The Systems Availability Model (SAM) is a program designed to assess the Availability, Reliability and
Maintainability (AR&M) characteristics of multiple systems used over operating scenarios that place varying demands upon those systems, such as that encountered in complex military, commercial shipping, industrial installations and deployed systems of systems. The unique ability of SAM to overlay system dependencies onto complex mission profiles makes it a uniquely powerful and flexible AR&M modelling tool. Mission profiles are built up from a variety of activities, each demanding use of different combinations of equipment, rather than a fixed time at risk approach adopted by many simpler modelling tools. This paper and associated presentation discusses:

• The unique capabilities of SAM and, at a high level, how a SAM model is developed and its crossindustry applications;
• The use of SAM to set system/equipment requirements, and understand the impact of equipment reliability on a fleet of ships undergoing complex operating scenarios;
• Reflecting changes to mission requirements, and the knock-on effect of predicted performance;
• How SAM can be used to understand the significance of individual systems during safety critical activities (e.g. replenishment at sea, close water navigation).