A significant difference between the CPM Project network and the PERT network is:

The PERT method enables calculation of expected project completion based on

task variation; The CPM method does not allow for task variation nor expected

project completion.

The CPM network accounts for task and project variation; PERT allows for task

variation but does not provide a way to consider project variation.

The CPM method enables calculation of expected project completion based on task

variation; while PERT does not provide a way to consider task variation.