Difference between Crashing and Fast Tracking.

Hi All,

I have been trying to understand the difference between Crashing and
Fast tracking. Following are my understanding and questions:

Fast tracking means that you look at activities that are normally done
in sequence and assign them instead partially in parallel. If you were
fast-tracking, you would start constructing the solution in areas where
you felt the design was pretty solid without waiting for the entire
design to be completed.

"Crashing" the schedule means to throw additional resources to the
critical path without necessarily getting the highest level of
efficiency. For instance, let’s say one person was working on a ten-day
activity on the critical path. If you were really desperate to shorten
this timeframe, you might add a second resource to this activity.

Similarities are:
1) Both the approaches are aimed at reducing the schedule
2) Both the approaches require addition of resources to achieve the goal
3) Even though fast tracking doesn't mention the term Critical Path,
it's obvious that the Critical Path tasks need to be done in parallel
to reduce the schedule. So, both the approaches involve changes to
Critical Path activities schedule.

Given the above, both of them looks similar with no subtle difference.
But, the two different terms should have been created for a purpose,
that i might be missing here.


admin's picture

What you have mentioned above is correct and that is precisely the difference between crashing and fast tracking.

Fast Tracking - doing activities in parallel

Crashing - Throwing more resources.

Both are schedule crunching mechanisms.


- Fast tracking can increase project 'risk' and might cause the project team to have to rework tasks.

- The idea with crashing is to try to gain the greatest amount of schedule compression with the least amount of 'cost'.


The bullet 1 you mentioned is right, both are aimed to reduce the schedule. This is done when you want to anticipate a major milestone or the project final date, but also when you have delay problems.


The bullet 2, is not necessarelly true. When you use fast tracking, you MAY add resources, but you may also just antecipate resources or just work overtime. But the main point is that using crash, you add resources to the SAME activity (you have more people doing the same work), and in fast tracking you allocate people to antecipate other tasks. The risk and the way you manage this is pretty different.


About bullet 3, yes, you need to FIRST look at the critical path. But when you crash or fast track the CP, you may chage and a new task may become part of the critical path. So, you have to start looking to other tasks that are not in your schedule baseline.

Just to finish, is not necessarelly true that the cost increases when you crash the schedule. If you just "shift" resources, changing the time table they were suppose to act upon, you just change the EV curve, and maybe the cash workflow. If you have to hire additional resources, then yes, you have cost increase.

Just kep this in mind: Crashing involves changing the duration of the task and the critical path. Fast tracking involves changing just the duration of the critical path (not the duration of each task).

And you may use both of them at the same time (shortening duration of tasks and critical path, by applying both methods)

See ya !!

Robledo Castro, MSc, CSM, PMP