Project Schedule Control

The key to effective project schedule 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.Involving regularly gathering data on project performance and comparing with the planned performance, project schedule control is concerned with influencing the factors that create schedule changes to ensure that changes are agreed upon, determining that the schedule has changed, and managing the actual changes when they occur.Schedule control must be thoroughly integrated with other control processes.

Inputs to Schedule Control

Project Schedule

The project schedule, called the schedule baseline, which must be feasible both technically and in terms of resources, is a component of the project plan.It provides the basis for measuring and reporting schedule performance.

Performance Reports

Performance reports provide information on schedule performance, such as which planned dates have been met and which have not.Performance reports may also alert the project team to issues that may cause problems in the future.

Change Requests

Change requests, occurring in many forms—oral or written, direct or indirect, externally or internally initiated, legally mandated or optional, may require extending the schedule or may allow accelerating it.

Schedule Management Plan

The schedule management plan is described in the part of “Project Schedule Planning”.

Tools and Techniques for Schedule Control

Progress Reporting

Once the schedule baseline is agreed with the customer the project starts.Progress reporting is needed to detail the actual start and finish dates of activities and the remaining duration of unfinished activities.A regular reporting period should be established for comparing the actual progress with the planned progress.Reporting may be daily, weekly, or monthly depending on the complexity and the duration of the project.During each reporting period, two kinds of data or information need to be collected.One is data on actual performance, and the other is information on any changes to the project scope, schedule or budget.It is a good idea to include the percent completion of activities in the progress report.

Performance Measurement

Performance measurement techniques are used to assess the magnitude of variation to the original schedule.An important part of schedule control is to decide if the schedule variation requires corrective action.For example, a major delay on a noncritical activity may have little effect on the overall project, while a much shorter delay on a critical or near-critical activity may require immediate action.Some common performance measurement tools include schedule comparison bar charts, project management software, schedule change control systems, schedule variance and schedule performance index.

Variance Analysis

Performance of the variance analysis during the schedule monitoring process is a key element for schedule control.Variance analysis compares planning data with actual performance in order to discover delays or variations in the project schedule.For example, the planned start, duration, and anticipated completion date would be compared with the actual start date, duration, and completion date for that activity.The float variance is also an essential planning component to evaluate project schedule performance.Particular attention should be paid to critical and subcritical activities.

Outputs from Schedule Control

Schedule Updates

A schedule update is any modification to the schedule information that is used to manage the project.Appropriate stakeholders must be notified as needed.Schedule updates may or may not require adjustments to other aspects of the project plan.

Corrective Action

Corrective action is anything done to bring expected future schedule performance in line with the project plan.Corrective action in the area of time management often involves expediting, which means that special actions should be taken to ensure completion of an activity on time or with the least possible delay.Corrective action frequently requires root-cause analysis to identify the cause of the variation, and schedule recovery can be planned and executed for activities delineated later in the schedule.

Lessons Learned

The causes of variance, the reasoning behind the corrective action chosen, and other types of lessons learned from schedule control should be documented, so that they become part of the historical database for both this project and other projects of the performing organization.

Reasons for Schedule Slippage

With all of this practice in project scheduling, one would think that all projects are well-scheduled and that they finish on time.However, experience indicates that projects often, even usually, overrun their schedules.

Cashman concluded in 1995 that schedules may slip due to at least four problems commonly associated with project scheduling.

• Project scheduling is difficult.It is clear to anyone who has dealt with projects that scheduling is a demanding discipline that is not mastered by all those who are assigned scheduling responsibility.
• The rules of project scheduling are not clear or practicable.It means that the use of logic, constraints, resources, calendars and activity durations are not always clear to the scheduler, nor are they followed in practice.Poor scheduling practice can lead to imperfect and sometimes dangerous project schedules.
• Management or the project’s owner will often insist on unrealistic deadlines.The scheduler often is not permitted to produce the schedule that can be accomplished with the resources at hand.
• Project schedules are built using single-point (deterministic) estimates of activity durations.When the uncertainty of future durations is taken into account, the duration of a schedule path is likely to differ from that computed by CPM scheduling.

Exercises

I.Decide whether the following statements are true(T) or false(F) according to the passage.

1.Project schedule management refers to a component of overall project management in which a timetable is analyzed and developed for proliferating a project or deliverable.

2.Gantt charts can effectively cope with a number of activities, data, and dependencies between involved in large projects.

3.You can ensure that the project plan is flowing illogically by using the network diagram, particularly during the design phase of a project.

4.The project schedule, called the schedule baseline, is a component of the project plan.It provides the basis for measuring and reporting schedule performance.

5.Duration estimate is mainly the responsibility of the project manager where team members needn’t be involved early.

6.Resource optimization is achieved by a systematic utilization of the floats of critical activities.

7.The critical path is defined as the shortest logical path through the project network diagram, which can not be shortened again.

8.The ES and EF for each activity are found by calculation performed in sequence from right to left in the network, called backward pass.

9.Project schedule control involves influencing the factors that create schedule changes to ensure that changes are agreed upon, determining that the schedule has changed, and managing the actual changes when and as they occur.

10.If the network diagram is developed properly, the total completion of the project can be obtained from the diagram as equal to the time period between the early start date of the first activity and the late finish date of the last activity by following a particular path.

II.Professional terms translation.

工作分解结构　工期优化

关键路径　活动排序

计划评审技术　网络图

进度控制　工作包

箭线式网络图　里程碑

III.Fill in the blanks.

1.Project schedule management refers to a component of overall project management in which a_____is analyzed and developed for the_____of a project or deliverable.

2.The main tool required for the definition of an activity as well as the determination of the duration and sequence of activities is the_____.

