States commissioning is a systematic, documented and collaborative process that includes inspection, testing and training conducted to confirm that a building and its component systems are capable of being operated and maintained in conformity with the design intent. Argues that the goal of commissioning is to ensure that the actual performance of the building meets or exceeds the intent of the design and the expectations of the occupants. States the Design Intent document (DI) is a detailed explanation and documentation of the ideas, concepts and criteria that define correct building operation, and is the weak link in the commissioning process. Examines the process to show what the DI is, and must be, if the commissioning process is to be a success. Discusses the DI methodology and notes how the DI protects the designer. Deals with specific inclusions and some exceptions. Lists the items that should be included in the DI. Concludes that in general the DI is considered complete if it answers the question "What does the building do?"