Building contingency into project plans
What is the best way to manage tasks that have a high degree of uncertainty in the duration? An example might be resolving a design problem – sometimes they are quick, sometimes they take a while.
A previous software we used, allowed you to put in a best case and worst-case estimate for each task – effectively adding contingency for each task depending on the level of uncertainty for each one. The software then added all these little contingencies together and added a portion of this (default was 50%) to the end of the project as a contingency buffer.
The benefit of this was that you had a very accurate handle on how much contingency you needed, and you could track how much of this contingency buffer you had used up at any stage of the project and therefore, what the likelihood of hitting your target date was.
In R&D a lot of our tasks have a high level of uncertainty so giving a single date is tricky unless we just go conservative all the way, which is valid, but then people freak out that the project is too long.