One of the variables we find from project-to-project is the amount of time the commissioning professional is expected to be on site during construction. At first blush, a facility owner would want the commissioning professional to be on site as much as possible, and the only limiting factor would be the cost for the commissioning professional's time and expenses. However, my experience has been that there is a point of diminishing return when being on site "too much" can lead to three possible outcomes.


First, there is a risk of doing the contractors' work for them. Every good commissioning plan will have specific roles and responsibilities for each project team member. Although the contractors' commissioning responsibilities rarely vary from their normally contracted services, the requirement that those responsibilities be performed within the framework of the commissioning process may be perceived as problematic. Timing and documentation requirements may be new, and it is human nature to resist new approaches to old tasks.

One of the commissioning professional's responsibilities is to help coach everyone on the project team. As such, there is a certain amount of assistance inherent to the commissioning professional's role. However, if the commissioning professional is frequently on site to "help" the contractors, there may be a temptation on both sides for the commissioning professional to do the work for the contractors. There comes a time when it just seems easier to do it yourself than to try to train someone else, especially if that someone else is not motivated or interested in learning.

This situation is influenced by the second risk factor: the potential for the commissioning professional to become too friendly with the contractors. If the commissioning professional and the contractors spend a lot of time together on site outside of formal commissioning-related activities (meetings, tests, reviews, etc.), they will want to get along on a personal level and may become friends.

This is a tricky situation, because we want the commissioning professional and the contractors to become professional colleagues, develop strong mutual respect, and work towards the common goal of proper system performance. However, we prefer them not to be such good buddies that the commissioning professional doesn't want to upset the contractor by enforcing the requirements of the commissioning plan. Although this conflict of interest situation could develop in any project, its potential increases at least linearly with the amount of time the commissioning professional spends on site with the contractors.


The third concern with being on site very frequently or constantly is the temptation on the contractors' part to take a casual approach to scheduling commissioning activities. One the most important aspects of an efficient commissioning process is early and diligent scheduling of activities. When the commissioning professional is only on site at relatively wide intervals, the importance of being ready for whatever the commissioning professional needs to do (witnessing equipment startups, balancing, functional performance tests, etc.) is obvious to everyone on the team. Not being ready for that activity means it can not be completed until the commissioning professional returns (schedule impact) or someone is going to have to pay for an unscheduled visit by the commissioning professional (budget impact). Neither of these scenarios is desirable, so the contractors are motivated to be ready when scheduled.

When the commissioning professional is on site frequently, the impact of aborted commissioning activities is not perceived to be that significant. "The commissioning professional will be here tomorrow; we'll try again then." However, the amount of time the commissioning professional spends on the project (and, thus, the fee charged to the owner) increases with each aborted activity. There is the obvious time required to participate in the start and stop of the activity, but there is also the time involved in documenting that it was aborted and rescheduling it.

So, how much is "too much" for the commissioning professional to be on site during construction? As with so many things associated with the commissioning process, "It depends." It depends on the total duration of construction, construction phasing, project delivery method, scope of commissioning, and the delegation of commissioning responsibilities.

I'm not saying that commissioning can't be a full-time job during the construction phase of a project, because in some cases it can be. I am saying, however, that one should avoid having the commissioning professional work on site full time side-by-side with the installation contractors.

It is important that the commissioning professional not be seen as "just another contractor," but as somehow set apart from the installation contractors. Physically separating them is one step in accomplishing this.