The question of Commissioning (Cx) versus Construction Contract Administration (CA) is confused by many. Cx is a process that measures that the owner’s project requirements are fulfilled and CA, at its heart, measures if the Contract Documents have been fulfilled. As Bob correctly points out, CA includes more than just that, but brushing away the chaff, that is the essential difference. CA occurs whether or not Cx is performed. There really is only one type Cx, contrary to Bob’s notion; Bob was describing varying scopes of the Cx work, which varies from project to project from whole building to one or more systems.
Design professionals prescribe a design solution much like doctors prescribe medicine to cure an illness. A/Es use drawings and specs; doctors use an Rx note pad. Contactors are obligated by the contract documents to build; Pharmacists are obligated to fill prescriptions as directed on the Rx note. If the doctor misdiagnosis the illness, the pharmacist cannot be blamed (if he/she fill the prescription correctly) when the patient is not cured; likewise, if the pharmacist doesn’t correctly fill the prescription, the doctor cannot be blamed if the patient is not cured. The same is true of design and construction; the owner is the patient. If the A/E misunderstands the owner’s requirements, the contractor cannot be blamed (if the Contract Documents were correctly followed) when the building doesn’t satisfy the owner’s requirements. In both cases, the courts are all too often the Commissioning authority for the medical industry and the construction industry.
The Cx process as defined in the ASHRAE Guidelines adds a new player in the construction process and a new set of documents that are not present when Cx is not included. The new documents are the “Owner’s Project Requirements” (OPR), and the “Basis of Design Documents” (BoD). These are similar to the old “Owner’s Program” and “Project Brief.” The OPR details the criteria for design and construction. The BoD is the A/E’s statement of their design solution (often in the form of sketches, models, and documents similar to preliminary project descriptions) all which are developed much earlier that outline specifications. The Commissioning Authority (CxA) is the new entity and (if you follow the ASHRAE guidelines) should be involved from the time the A/E is selected (or even before) and continue through Owner Occupancy.
The CxA verifies fulfillment of the OPR at every phase of project delivery from pre-design through owner occupancy. The CxA reviews BoD, Contract Documents, submittals, witnesses construction, specify testing requirements, and witnesses Cx testing. The OPR is used as a filter through which to evaluate design changes, proposed changes during construction, proposed substitutions for products, and more.
I often hear Brian’s question posed as “What is the difference between Cx testing and Field Quality Control (FQC) testing”? The question is not easy to answer, but often is stated as follows: FQC measures that the correct products are properly installed; while Cx testing (only a small part of the whole Cx process) measures whether the resulting construction is achieving the results prescribed in the OPR.
A simple example for MEP applications is as follows: FQC for a piping system will include tests to determine if the system is installed with leak-free joints. The piping specification prescribed the types of pipe and fitting materials and joining methods; and CA verifies that those materials and methods were used and witnesses test that verifies there are no leaking joints. An example for a Cx test may include a verification that all the proper events occurred when a fire alarm occurs (some fans start, some fans stop, some doors remain open and some doors close, elevators go to a selected floor, the fire alarm sounds, and on and on). These tests are most often testing system interfaces and sequence of operations (easily identified for MEP, but not so for static building systems and assemblies). However, there is a clear definition for building-envelop commissioning in NIBS Guideline 3.