Last month's "Getting it Right" column (September, 2005) acknowledged that there are various levels of testing rigor currently provided by commissioning professionals. When developing their commissioning procurement scope of work, facility owners need to make an effort to specify the level of testing rigor and documentation required. Simply requiring the commissioning professional to "test" systems is risky, because that term is not universally defined or understood.

There is a continuous spectrum of testing preparation, execution, and documentation rigor in practice today. The following table captures a range of approaches taken by commissioning providers. It is safe to say that each commissioning provider's approach is unique and falls somewhere within the bounds of this table.

My definition of a "generic" test procedure is one that is intended to be "one size fits all" for a particular type of system (e.g., constant volume AHU, variable volume AHU, heating hot water system, variable volume reheat terminal unit, laboratory environmental control system). It provides a list of typical control sequences that need to be verified as operating properly without providing details regarding how to do that.

Because each new building system is designed differently, the specifics of how the sequences operate and therefore, the details of how to test those sequences need to be customized in order to more rigorously test the unique new systems. In the accompanying table, the difference between Medium Low and Medium is the customization of the generic test procedures. This customization is simply removing the generic sequences of operation that do not apply to the specific systems being tested, and then adding sequences that may not have been addressed in the standard generic procedures.

The Medium High and High levels of rigor are where the test procedures are customized to include acceptance criteria in the written test protocol. Medium High uses the generic test procedures with equally generic acceptance criteria. The High rigor test procedures are fully customized and documented ahead of time to step-by-step test each mode of operation exactly as defined by the design engineers. The design engineers' specified functional performance is used as the pass/fail acceptance criteria.

The best way to judge a commissioning provider's approach to testing is to request example test procedures and reports and to request a narrative description of their test preparation, execution, and documentation processes. Next month, we'll address the advantages and disadvantages of the various levels of rigor. ES