Chapter_27(ProjectScheduling)(中英版).ppt

1、1,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Chapter 27,Project Scheduling,Slide Set to accompanySoftware Engineering: A Practitioners Approach, 7/e by Roger S. Pressman Slides copyright 1996,

2、 2001, 2005, 2009 by Roger S. Pressman For non-profit educational use only May be reproduced ONLY for student use at the university level when used in conjunction with Software Engineering: A Practitioners Approach, 7/e. Any other reproduction or use is prohibited without the express written permiss

3、ion of the author. All copyright information MUST appear if these slides are posted on a website for student use,第二十七章,进度管理,2,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,3,These slides are desi

4、gned to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Why Are Projects Late,an unrealistic deadline established by someone outside the software development group changing customer requirements that are not reflected in sched

5、ule changes; an honest underestimate of the amount of effort and/or the number of resources that will be required to do the job; predictable and/or unpredictable risks that were not considered when the project commenced; technical difficulties that could not have been foreseen in advance; human diff

6、iculties that could not have been foreseen in advance; miscommunication among project staff that results in delays; a failure by project management to recognize that the project is falling behind schedule and a lack of action to correct the problem,项目为何会延期,制定了一个完全不能实现的交付期限 用户的需求变更没能及时反映在进度计划中 未能正确估计

7、每项任务所需工作量 项目开始前未能仔细分析项目的风险 技术难题及人员问题未能提前预估 项目工作人员之间的沟通不畅而造成的延误 项目管理者不承认项目滞后不采取行动纠正问题,4,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,5,These slides are designed to accompany Software Engineering:

8、 A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Scheduling Principles,compartmentalizationdefine distinct tasks interdependencyindicate task interrelationship effort validationbe sure resources are available defined responsibilitiespeople must be assigned d

9、efined outcomeseach task must have an output defined milestonesreview for quality,项目计划设置原则,任务分解定义不同的任务 任务关联指出任务之间的相互关系 资源确认确认资源的可用性 明确责任详细规定关键人员的职责 定义输出每一个任务必须有一个成果 制定里程碑用于质量审查,6,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides cop

10、yright 2009 by Roger Pressman,7,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Effort and Delivery Time,投入和交付时间,8,These slides are designed to accompany Software Engineering: A Practitioners Appro

11、ach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,9,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Effort Allocation,front end” activities customer communication analysis design

12、 review and modification construction activities coding or code generation testing and installation unit, integration white-box, black box regression,投入的分配,10,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger

13、 Pressman,前端”活动 客户沟通 分析 设计 审查和修改 建筑活动 编码或代码生成 测试和安装 单元，整合 白盒，黑盒 回归,11,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Defining Task Sets,determine type of project assess the degree of rigor require

14、d identify adaptation criteria select appropriate software engineering tasks,定义任务集,确定项目类型 评估需求的精确程度 确定符合需求的条件 选择适当的工程任务,12,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,13,These slides are design

15、ed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Task Set Refinement,1.1 Concept scoping determines the overall scope of the project,Task definition: Task 1.1 Concept Scoping 1.1.1Identify need, benefits and potential cus

16、tomers; 1.1.2Define desired output/control and input events that drive the application; Begin Task 1.1.2 1.1.2.1FTR: Review written description of need FTR indicates that a formal technical review (Chapter 26) is to be conducted. 1.1.2.2Derive a list of customer visible outputs/inputs 1.1.2.3FTR: Re

17、view outputs/inputs with customer and revise as required; endtask Task 1.1.2 1.1.3Define the functionality/behavior for each major function; Begin Task 1.1.3 1.1.3.1FTR: Review output and input data objects derived in task 1.1.2; 1.1.3.2Derive a model of functions/behaviors; 1.1.3.3FTR: Review funct

18、ions/behaviors with customer and revise as required; endtask Task 1.1.3 1.1.4Isolate those elements of the technology to be implemented in software; 1.1.5Research availability of existing software; 1.1.6Define technical feasibility; 1.1.7Make quick estimate of size; 1.1.8Create a Scope Definition; e

19、ndTask definition: Task 1.1,is refined to,任务设置细化,1.1概念范围界定 确定项目的整体范围。 任务定义：任务1.1概念范围界定 1.1.1识别需求、收益和潜在客户; 1.1.2定义期望的输出/控制和输入事件驱动程序; 1.1.2任务开始 1.1.2.1FTR：检查书面的需求描述 （FTR：正式技术复审Formal Technical Review ） 1.1.2.2获得客户明显的输入输出清单 1.1.2.3与客户一同审核输入输出，并按照客户要求修改 1.1.2 任务结束 1.1.3为每个主要的功能定义功能描述及性能要求 1.1.3任务开始 1.1.

20、3.1 FTR:检查从1.1.2中导出的输入输出数据项 1.1.3.2导出相应的功能/性能模型 1.1.3.3 FTR：与客户一同审核功能/性能模型，并按照客户要求修改 1.1.3任务结束 1.1.4隔离那些软件实现的技术元素 1.1.5研究现有软件的可用性 1.1.6定义技术可行性 1.1.7快速的对软件规模作出估计 1.1.8创建一个范围 任务1.1定义结束,14,15,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009).

