Anyone who has ever had to prepare for a theoretical examination in project management certainly knows that network planning is rarely used in practice. Nevertheless, it makes sense to understand the logic behind it.
In general, network planning aims displaying all tasks and their dependencies graphically in the project.
What are the Objectives of Network Planning?
- Determination of project duration
- Determination of the Critical Path
- Determination how to speed up a project (if necessary)
- Basis for scheduling
What is a Network Node?
In addition to the task name, a node contains task information such as Early Start, Late Start, Early Finish and Late Finish. In addition the task duration is indicated and the buffer time (float).
Buffers are time reserves (between the tasks) in the project which are helpful when tasks are delayed. Buffering minimizes the risk of the project end being postponed when individual tasks are delayed.
- Free Float = Early Start Task 2 – Early Finish Task 1 (ES2 – EF1)
- Slack = Late Start Task 2 – Early Finish Task 1 (LS2 – EF1)
The free float buffer specifies how much an task can be delayed without moving the successor from its earliest location.
Slack (Total buffer)
The total buffer specifies how much an task can be delayed without moving the successor from its latest position. If the total buffer is equal to zero, the process is critical. If an task is further delayed, the entire project end is delayed.
BlueProjectHero software includes this kind of network diagram and displays the total buffer of the individual tasks (see the following graphic).
In the next article, we will discuss the Critical Path and explain it in detail.