Enter, as concisely as possible, the function of the subsystem being analyzed to meet the design intent. Include information regarding the environment in which this subsystem operates (e.g., define environmental conditions, machine performance specification). If the subsystem has more than one function with different potential modes of failure, list all the functions separately.
Start by listing the wants, needs or requirements of the system. Function analysis should be used to insure requirments are defined in terms that can be measured.
Describe the function in terms that can be measured. A description of the function should answer the question: “What is this subsystem supposed to do?” It is helpful to describe the function using a verb-noun phrase. However, avoid the use of verbs like “provide, facilitate, allow,” which are too general.