Free Float

If a computer is not available, free float on an arrow diagram can be ascertained by inspection, since it can only occur where more than one activity meets a node. This is described in detail in Chapter 21 with Figures 21.5 and 21.6. If the network is in the precedence format, the calculation of free float is even easier. All one has to do is to subtract the early finish time in the preceding node from the early start time of the succeeding node. This is clearly shown on Figure 24.9, which is the precedence equivalent to Figure 24.1.

One of the phenomena of a computer printout is the comparatively large number of activities with free float. Closer examination shows that the majority of these are in fact dummy activities. The reason for this is, of course, obvious, since, by definition, free float can only exist when more than one activity enters a node. As dummies nearly always enter a node with another (real) activity, they all tend to have free float. Unfortunately, no computer program exists which automatically transfers this free float to the preceding real activity, so that the benefit of the free float is not immediately apparent and is consequently not taken advantage of.

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Project Management Made Easy

Project Management Made Easy

What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.

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