CPM Schedulers are feared by

 – executives and officers who wouldn’t recognize a critical path from a critical mass

CPM schedulers hate it when decisions resequencing their project timelines are made for us. We argue that CPM is best left to the CPM schedulers. Yet, that does not mean that the scheduler works in a vacuum; calculating estimated sequences and durations without consulting colleagues, and subcontractors and suppliers, yet that is frequently what they do. There are different reasons for this phenomenon.

Preconstruction: those stakeholders savvy enough to retain a scheduler in the planning stage will realize the benefit of having a complete timeline – from D&D (design & development) through CDs (construction drawings. Otherwise, they let budget and other factors unrelated to the schedule dictate what the contract timeline and milestones will be. The winning contractor will own this contract schedule, and his scheduler will have to make his schedule to suit.

“The stakeholders critical path is always money-driven, whereas the CPM scheduler’s is logic-driven.

On the other hand, unless there are design-build elements, or subs are retained early – as they are in negotiated bid contracts, the scheduler may be forced to make his best guess as to sequence and durations. There’s nothing wrong with that, so long as the scheduler understands the importance of verifying and amending the schedule once he is able to speak with the subs.

“CPM Schedulers should be leary of subcontractors who rubber-stamp all their logic and durations: the practice contributes to their future demise, which is what makes it seem counterintuitive.

CPM schedulers will be stonewalled by owner-force and vendors, when they ask them to participate in scheduling their own work, even if it is done as a courtesy. I suppose they feel they are being put upon by being asked to perform an extra service, or think they are doing the scheduler a favor.

I carry placeholder activities in my baseline for owner work until I can get the necessary verification feedback. Should that not be forthcoming, I cut the activities free of the network, and hide them. At some point, I may delete them altogether. As the project progresses, these laggards can access shift-work and week-ends only, so long as they keep clear of the prime contractor’s work. That is the reward for not being a team-player.

“It always helps to have construction field background when estimating schedule durations.

Every subcontract has its start and finish criteria, which is taken from the baseline master schedule, and entered into the subcontract terms. Yet, subs tend not to utilize this schedule as a tool. There are a number of factors for this:

1. Although the schedule includes sequences and durations for the respective subcontractors – durations that they have ratified, they pay surprisingly little attention to dates other than milestones and substantial completion. That’s because they can more or less perform their non-driving, non-critical activities, as they see best fit, and don’t have the same CPM scheduling requirements as the prime contractor.
2. An ill-fated schedule may become obsolete within the first update reporting period. This is an indication of the mettle (or lack of) of the planners, and their implementation of a professional scheduler. This condition is commonplace, and also inspires subcontractors to ignore the schedule, because it is known to be flawed.
3. Contractors don’t always share their schedule updates with their trades; especially if they believe they are handing them ammunition for claims. Rather, they leave them in the dark, or mislead them by issuing more challenging schedules that are meant to motivate their pace.

In the world of CPM scheduling, it often seems like everyone is given a voice but the scheduler, despite his requisite scheduling experience. In many cases, CPM schedulers need to be told what to do – for lack of field experience. Not infrequently CPM schedulers directed to plot timelines that they know are untenable. That is very frustrating to those who like to take ownership of their work.

So the next time the stakeholders rage about a project delay they engendered, and demand answers as to why, tell them:

“I don’t know: I thought you were the expert.”