Phantom Float and the Resource Critical Path

In a prior article, we explored how to develop a resource-feasible schedule, one in which resources are not over allocated.  The process for leveling is straight forward and the use of various leveling heuristics guarantees that scheduling software like MS Project can find a solution quickly, even though the result might not be optimal.   However, resource-constrained scheduling (RCS) has a troublesome side-effect:  phantom float.  Further, the length of the leveled schedule may be driven not by one or more logical critical paths, but by one or more resource critical paths (RCP’s).  These resource critical paths are a byproduct of the leveling, as well.   We will take a look at both of these phenomena in this article.    Continue reading “Phantom Float and the Resource Critical Path”