Analysis of the problems that arise in integrating complex systems with human operators is a central issue in the successful implementation of a wide range of systems, ranging from information systems to new items of equipment that must be integrated for use by an individual. The overall process employed by the United Kingdom Ministry of Defence (UK MOD) for military systems is Human Factors Integration (HFI), as described by the HFI Defence Technology Centre (DTC) in the Through Life Capability Management (TLCM) handbook published online in 2009 [1]. An important element is formal Early Human Factors Analysis (EHFA) described in the MOD Acquisition Operating Framework (AOF), which is also available online (2010) [2]. The aim of EHFA is to identify human-related risks at an early stage of project development and determine whether their negative impact and probability of occurrence are high, medium or low. This element of EHFA follows the widely used risk management process for projects, in which programme risks are classified in this way at project outset, recorded in a risk register, and managed as the programme evolves.