Building commissioning has often been likened to commissioning of a ship, where the Owners thoroughly verify and prove the functional performance of all parts - engines, compasses, sonar, radar, radio, generators, potable water systems, and so on - under all possible conditions and as a condition of acceptance before placing the ship in service, and where the Owner checks the presence of system operating and procedures manuals and the availability of up-to-date navigation charts, and where the crew has been properly and thoroughly trained on the ship's systems' operations and emergency procedures. Commissioning is not new - ships and aircraft have been commissioned for years. Building commissioning has its roots in the Quality Control programs of the 1970s and is a direct product of the Total Quality Management programs of the 1980s. Commissioning is a direct response to building Owners who complain that their facilities do not meet performance expectations, are extraordinarily expensive to operate and maintain, lack valuable documentation, and are staffed by personnel who are unfamiliar with and have never been trained on the building's highly complex operations and control systems. The goals of commissioning include providing a safe and healthy facility; improving energy performance and minimize energy consumption; reducing operating costs; ensuring adequate O&M staff orientation and training; and improving systems documentation. The objectives of this guidebook include providing an introduction to commissioning approaches to a variety of professionals involved with the management, operation, and maintenance of Federal buildings; illustrating case histories, including cautionary lessons learned; providing guidance on commissioning best practices; demonstrating how commissioning can help Federal facility managers meet energy efficiency goals and LEED certification requirements; demonstrating how commissioning can be integrated in facility management and O&M programs to make those programs more efficient and effective; and demonstrating how different types of commissioning (such as retrocommissioning and continuous commissioning) can be incorporated into a variety of building types and applications, above and beyond the most commonly understood commissioning approaches.