ch07

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更新项目进度
Updating the Project Schedule
An updated project schedule can be calculated based on actual finish times of completed activities 基于已经完成的活动的实际完成时间计算新的 项目进度
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Project Control Process
The key to effective project control is to measure actual progress and compare it to planned progress on a timely and regular basis and to take necessary corrective action immediately. Establish a regular reporting period. During each reporting period, collect: – data on actual performance – information on any changes to project scope, schedule and budget. If changes are incorporated, a new plan must be established. 5
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Schedule Control for Information Systems Development
Common necessary changes during IS development projects: Changes to input screens Changes to reports Changes to on-line queries Changes to database structures Changes to software processing routines Changes to processing speeds
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Approaches to Schedule Control
Four Steps
– Analyze the schedule分析进度 – Decide what corrective actions should be taken, if any确定应采取哪种具体的纠正措施 – Revise the plan修改计划(将纠正措施列入计 划) – Recalculate the schedule重新计算进度
期估计？
Activities that are near term.（近期内的活动） Activities that have long estimated durations.（工期估计 长的活动）
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缩短活动的工期估计
Reducing the Estimated Durations
Apply more resources.投入更多的资源 Assign a person with greater expertise to perform or help with the activity.指派一位经验更丰富的 人去完成或帮助完成该项活动 Reduce the scope or requirements for an activity. 缩小活动的范围或降低活动的要求 Increase productivity through improved methods or technology. 通过改进方法或技术提高劳动生 产率
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Real World Example
Vignette: Pinnacol Assurance – A Denver-based Medical Insurance Provider (page 122) Current system was a disaster with huge backlogs and daily overpayments of more than $5,000. A new project was started with a six month time frame and a development staff of two dozen. No project management principles were applied and the project spiraled out of control. Twelve months later nothing had been delivered and jobs were on the line. A project re-start was initiated with clear objectives and controls. This time the deadline never budged!
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Approaches to Schedule Control (Cont.)
Reducing durations of activities usually results in an increase in costs or a reduction in scope.缩短活 动的工期通常会导致成本的增加或范围的缩小 进度控制的关键是尽可能早地发现和处理有负 时差或时差变坏的路径。 尽早处理进度 Schedule Control
Learning Objectives
Perform the steps in the project control process Determine the effects of actual schedule performance on the project schedule Incorporate project changes into the schedule Calculate an updated project schedule Control the project schedule
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进度控制的依据
进度控制要以项目进度计划、进展报告 、变更请求和进度管理计划为依据。 项目进度计划通常以表格形式或图形形 式(网络图、甘特图、里程碑图)表示出来
表格形式 的进度计 划
里程碑图：可以用很多方式在里程碑图上显示项目
信息，如下图(△表示计划的，▼表示实际的)，但里程 碑图仅标示出主要可交付成果级别的开始和完成时间 以及关键的外部界面
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Real World Example
Vignette: Mars Pathfinder (火星探索之路page 114) Motto: Better, faster, cheaper Three year development cycle with a $150 million cost cap, managed by Jet Propulsion Laboratory. Critical 30 day launch window occurs only every 26 months. Project completed on-time and under-budget. 2.5 gigabytes of data; nearly 17,000 camera images; and 8.5 million individual temperature, pressure, and wind measurements were recorded.
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测量项目的实际进度
测量实际进度
– 了解项目各项活动的实际持续时间 – 了解各项活动的实际开始和结束时间 – 了解哪些活动已经完成，哪些尚未完成
记录实际进度
– 将上述了解到的情况和数据记录在项目进度计 划之中，如甘特图、网络图、活动清单等。 – 记录的方式多种多样
图：第5天下班检查时的网络图
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Incorporating Project Changes into the Schedule
Changes might be initiated by the customer or the project team, or they might be the result of an unanticipated occurrence. The degree of impact may depend on when the changes are requested. When the customer requests a change, additional costs might need to be charged.
Effects of Actual Schedule Performance
Actual finish times (AFT) of completed activities will determine the earliest start and earliest finish times for the remaining activities.
A change in the estimated duration of any activity will cause a corresponding change in the slack for that path. 进度分析应该包括识别关键路径 任何有负时差的活动 关键路径、任何有负时差的活动 关键路径 路径、与以前进度计划相比时差变坏的路径 路径 时差变坏的路径 加速项目进度的重点应放在有负时差的路径上，采取措 有负时差的路径上， 有负时差的路径上 施消除负时差（减少有负时差路径上活动的工期估计） （减少有负时差路径上活动的工期估计） 为减少活动路径上的负时差，选择哪类活动减少其工
表：第5天下班检查时实际进度记录 (时间单位：天)
进度偏差分析
在测量和记录之后，就要将实际进度同计划进 度进行比较。下表是第5天下班时的比较结果 比较时，首先要注意关键活动的情况，然后再 看非关键活动。看看是否有延误者。