Schedule Updating and Project Control - Construction Project Scheduling and Control - page 189

It is important to note that the “man-hours” unit is not a time-measuring
unit. It is, rather, a measure of effort or consumption of a labor resource. Eight
man-hours can be produced by one person during an 8-hour period, by two
persons during 4 hours, by four persons during 2 hours, and so forth.
4. Duration: Again, this method is indeed two methods—one based on baseline
and one on actual duration.
4.1 Baseline Duration:
Percent Complete =(Data Date − BL Start Date)∕Total BL Duration
Where BL Start Date is the baseline start date, that is, when the project
was planned to start.
4.2 Actual Duration:
Percent Complete = Actual Duration∕At Completion Duration
Where At Completion Duration = Actual Duration + Remaining
Duration
In Figure 7.15, the project is represented by one summary bar. There
are two bars, one representing the baseline project and the other representing
the updated project. The project started 3 days late and is expected to take 1
more day than originally planned; that is, it is expected to finish 4 days past its
baseline finish date.
Baseline Duration Percent Complete = 19∕32 = 59%
Actual Duration Percent Complete = 16∕33 = 48%
Whether the scheduler is using baseline or actual duration, the scheduler
has to make sure that he or she is counting workdays or calendar days. Both
are okay as long as the scheduler knows what he or she is measuring and is
consistent.
5. Workday unit: The workday unit method is based on the assumption that activ-
ities have weights that are proportional to their durations. As a simple example,
let's contemplate a project made up of three activities (A, B, and C); each one
Figure 7.15 Percent complete based on duration