn schedule QualityIn accordance with the requirements of the organisations developing and procuring the software2A project is l

2、ike a road trip. Some projects are simple and routine, like driving to the store in broad daylight. But most projects worth doing are more like driving a truck off-road, in the mountains, at night. C. Kaner, J. Bach, and B. PettrichordW5HH Plan Why is the system being developed?What will by done, by

3、 when?Who is responsible for a function?Where are they organizationally located?How will the job be done technically and managerially?How much of each resource is needed?-Boehm3Software Project ManagementUmbrella activitiesMeasurement & metricsEstimationRisk ScheduleTracking & controlPeople is the p

4、ivot element4The PeoplePM-CMM :“to enhance the readiness of software organizations to undertake increasingly complex applications by helping attract, grow, motivate, deploy, and retain the talent needed to improve their software development capability” B. Curtis 1994Key practicesRecruit, selection,

5、performance management, training, compensation, career development, organization and work design and team/culture development5The StakeholdersSenior managersProject (technical) managersPractitionersCustomers End users6The Win-Win StrategySoftware Team“Not every group is a team, and not every team is

6、 effective”To achieve a high-performance teamTeam members must have trust in one another.The distribution of skills must be appropriate to the problem.Mavericks may have to be excluded from the team, if team cohesiveness is to be maintained. 7“We success and fail as a team”荣辱与共风雨同舟Team LeaderKey tra

7、its Edgemon 95Problem solvingDiagnose the technical and organizational issues that are most relevantSystematically structure a solutionLearn lessons from past experiencesFlexibly adjust solutionsManagerial identityControl over the projectAchievementReward initiative and accomplishmentInfluence and t

8、eam building“read” people, and react to the needs of team members8Team LeaderMaximize each persons skills and abilitiesKey traits Weinberg 86MotivationEncourage technical people to produce to their best abilityOrganizationEnable the initial concept to be translated in to a final productIdeas or inno

9、vationEncourage people to create and feel creative9IncentiveResponsibilityCommunication & CoordinationThe scale of many development efforts is large, leading to complexity, confusion, and significant difficulties in coordinating team members. To establish effective coordination methods is critical t

10、o deal with the problemFormal, impersonal approachesFormal, interpersonal proceduresInformal, interpersonal proceduresElectronic communicationInterpersonal network10If you want to be incrementally better: Be competitive.If you want to be exponentially better: Be cooperative. Outline11Why and What?Th

11、e PeopleWork BreakdownSchedulingSummaryWork Breakdown StructureBreakdown tasks into manageable elementsProduct ProcessOrganizationTop-down refinementAnalyze and organize the overall scopeEnsure nothing leftEvaluate and assess the realism1213An Example of Work Breakdown Structure14Responsibility Assi

12、gnment MatrixResponsibility Assignment Matrix15An example of Responsibility Assignment MatrixSchedulingQuestion: “How does a project get to be a year late?”Answer: “One day at a time.”16Scheduling17TasksResourcesTimelineSchedulingDefine all project tasksIdentify critical path and the milestonesIdent

13、ify the deliverables Tack the process to ensure that delay is recognized and controlled18Tasks On large projects, hundreds of small tasks must occur to accomplish a larger goalSome of these tasks lie outside the mainstream and may be completed without worry of impacting on the project completion dat

14、eOther tasks lie on the critical path; if these tasks fall behind schedule, the completion date of the entire project is put into jeopardy19(More on next slide)Purpose of a Task NetworkAlso called an activity networkIt is a graphic representation of the task flow for a projectIt depicts task length,

15、 sequence, concurrency, and dependencyPoints out inter-task dependencies to help the manager ensure continuous progress toward project completionThe critical path A single path leading from start to finish in a task networkIt contains the sequence of tasks that must be completed on schedule if the p

16、roject as a whole is to be completed on scheduleIt also determines the minimum duration of the project20Example Task Network21Task A3Task B3Task E8Task F2Task H5Task C7Task D5Task I4Task M0Task N2Task G3Task J5Task K3Task L10Where is the critical path and what tasks are on it?Critical Path MethodPur

17、poseProvides a graphical view of the project.Predicates the time required to complete the project.Shows which activities are critical to maintaining the schedule and which are not. Determine whether or not the project is on scheduleCPM project planning stepsSpecify the individual activitiesDetermine

