The
Near-Critical Path
Identification of near-critical paths that have a reasonable
probability of becoming critical is a key outcome of Monte Carlo simulation. For
many project managers, the near-critical path identification is perhaps the most
important outcome. In fact, during the course of the Monte Carlo simulation,
depending on the distributions applied to the critical tasks and the
distributions applied to other paths, there will be many runs, perhaps very many
runs, where the critical path identified by straightforward CPM calculations
will not in fact be critical. Some other path, on a probabilistic basis, is
critical for that particular run. Most Monte Carlo packages optimized for
schedule applications keep careful record of all the paths that are, or become,
critical during a session of runs. Appropriate reports are usually
available.
Project managers can usually specify a threshold for
reporting the near-critical paths. For example, perhaps the report contains only
information about paths that have a 70% confidence, or higher, of becoming
critical. Setting the threshold helps to separate the paths that are nearly
critical and should be on a "watch list" along with the CPM-calculated critical
path. If the schedule network is complex,
such threshold reporting goes a long way in conserving valuable management
time.