21、Slides copyright 2009 by Roger Pressman,Define a Task Network,定义任务网络,16,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,17,These slides are designed to accompany Software Engineering: A Practitione

22、rs Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Timeline Charts,时间轴图,18,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,19,These slides are designed to accompany Softwa

23、re Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Use Automated Tools toDerive a Timeline Chart,使用自动化的工具，得出一个时间轴图,20,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright

24、 2009 by Roger Pressman,21,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Schedule Tracking,conduct periodic project status meetings in which each team member reports progress and problems. evalua

25、te the results of all reviews conducted throughout the software engineering process. determine whether formal project milestones (the diamonds shown in Figure 27.3) have been accomplished by the scheduled date. compare actual start-date to planned start-date for each project task listed in the resou

26、rce table (Figure 27.4). meet informally with practitioners to obtain their subjective assessment of progress to date and problems on the horizon. use earned value analysis (Section 27.6) to assess progress quantitatively,进度跟踪,定期进行项目状态跟踪会议，由每个团队成员报告的进展和问题 。 评估整个软件工程过程的所有审查的结果 。 确定正式的项目里程碑是否在预定日期已完成。

27、 比较资源表中列出的每一项任务的实际的启动日期和计划开始日期。 通过跟项目人员的非正式交流获得他们目前的进展和存在的问题。 使用挣值分析（第27.6）定量评估进展,22,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,23,These slides are designed to accompany Software Engineering:

28、A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Progress on an OO Project-I,Technical milestone: OO analysis completed All classes and the class hierarchy have been defined and reviewed. Class attributes and operations associated with a class have been defin

29、ed and reviewed. Class relationships (Chapter 8) have been established and reviewed. A behavioral model (Chapter 8) has been created and reviewed. Reusable classes have been noted. Technical milestone: OO design completed The set of subsystems (Chapter 9) has been defined and reviewed. Classes are a

30、llocated to subsystems and reviewed. Task allocation has been established and reviewed. Responsibilities and collaborations (Chapter 9) have been identified. Attributes and operations have been designed and reviewed. The communication model has been created and reviewed,面向对象的项目进展-1,技术里程碑：面向对象分析完成 所有

31、的类和类层次结构已确定并通过审查 。 类属性和一类相关的操作已确定并通过审查 。 类之间关系（第8章）已经建立并通过审查 。 一个行为模型（第8章）已创建并通过审查 。 可重用类已标注 。 技术里程碑：面向对象设计完成 子系统集（第9章）被定义并通过审查. 类分配给子系统并通过审查 . 任务分配已经成立，并通过审查 . 责任和协作（第9章）已被确定. 属性和操作已经设计并通过审查 . 沟通的模式已经建立并通过审查,24,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7

32、/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,25,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Progress on an OO Project-II,Technical milestone: OO programming completed Each new

33、 class has been implemented in code from the design model. Extracted classes (from a reuse library) have been implemented. Prototype or increment has been built. Technical milestone: OO testing The correctness and completeness of OO analysis and design models has been reviewed. A class-responsibilit

34、y-collaboration network (Chapter 6) has been developed and reviewed. Test cases are designed and class-level tests (Chapter 19) have been conducted for each class. Test cases are designed and cluster testing (Chapter 19) is completed and the classes are integrated. System level tests have been compl

35、eted,面向对象的项目进展-2,技术里程碑：面向对象编程完成 每一个新的类已按照设计模型完成编码。 提取类（从重用库）已完成。 原型或增量已经建立。 技术里程碑：面向对象的测试 面向对象分析和设计的正确性和完整性通过审查。 负责协作的网络（第6章）已制定并通过审查。 测试用例设计完成，并对每个类进行测试（第19章）。 测试用例设计完成，集成测试已经完成（第19章）。 系统级的测试已经完成,26,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-H

36、ill 2009). Slides copyright 2009 by Roger Pressman,27,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Earned Value Analysis (EVA,Earned value is a measure of progress enables us to assess the “perc

37、ent of completeness” of a project using quantitative analysis rather than rely on a gut feeling “provides accurate and reliable readings of performance from as early as 15 percent into the project.” Fle98,挣值分析（EVA,挣值 是一种对进度的衡量 使我们能够使用定量分析方法来评估项目的完成百分比，而不是依靠直觉 提供提前于项目15%的准确定和可靠性 FLE98,28,These slides

38、 are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,29,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Computi

39、ng Earned Value-I,The budgeted cost of work scheduled (BCWS) is determined for each work task represented in the schedule. BCWSi is the effort planned for work task i. To determine progress at a given point along the project schedule, the value of BCWS is the sum of the BCWSi values for all work tas

40、ks that should have been completed by that point in time on the project schedule. The BCWS values for all work tasks are summed to derive the budget at completion, BAC. Hence, BAC = (BCWSk) for all tasks k,挣值计算 -1,计划工作量的预算成本被确定为每一项工作任务在项目中的反应。. BCWS反映进度计划应当完成的工作量。 要确定项目进度计划中某一点的进度，BCWS是所有这一点应该完成的工作量

41、的费用总和。 BCWS的值是由所有完成的工作的预算相加得出的 ,因此： BAC = (BCWSk) for all tasks k,30,These slides are designed to accompany Software Engineering: A Practitioners Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,31,These slides are designed to accompany Software Engineering: A Practitioners

42、Approach, 7/e (McGraw-Hill 2009). Slides copyright 2009 by Roger Pressman,Computing Earned Value-II,Next, the value for budgeted cost of work performed (BCWP) is computed. The value for BCWP is the sum of the BCWS values for all work tasks that have actually been completed by a point in time on the

43、project schedule. “the distinction between the BCWS and the BCWP is that the former represents the budget of the activities that were planned to be completed and the latter represents the budget of the activities that actually were completed.” Wil99 Given values for BCWS, BAC, and BCWP, important progress indicators can be computed: Schedule performance index, SPI = BCWP/BCWS Schedule variance, SV = BCWP BCWS SPI is an indication of the efficiency with which the project is utilizing scheduled r