《Fundamentals of Project Management 4th Edition》 读书笔记 第七章 为项目工作安排进度

CHAPTER 7 Scheduling Project Work

 

1958年，出现了甘特图，但甘特图不能显示任务间的依赖性，所以就不能够判断一个任务延期后给整个项目带来的影响。

Until around 1958, the only tool forscheduling projects was the bar chart. Because Henry Gantt developed a completenotational system for showing progress with bar charts, they are often calledGantt charts. They are simple to construct and read and remain the best tool touse for communicating to team members what they need to do within given timeframes. Arrow diagrams tend to be too complicated for some teams. Nevertheless,it is often helpful to show an arrow diagram to the people doing the work so thatthey understand interdependencies and why it is important that they complete certaintasks on time.

Bar charts do have one serious drawback—itis very difficult to determine the impact of a slip on one task on the rest ofthe project. The reason is that the bar chart (in its original format) did notshow the interdependencies of the work.

 

后来出现了CPM呵PERT，但现在PMI用的就叫箭头图。

To overcome this problem, two methods ofscheduling were developed in the late 1950s and early 1960s, both of which usearrow diagrams to capture the sequential and parallel relationships amongproject activities. One of these methods, developed by Du Pont, is calledCritical Path Method(CPM), and the other, developed by the U.S. Navy and theBooz Allen Hamilton consulting group, is called Program Evaluation and ReviewTechnique (PERT).

 

进度安排目的是保证项目截止期限被满足。以及判断哪些任务处于关键路线上。

Naturally, the primary reason forscheduling a project is to ensure that the deadline can be met. Most projectshave a deadline imposed. Furthermore, since the critical path method helpsidentify which activities will determine the end date, it also helps guide howthe project should be managed.

 

纸上设计的进度安排未必适用于实践。还要考虑资源的可用性。

It is also very easy to create schedulesthat look good on paper but don’t work in practice. The main reason is usuallythat resources are not available to do the work when it comes due. In fact,unless resource allocation is handled properly, schedules are next to useless.

 

如果项目范围没有事先定义好，则进度安排往往会变更。如果任务的优先级经常变化，也会影响进度安排。

There are two points worth consideringhere. One is that if scope is changing often in a project, not enough time isbeing spent doing upfront definition and planning. Scope changes most oftenoccur because something is forgotten. Better attention to what is being done inthe beginning usually reduces scope creep. Second, if priorities are changingoften, management does not have its act together.

 

安排进度时要充分考虑到资源的因素，没有足够的资源，任务就没有办法开展。也不能同时给一个资源分配了多项任务，这样会显著降低效率。

Generally, the organization is trying to tackletoo much work for the number of resources available. We all have “wish lists”of things we want to do personally, but we have to put some of them on holduntil time, money, or both become available. Experience shows that when youhave individuals working on many projects, productivity suffers.

 

不要给任务分配超过6周的周期。对于知识型工作，最好周期在1到3周，因为知识型工作比有型的工作更难以跟踪。

No task should have duration much greaterthan four to six weeks. For knowledge work, durations should be in the range ofone to three weeks, because knowledge work is harder to track than tangible work.

 

可从前至后安排，也可从后至前进行安排进度。

There are two ways you can develop aschedule. One is to begin at the end and work back until you arrive at thebeginning. The second method is to start at the beginning and work toward theend. Usually, it is easiest to start at the beginning.

 

进度安排在逻辑上要合理，然后再进行资源分配。

Schedules should be developed according towhat is logically possible, and resource allocation should be done later. Thiswill yield the optimum schedule.

 

所有的任务都应该有相同的时长单位。

Another rule is to keep all times in thesame increments. Don’t mix hours and minutes—schedule everything in minutes, thenconvert to hours and minutes as a last step.

 

对已进度安排，没有唯一的答案，但有的安排会在逻辑上错误。

It is hard to tell whether a network isabsolutely correct, but it can be said to be wrong if logic is violated.