The basic rules are as follows:

We will make two passes through the information. The first starts with the first task's ES and works down each task. The second pass starts at the last task's LF and works toward the top. Pass 1—Start with first task

1. If task has no predecessor, then ES = 0

2. If task has one predecessor, then ES = Predecessor's EF

3. If task has more than one predecessor, then ES = MAX(EF of all Predecessors)

5. Repeat 1-4 for all tasks

6. Project Duration = Maximum(EF of all Task)

Pass 2—Start with last task

1. If task has no successor, then LF = Project Duration

2. If task has one successor, then LF = LS of successor

3. If task has more than one successor, then LF = Minimum (LS of all Successors)

6. Repeat 1-5 for all Task

From Pass 1 we know the project duration. From Pass 2 we know the critical path.

Any task with a slack of 0 means that we cannot change its start or stop without changing the overall project duration. Those task with slack mean that we can delay the task start by as much as the slack and not change the project duration. Start with a blank table as shown in Table 3-17. We will begin in Task A under ES.




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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