Planning and controlling projects through Microsoft Project schedules that use precedence diagramming method and critical path method for all of your major initiatives is itself a major accomplishment that proves that your organization is maturing in its project management practice. However, a purely deterministic scheduling approach tends to yield schedules that represent best-case scenarios. Overruns are still the norm. So how do you build lean schedules that encourage high-performance and that are achievable time and time again?
In a presentation from the Microsoft Project Conference 2012 conference I explored the limitations of universally adopted planning processes. My recommendation is to consider pushing beyond them by leveraging simple yet powerful probabilistic and stochastic scheduling approaches to performance-tune your scheduling methods. I’ve written a Program Evaluation and Review Technique (PERT) macro for Microsoft Project 2010 that’s a self-documented text file that easily becomes a powerful Project macro add-in. As a two-step process, the PERT macro first supports simple PERT and more advanced project duration estimating techniques that help you to develop a mean-based performance baseline.
The PERT macro then applies standard distribution theories to help you forecast the probability of completing a project within given target duration objectives. It will help you determine necessary project contingency as you negotiate with your project sponsor the right balance between risk and reliability.