Historically, fixed fire suppression systems have been designed in accordance with a very specific list of prescribed requirements such as those found in NFPA 13 or other recognized installation codes. While using these prescriptive rules to design fire suppression systems has proven to be successful, this approach does not readily provide for protection schemes that are tailored to the specific purpose and operation of the protected facility. The use of engineering tools to develop fire protection solutions that take into account the unique aspects of a facility or operation in the development of an overall fire protection strategy within the context of a specific performance objective is known as Performance Based Design [PBD]. The practice of PBD requires that any proposed solution provide a level of safety and dependability that is equivalent to that anticipated if the prescriptive solution were followed. However, when PBD is employed these objectives can be achieved in a more flexible manner that may better meet the needs of building owners, Authorities Having Jurisdiction, and Insurers.
Performance Based Design is a major subset of the broader method of allowing flexibility within the design and installation codes known as “equivalency” methods or “alternate methods and materials” (note that NFPA-13 refers to this as “New Technology”)(AMM). Alternate Methods and Materials is a broad category of design options that includes the application of Performance Based Design, but also more restrictive deviations from the prescriptive codes. An example of this is the substitution of listed components that are recognized by the prescriptive code with listed components, which have not yet been incorporated into the code. Many, if not most of the alternate materials and methods that are employed do not take full advantage of the flexibility allowed through the practice of Performance Based Design. Prescriptive codes usually reference “equivalency” or “alternate materials and methods” (AMM) clauses that permit designers to utilize alternative approaches than those specifically recognized by the code. These clauses permit the application of Performance Based Design as a means of rigorously applying engineering principles to provide alternative methods to the “cookbook” approach.