3.In both the_____and_____sequencing situations, it is incumbent on the skills of the project team to make the appropriate activity sequencing decision.

4.______is the total number of the work periods required to complete a schedule activity.

5.Project schedule planning requires project-wide conception and project team commitment to______events.

6._____ _____compares planning data with actual performance in order to discover delays or variations in the project schedule.

7.AOA diagrams, as the name implies, have_____representing the activities and any special information can be annotated to the arrows.

8.Three-point estimates are based on using_____,_____,and_____estimates of activity durations instead of one specific or discrete duration estimate, as CPM does.

9.The critical path is defined as the_____logical path with_____float through the project network diagram.

10.In large and complex projects, the complementary use of_____charts and_____charts may be a very smart strategy.

IV.Match the following words or expressions with their meanings.

V.The following sentences are given in a wrong order.Reorganize these sentences into a coherent paragraph.

( ) There are two important management considerations for sequencing.

( ) In these cases, the project manager may sequence them to accommodate availability of resources, weather, or other factors.

( ) That is, many activities can be performed at various times.

( ) In both the technical and arbitrary sequencing situations, it is incumbent on the skills of the project team to make the appropriate activity sequencing decision.

( ) Firstly, there is a concept called technical sequence, which is based on the technology of the project.

( ) However, it is important to recognize that these decisions do impact the schedule results, so sequencing considerations are often interactive ones until the plan is fixed.

( ) A second consideration of sequencing falls behind the technical issues.

VI.Paragraphs translation.

1.The main tool required for the definition of the activity as well as the determination of the duration and sequence of activities is work breakdown structure (WBS).The WBS definition from PMBOK Guide reads: “The WBS is a deliverable-oriented grouping of project elements which organizes and defines the total scope of the project.Each descending level represents an increasingly detailed definition of a project component.Project components may be products or services.”

2.Keep in mind that the network diagram represents activities that must be done to complete the project.It is not a race to get from the first node to the last node.Every activity on the network diagram must be completed in order for the project to finish.It is also important to note that not every single item on the WBS needs to be on the net work diagram; only activities with dependencies need to be shown on the network diagram.However, some people like to have start and end milestones and to list every activity.It is a matter of preference.For projects with hundreds of activities, it might be simpler to include only activities with dependencies on a network diagram, especially on large projects.Sometimes it is enough to put summary tasks on a network diagram or to break down the project into several smaller network diagrams.

3.In large and complex projects, the complementary use of Gantt charts and CPM charts may be a very smart strategy.The latter effectively cope with a number of activities, data, and dependencies between involved.They, however, do a poor job of showing to project members in a simple and visual manner what activities to work on in the next week or the next two weeks.That is where Gantt charts may step in.Extracting from the sizable CPM chart activities due in the next week or two, presenting them in Gantt charts, and handing to the people involved provide clear and practical partial short-term outlook schedules.Those in management will still be responsible to coordinate the interfaces between the owners of the schedules.

VII.Sentences translation.

1.项目进度管理包括活动定义、活动排序、活动历时估算、进度计划和进度控制。

2.活动定义是指识别和定义完成项目各种可交付物所必须进行的各项具体活动，而活动排序则是要识别和确定各活动之间的逻辑关系或依赖关系。

3.活动资源估算的结果就是要确定每个活动所使用的资源类型和资源数量。

4.关键路径上的活动的持续时间决定项目的工期，关键路径上所有活动的持续时间加总就是项目的工期。

5.工作分解结构是实施项目必须进行的全部活动的一张清单，也是进度计划、人员分配、资源分配、预算计划的基础。

6.项目是由各个任务构成的，每个任务都有一个最早、最迟的开始时间和结束时间，如果一个任务的最早和最迟时间相同，则表示其为关键任务。

7.工期、费用和质量是项目的三大目标，而工期，或者说进度又是最核心的。

8.在项目管理进度跟踪的过程中，只要能保证里程碑事件的按时完成，整个项目的进度也就有了保障。

9.项目进度计划是控制项目进程的最主要的纲领性文件，也是其他项目计划的基础和指导性文件。

10.控制项目进度并不意味着一味追求进度，还要满足质量、安全、经济的需要。

VIII.Discussion.

Topic One: How many steps does project schedule management contain? What is the function of each step?

Topic Two: List some methods for project schedule planning, and point out their strengths and weaknesses.

Topic Three: Discuss how to optimize a project schedule planning.

IX.Project management treasury.

Henry Gantt

Henry Gantt (1861—1919), was an American mechanical engineer and management consultant who was most famous for developing the Gantt chart in 1910s.Gantt charts were employed on major infrastructure projects including the Hoover Dam and Interstate highway system and continue to be an important tool in project management today.

Gantt was born in Calvert County, Maryland.He graduated from McDonough School in 1878 and then went on to Stevens Institute of Technology in New Jersey.He then worked as a teacher and draughtsman before becoming a mechanical engineer.In 1887, he joined Frederick W.Taylor in applying scientific management principles to their work at Midvale Steel and Bethlehem Steel, working there with Taylor until 1893.In his later career as a management consultant, following the invention of the Gantt chart, he also designed the task and bonus system of wage payment and additional measurement methods to improve workers’ efficiency and productivity.

Gantt created many different types of charts.He designed his charts so that foremen or other supervisors could quickly know whether production was on schedule, ahead of schedule, or behind schedule.Modern project management software includes this critical function even now.

Besides Gantt charts, Henry Gantt’s legacy to management includes the following: industrial efficiency, the task and bonus system and the social responsibility of business.

Due to his outstanding contribution to management, the American Society of Mechanical Engineers (ASME) awards an annual medal in honor of Henry Gantt.