Systems theoretic process analysis applied to Air Force acquisition technical requirements development

Abstract

The Air Force experienced 12 Class A aviation mishaps in 2016, which resulted in 16 fatalities and 9 destroyed aircraft. So far in 2017, The Air Force has again experienced 12 Class A mishaps with 5 fatalities and 7 destroyed aircraft. (1) In addition to these mishaps, development of new aircraft or modifications to aircraft often take well over the planned duration. Developmental test identifies design deficiencies that must be addressed before the aircraft is fielded, which requires expensive and lengthy redesign cycles. A systems approach to design with humans included as part of the system can improve both the development process and aviation safety. Such an approach was created by Professor Nancy Leveson at MIT and is called Systems Theoretic Process Analysis (STPA). STPA is shown to be applicable to the Air Force acquisitions process throughout the product lifecycle. STPA is also compliant with the airworthiness handbook, MIL-HDBK-516C, and STPA documentation is beneficial to the airworthiness certification inspectors. STPA is applied to two use cases. One is a conceptual JSTARS aircraft, and the other is an unmanned aerial vehicle (UAV) that was modified from a general aviation aircraft. The Air Force is currently in source selection for a replacement to the JSTARS aircraft. The high-level STPA analysis is for a functional replacement to the JSTARS aircraft, as would be needed early in the acquisitions process. Additionally, accidents, hazards, and a safety control structure are developed for the JSTARS support system. The UAV analysis is more detailed, and provides information that is necessary during the Technology Maturation & Risk Reduction phase of an acquisition process.