resources are identified
and the project begins to
assume its final form. It
pertains to the fact that the
project logic—which was
derived without regard to
who is executing tasks—
could easily create a situa-
tion where a specific task
performer may be expect-
ed to work on several
tasks during the same
period of time. This diffi-
culty must be alleviated
through a technique called resource leveling.
Calculating the Critical Path
Once you’ve prepared your final schedule, you’ll naturally begin
thinking about how you’re going to maintain control and keep
the project on schedule. Now is the time to start thinking about
the critical path concept. Study the schedule illustrated in Figure
7-11. Do you notice that there’s one set of activities that are
continuously tied together with no breaks between them? This is
the critical path.
Although the critical path is fairly obvious in this schedule,
it’s much more difficult to spot on larger projects. Normally, an
actual calculation is required to determine the critical path. But
since nearly all scheduling software packages calculate the criti-
cal path for you, I won’t spend any time working through the
details of how these calculations are made. Briefly, the critical
path is derived by performing two manipulations of the sched-
ule—a forward pass and a backward pass. The forward pass cal-
culates the earliest times (or dates) that activities can start and
finish. The backward pass calculates the latest times (or dates)
that activities can start and finish. Figure 7-12 illustrates how
these calculations may be shown on a simple network diagram.
Preparing a Detailed Project Plan: Step by Step 131Resource levelingA
scheduling technique that
addresses the problem of
over-committed resources by adjust-
ing the project schedule (typically by
extending it) when the schedule logic
places demands on a resources that
exceed their availability. For example,
if Activity X and Activity Y were two
parallel activities that identify Joe as
the required task performer, resource
leveling would probably place the two
activities in series, thus allowing Joe
to work on both.