We can view the critical path in a project management schedule as what I would call the "bottleneck" of the project: it is the series of activities which determines the possibly earliest completion of the project. That means that activities on the critical path can not be delayed without jeopardizing the project end date; those activities have zero float. That means on the other side that activities not being on the critical path do have some float: these activities can be delayed to some extent without jeopardizing the project end date. This "some extent" would be the float of those activities indicating how many days those activities could move to the right without any major impact on the project end date.
Thus it becomes obvious that a project manager needs to really have the critical path on his radar screen. Activities on the critical path require highest attention since any delay here means a delay of the entire project. For that reason it is a good idea to somehow visualize the critical path in our MS Project plan !
MS Project allows to do this: you can show bars of activities on the critical path in a different color and you can highlight the task names and task information in another color ( red is the chosen default ). Here is the recipe how to do this and I also have prepared a little screen cast to demo this:
- Use the gannt chart wizard (Menu: Format -> Gantt Chart Wizard) in MS Project to specify that bars of critical tasks will be shown in red color. Simply select the "critical path" radio button and proceed through the remaining dialogs by just confirming the defaults, then hit "Format It!" and "Exit Wizard".
- Next use the "Text Styles" dialog box to specify that text for critical tasks should be displayed in red color: select "Critical tasks" from the drop down "Item To Change", then select "Red" from the color drop down, click OK to finish.
After this has been done you end up with a gantt chart like this:
In our little example here we now easily can figure out where the critical path is: specifying and design activities are on the critical path as well as integration testing, as probably expected. All SAP related activities are on the critical path as well, while we do have some float ( or slack ) for the GUI and database related activities.
How much slack we have can be seen in the "Start Slack" column: there is not too much "space to breath" for the GUI related tasks, but lots of float for the database related tasks.