Why Do I Need Commissioning?

The Answer

We need commissioning to verify that owners recieve facilities and systems that meet their requirements. Period.
Per ASHRAE Guideline 0: “The Commissioning Process is a quality-oriented process for achieving, verifying, and documenting that the performance of facilities, systems, and assemblies meets defined objectives and criteria
Anyone who tells you that commissioning is necessary due to the current quality of engineering design or construction installation is not being truthful and using fear to sell you their services.  These people are not true commissioning agents and should be avoided entirely.  They will continue to use fear throughout the process in order to justify their existence on the project and as a means to expand their scope unnecessarily.

Real Question

Usually, when someone asks the question "Why do we need commissioning?" what they are really asking is "Why do I need 3rd party commissioning?".  In theory, commissioning by a 3rd party is not required as the engineer of record is both responsible and liable for ensuring owner's requirements are met in design, construction and turnover of the facility.
The justification for 3rd party commissioning is to avoid the perception of a conflict of interest.  For example, when a problem arises during construction, there may be a percieved conflict of interest when, through his analysis, the engineer must determine if it is the result of his design or the installation/ construction.  Owner's may prefer a 3rd party to identify the issues and then make an unbiased determination of the cause.  This determination will need to be based on the commissioning agent's engineering analysis in order to validate (or invalidate) the design. As such, the ability to do engineering analysis requires the commissioning process to have a licensed engineer in responsible charge.

Isn't the Engineer Already Doing This

Often times, the question of 3rd party commissioning also includes a question of whether or not the engineer of record is already doing the same tasks as commissioning.  The short answer is yes, in each engineering project, the engineer is doing the basic steps of commissioning.  This is the reason the definitions of engineering found in state statutes include tasks from design through construction.
First and foremost, the engineer of record is responsible to ensure the facility meets the owner's project requirements from design, construction and at turnover even if there is a 3rd party commissioning agent.  Call it basic customer service or a legal requirement based on liability, the engineer is responsible.  Rest assured, if a facility does not meet the owner's requirements, the engineer of record will be sued and held accountable with the state board of engineers.  This fact is an owner's risk management benefit built into state licensure and missing from unlicensed technician type commissioning agents.
The extent to which the engineer verifies the owner's requirements is unfortunately a function of money.  Owner's are not always willing to pay the amount of money required for an engineer to spend sufficient time in the field verifying construction but this does not limit the engineer's liability.  If a facility fails, for whatever reason, the engineer will not be successful in avoiding legal action by simply saying the owner did not pay him enough money.
Again, to be clear, the excuse of insufficient fees does not let the engineer off the hook from verifying the design and its subsequent construction meet the owner's requirements.  In scoping the project, the engineer has to gauge the level of risk he is willing to accept by limiting his own commissioning activities.  The owner must also make the same decision but he has the benefit of knowing the burden of liability is still on the engineer. 
Unfortunately the current fee structure for residential, commercial, and government projects does not usually allow for sufficient engineering oversight during construction.   As such, there is a misconception that commissioning has come about as a sort of quality control service resulting from an increase in failed facilities being turned over to owners in recent years.
Posted by David G. Venters, PE, CPMP
Performance Engineering Group, Inc.