IT project management consultants and Project Management Office
(PMO) managers see project schedules that vary in quality. A PMP certified project manager (PM) may have 10 years of experience managing
projects, but that isn’t an indicator of the PM’s ability to build a good
schedule.
Evaluating a project schedule can be subjective unless there is
a set of objective criteria to follow. Well-structured PMO organizations may
have project schedule quality guidelines, but unless there’s a schedule review,
the schedule could still have significant defects that impact realistic project
delivery. (Remember: The project schedule is a forecasted model of future
events, so you want the model to reflect reality as much as possible.)
The Defense Contract Management Agency (DCMA) provides a 14-point assessment
that can be applied to evaluate project schedule quality. The DCMS is a
Department of Defense (DoD) department that works with suppliers to manage
time, cost, and performance for the U.S. federal government.
Pre-assessment metrics
You need to calculate these metrics before applying the quality
checks.
- Total Tasks is a
count of the lowest level tasks, excluding summary, subproject, zero baseline
duration, and milestone tasks. - Complete Tasks is
a count of Total Tasks with an Actual Finish date. - Incomplete Tasks is
a count of Total Tasks without an Actual Finish date. - Baseline Count is
a count of all the Total Tasks that should have completed on or before the
project status date. - BEI Baseline Count
is a count of all the Total Tasks that should have completed on or before the
project status date and all the tasks that are missing a baseline start and
finish date. - Relationship Count is a count of all the Finish-Start (FS), Start-to-Start (SS), Start-Finish (SF), and Finish-to-Finish (FF) dependencies in the schedule.
The 14 quality checks
- Logic Check evaluates if any tasks are missing a successor
or a predecessor in the schedule.
Logically, all activities should have at least one predecessor or
successor tasks or else you risk creating an orphaned task. A quality schedule
should not have more than 5% of its tasks missing logic. The logic check
formula is (# of Tasks missing Logic) / (# of Incomplete Tasks) * 100. - Leads Check looks for negative lags (i.e., leads) in the
schedule. A quality schedule should have zero leads, as they can impact a
project’s critical path. - Lags Check ensures the use of lags is minimized in
the project schedule, as lags can impact the critical path. A quality schedule
would have fewer than 5% of the tasks with lags. The lag check formula is (# of
Tasks with Lag) / (Incomplete Tasks). - Relationship Types Check validates 90% of the
tasks have Finish to Start relationships.
Using Finish to Start relationships provides a logical flow to the
schedule. - Hard Constraints Check is any activity that has a
Must Finish On, Must Start On, Start No Later Than, or Finish No Later Than
constraint. You often see these constraints in the “pick-a-date”
project management. You ideally want your schedule to be a dynamic schedule
that flows easily when the project is updated. The hard constraints check
identifies any Incomplete task that has a hard constraint. A quality schedule
will not have more than 5% of its tasks with hard constraints. - High Float Check identifies all tasks with a total
float of more than 44 working days. A task with such a high float usually
indicates a predecessor or a successor was missing. The formula is (# of High Float
tasks) / (# of Incomplete Tasks). The percentage should not exceed 5%. - Negative Float Check identifies any tasks that have
a float less than zero. This check helps identify any tasks that may hinder the
completion of other tasks in the schedule. There should be zero tasks with
negative float. - High Duration Check identifies any task that has a
baseline duration greater than 44 days.
As competent PMs, we know such tasks should be broken down into more
discrete tasks. The formula is (# of High Duration tasks) / (# of Incomplete
Tasks) and should not exceed 5%. - Invalid Dates Check identifies any total task that has a
scheduled start or finish date before the project status date and an actual
start or finish date after the project status date. Forecasted start and finish dates should always
appear after the project status date. The schedule also can’t contain an actual
start or finish date in the future. There should be zero tasks that fall into
this category in a quality schedule. - Resources Check identifies all the tasks that do not have
resources (people or costs) assigned. A quality schedule has all resources
assigned to tasks in the schedule. - Missed Tasks Check is used to identify any task
that was scheduled to complete by the project status date and finished after
the baseline finish date. The reality is projects will have late tasks, but you
want to ensure your current schedule re-aligns to the baseline schedule. The
formula is (# of tasks with forecasted finish before the status date and actual
or forecasted finish after baseline schedule date) / (baseline count). - Critical Path Test Check assesses the integrity
of the schedule network using the critical path. An intentional delay of 600
days is entered into the remaining duration of a critical path test. The
expected result is the project is delayed by 600 days since you added a delay
directly on the critical path. The schedule passes the test if the project
finish date matches the added duration date finish date. - Critical Path Length Index (CPLI) determines if
the project finish date is realistic given the forecasted finish date. The
critical path length index is calculated using the formula (Critical Path Length + Total Float) / (Critical Path Length). The value should be greater than 1.0 to pass the test. - Baseline Execution Index (BEI) is similar to Earned
Value’s Schedule Performance Index as it compares the number of completed
activities to date to the number of tasks planned to be completed by the
project status date. The BEI is calculated # of Complete Tasks / BEI Baseline
Count and should be greater than 1.0.
Summary
You can use these
quality checks as a framework to evaluate and review project schedules. The criteria can also help you evaluate
how well a supplier can build and execute a meaningful schedule.
As a project
manager, I’ve seen my share of bad schedules, and I’m sure I’ve built a poor
schedule every now and then. The DCMA criteria serve as a useful schedule
quality gauge that eliminates subjective evaluations.
In my next
article, I’ll show how to automate some of these quality checks in your Microsoft
Project schedule.
