In general terms, schedule analysis performed during the project is considered prospective; when undertaken after project completion, it is retrospective. Forensic schedule analysis is defined as retrospective analysis that examines the schedule for later or earlier completion, identifies related disruption and acceleration, and apportions delay and gain and the associated additional costs.
Forensic scheduling was acknowledged as a technical field distinct from project planning and scheduling in 2007 when AACE International issued Recommended Practice No. 29 Forensic Schedule Analysis (RP 29). RP 29 signaled the arrival of forensic scheduling as the knowledge successor to the prior art of delay analysis.
Leading the Way
In 2010, CEO Dr. Gui Ponce de Leon, in collaboration with other senior PMA leaders, published the Guide to the Forensic Scheduling Body of Knowledge—Part 1, which extends RP 29 and other standards. With over 20 years of experience collaborating on project work and forensic scheduling, the authors were uniquely positioned to compile existing and emerging principles and methods into this authoritative guide.
Forensic Float
Once actual dates are introduced into a CPM schedule, the CPM scheduling algorithm ceases to function left of the data date. Total floats cannot be calculated with the CPM equation of late finish date (or actual finish) minus early finish date (or actual finish). With CPM unable to calculate total floats in the past, the critical path cannot be mathematically generated for the progressed portion of the schedule (left of the data date), or for the as-built schedule, without using work-around methods and potentially impairing accuracy of the analysis.
FSBOK Example Pages
The Graphical Path Method (GPM), pioneered and developed by Dr. Ponce de Leon, retains float left of the data date and is inherent to the GPM algorithm.
For more in-depth coverage of GPM, including the calculation of total floats and the location of the critical path left of the data date, browse the resources below, see the GPM tab, or visit PMA Technologies.