Topic 6.9: Dependency hierarchy
Beginning work on a building’s foundation before the detailed design is complete is common in the construction industry.
After all, the foundation is unlikely to change when the architect is down to deciding which windows and kitchen cabinets to use.
To make the most of fast-tracking, look at the longest tasks on the critical path first.
These provide the largest potential decrease in duration with the smallest number of risks to manage.
Moreover, by fast-tracking only a few long tasks, you have fewer actual changes to make, and fewer impacts on the subsequent activities.
You should then look at all your finish-to-start dependencies, and see if these can be changed to start-to-start.
If they can be changed, ask how much lead (or lag) time is required between starts?
You can even schedule tasks concurrently, as long as they use different resources and the risks are acceptable.
Remember too that there may be a large number of tasks in your project that have no dependencies.
If that is the case, you should be able perform these tasks concurrently, in any order and at any time – unless, of course, there is a dependency hidden there that we do not yet understand (as in the earlier case of our excavator)!