Once we decide which path we wish to eliminate we then examine all of its tasks to see if durations are correct or can be reduced.
For example, by adding more labour, working more efficiently, reducing the scope of the task.
A project should only have one critical path.
The Project Manager does not want to be focussing on more than one critical path.
There are a few key tactics to use when trying to eliminate one of multiple critical paths.
These are fairly straight forward to do but in practice will require careful consideration.
The first is to alter one or more task durations.
This can be done either by reducing a task duration (so that they are no longer critical, for the path not desired) or extending the task duration (so that the tasks remain critical, for the desired path).
By definition extending any task on an already critical path will extend the project completion date.
As with any such strategy there has to be careful consideration:
It may not always be possible to reduce a duration.
If the tasks are fixed in duration then extra resource will not help.
Extending a task is physically easy but may have ramifications for other dependent tasks.
The first question to ask will be, ‘Is it possible?’
This should lead into a discussion of options.
The ramifications of any adjustments must then be fully explored to check if it would be desirable.
By extending the end date you would in effect remove all critical paths by introducing float into the final tasks.
In order to restore one critical path you will need to extend the duration of one or more of its tasks so that any float is eliminated.
It may be necessary to review all of the dependencies on the critical path.
If these change then it may make one pathway non critical and in effect promote another to be the only one.