Presents some of the underlying reasons why commissioning has become necessary and what makes it valuable. Goes on to describe the commissioning process with suggestions on how to prepare for commissioning, how to develop a commissioning plan, who the parties are and what their roles should be. Concludes by presenting some examples from actual commissioning experiences as a means of showing what commissioning can be expected to reveal, what data can be obtained, how to analyse those data, and what corrections were made.KEYWORDS: Commissioning