Schedule Analyzer SA Forensic Technical Overview
As-Built Critical Path Work Profile Technical Issues

Calendar Modified Linear Regression

SA Forensic As-Built Critical Path (without Work Profiler) uses a process that we call, “calendar-modified, linear-regression of remaining duration.” To do this, we replace the Actual Finish date with an Expected Finish constraint of the same date. Then, no matter what data date we use, P3 will automatically recompute the remaining duration to reflect the number of work days necessary for the activity to finish on the date it is destined to actually finish. This simple process is sophisticated enough to automatically consider weekends and holidays when determining estimated progress. A typical diagram of remaining duration progress might look like the following graph.

Example of a typical remaining duration diagram using CPM calendars.

The above model represents our ‘best guess’ of the actual progress of a typical activity. In this case, on May 1 we know that the activity was statused as having started and on May 19, it was statused as having finished. These two dates and statuses are known with legal accuracy. We use our stated formula for estimating the progress at any given date between these two points.

As-Built Critical Path using Work Profiles

What is the real reason that we are tracking these work profiles? For As-Built Critical Path, we are trying to compute an estimate of the activity’s progress given any date. We assume that we do not have access to an agreed-upon listing of the day-to-day progress assessment for every task. Thanks to Profile Maker (and a lot of hard work,) we do have a day-by-day Work Profile database that describes the resources and actual days work expended on a task. We compute an estimate of current progress at any date by equating progress with time and resources spent. As-Built Critical Path uses its database to substitute the actual number of days remaining for the activity in question for the Expected Finish procure above. The same process described in the earlier graph might look like the following using actual data described in a Work Profile,

Example of an actual remaining duration using Work Profiles.

Using our example, if you used the default process, on May 14 you would have estimated that 5 days were remaining for the activity in question. Using Work Profiler, you would now know that actually only 1 day remained for completion. This change in status might have resulted in another activity becoming critical than originally thought.

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