18、 the sequence of those activitiesDraw a network diagramEstimate the completion time for each activityIdentify the critical pathUpdate the CPM diagram as the project progresses22Critical Path CalculationCritical path is the longest-duration path through the network.The activities lie on it cannot be

19、delayed without delaying the project.To accelerate the project, it is necessary to reduce the total time required for the activities in the critical path. The parametersEST earliest start timeThe earliest time at which the activity can start given that its precedent activities must be completed firs

20、t.EFT earliest finish timeEST + the activity duration timeLFT latest finish timeThe latest time at which the activity can be completed without delaying the projectLST latest start timeLFT the activity duration time23Critical Path MethodSlack time = LST EST = Available time - real timeCritical PathTh

21、e longest pathFor each node in the path, slack time = 0, that is, LST=EST, and EFT=LFT24Critical Path Method25260414180363670292962302854128402020301414206610000STLSTESTNodeEST: Earliest Start TimeLST: Latest Start TimeST: Slack TimeExample Task Networkwith Critical Path Marked27Critical path: A-B-C

22、-E-K-L-M-NTask A3Task B3Task E8Task F2Task H5Task C7Task D5Task I4Task M0Task N2Task G3Task J5Task K3Task L10Mechanics of a Timeline ChartAlso called a Gantt chart; invented by Henry Gantt, industrial engineer, 1917All project tasks are listed in the far left columnThe next few columns may list the

23、following for each task: projected start date, projected stop date, projected duration, actual start date, actual stop date, actual duration, task inter-dependencies (i.e., predecessors)To the far right are columns representing dates on a calendarThe length of a horizontal bar on the calendar indica

24、tes the duration of the taskWhen multiple bars occur at the same time interval on the calendar, this implies task concurrencyA diamond in the calendar area of a specific task indicates that the task is a milestone; a milestone has a time duration of zero2829J 2Install Inc TwoKE5Install Inc OneFE, I6

25、Test Inc TwoJA, B7Analyze Inc TwoGF, KHGDCBANonePred.2Close out projectL4Code Inc TwoI5Design Inc TwoH10Test Inc OneE7Code Inc OneD8Design Inc OneC3Analyze Inc OneB4/13Establish incrementsAFinishStartDurationTask NameTask #4/1 4/8 4/15 4/22 4/29 5/6 5/13 5/20 5/27 6/3Task network and the critical pa

26、th:Timeline chart:CLASS EXERCISE30J 5/95/82Install Inc TwoKE5/65/25Install Inc OneFE, I5/75/26Test Inc TwoJA, B4/134/77Analyze Inc TwoGF, KHGDCBANonePred.5/115/102Close out projectL4/224/194Code Inc TwoI4/184/145Design Inc TwoH5/14/2210Test Inc OneE4/214/157Code Inc OneD4/144/78Design Inc OneC4/64/4

27、3Analyze Inc OneB4/34/13Establish incrementsAFinishStartDurationTask NameTask #A. EstablishIncrements3B. AnalyzeInc One3C. DesignInc One8D. CodeInc One7F. InstallInc One5G. AnalyzeInc Two7H. DesignInc Two5I. CodeInc Two4K. InstallInc Two2L. Close outProject2E. TestInc One10J. TestInc Two64/1 4/8 4/1

28、5 4/22 4/29 5/6 5/13 5/20 5/27 6/3Task network and the critical path:Timeline chart:SOLUTIONA-B-C-D-E-J-K-LExample Timeline Chart31ChallengesFactors that Influence a Projects ScheduleSize of the projectNumber of potential usersMission criticalityApplication longevityStability of requirementsEase of

29、customer/developer communicationMaturity of applicable technologyPerformance constraintsEmbedded and non-embedded characteristicsProject staffReengineering factors33Scheduling ProblemsEstimating the difficulty of problems and hence the cost of developing a solution is hardProductivity is not proport

30、ional to the number of people working on a taskAdding people to a late project makes it later because of communication overheadsThe unexpected always happens. Always allow contingency in planning3440-20-40 Distribution of EffortA recommended distribution of effort across the software process is 40% (analysis and design), 20% (coding), and 40% (testing)Work expended on project planning rarely accounts for more than 2 - 3% of the total effortRequirements analysis may c