Those performing a schedule validation should consider some common checks to confirm and validate the quality of the schedule. Even contractors working in good faith may submit a schedule that in some way is misleading and/or overly optimistic. Yes, the schedule may be well intended but not true to reality.
It is the role of the reviewer to perform some basic schedule checks before declaring the good news to project stakeholders. Whether intentional or not it is easy to obfuscate the true schedule situation. A schedule that initially looks promising may in fact be a schedule in trouble and that’s where schedule validation enters.
This article discusses some common schedule considerations to look out for when performing a schedule validation It’s not meant to be exhaustive, but certainly looks at some of the more common areas you should review.
Relationships and Lead Lag Issues
- Illogical Relationships – Be aware of inappropriate relationships that were inserted to jerry rig the start and/or completion of a task. The scheduler may also have inserted start to start (SS) or finish to finish (FF) relationships in an effort to fast track the schedule even though those types of relationships may not apply. (Note that fast tracking is taking tasks in series and performing all or some of them in parallel to shorten the project duration.)
- Lead-Lag Issues – Another way to jerry rig activity start or completion dates is to insert a lead or a lag. A lead is a negative lag, and in the finish to start (FS) relationship, for example, it says the successor may proceed a period of time before the completion of the predecessor. This neglects or violates the true FS relationship where the predecessor task must complete before commencing the successor activity. Thus, this makes the FS relationship soft at best, and at worst a violation of network logic. So the reviewer should flag insertions of negative lag.
Many times schedulers insert a positive lag to target the start of a successor activity, such as a meeting event on a specified date. But even positive lags are suspect and many times leave stakeholders wondering what the true schedule situation is. A lags purpose is usually not well-documented in most typical schedules. Schedule validation should consider carefully each instance of lag, either negative or positive.
Calendars and Progressing the Schedule
- Excessive Calendar Holidays – Contractors and subcontractors should reach agreement on acceptable holidays. The tendency is for organizations to show observance of a diverse set of holidays. The reviewer, however, needs to inspect the calendar for excessive insertion of observed holidays. This may artificially lengthen project duration estimates. If the approved calendar project duration exceeds the scheduler’s execution calendar project duration, the project manager may claim an apparent ahead of schedule completion at the cessation of work. Look for insertion of holidays that, most likely, the work crew will not observe.
- Work Day Estimates – It is important for the reviewer to validate whether duration estimates reflect pure or gross work time. Pure work time estimates are based solely on project related tasks. Gross work time includes project related tasks, non-project related tasks, and non-work related tasks. Duration estimates based on gross work time are more conservative and less optimistic. On the other hand, pure work time estimates may be overly optimistic. Either one or may not represent the true schedule situation. Mixing pure and gross work time is a mistake, so it is important to confirm the subcontractor’s work time estimates, either pure or gross. Refer to the blog Duration Estimates and Pure or Gross Worktime for a more in-depth look at pure verses gross work times.
- Overly Progressing The Schedule – One point to keep in mind is that it is much easier to start a task than to complete a task. Project managers eager to report good news may fall into the practice of overly progressing the schedule by claiming activity commencement progress, particularly, along the longest path. Another temptation is to over progress critical path activities that make up significant portions of the budget. The project manager may even start activities out of sequence to demonstrate project progress that is not representative to the true project situation.
Schedule Validation Summary
An on-time on-budget schedule is quite an achievement, and every good project manager’s target. Unfortunately, even well-intended project managers are susceptible to inadvertently jerry rigging the scheduling tools to portray an optimistic project situation that is not true to reality.
Therefore, inspect the baseline schedule and look for illogical relationships. Confirm that SS or FF dependencies truly exist. Most scheduling guidelines prohibit leads, so any schedule with negative lags is suspect. Positive lags also require review. Try to obtain documentation explaining the purpose for the lead or lag.
Inspect calendar holidays and flag any non-federal holidays for review. Also, confirm the daily schedule, i.e. work hours, of work crew. Does their daily work schedule reflect pure or gross work time? Make sure project documentation specifies the basis of their workday estimates: pure or gross work time.
Finally, inspect in-progress schedules and flag for further review any tasks with minimal progress. These could include 5% of original duration or less, or any tasks commencing out-of-sequence. Yes, the burden of validating a schedule is on the reviewer. However, these simple checks will go a long way in helping reveal the true schedule situation.