Another way Reason's accident model found application is viaaviation safety as Human Factor Analysis and Classification System(HFACS) developed by Shappell and Wiegmann (2001) for the US AirForce. HFACS consists of taxonomies of unsafe acts, preconditions forunsafe acts, unsafe supervision, and organizational influences, whichcan function as checklists.All of the previous methods have been treated extensively andcompared by Chris Johnson (2003)