Managing SOS, POS and MOS to Minimize Major Incidents

摘要

This paper looks at some of the incidents that have occurred in ammonia plants and the hydrocarbon industry,rnand discusses the breakdowns in the safety management system which caused such incidents. The failures relatedrnto Start-up Override Switch/System, Process Override Switch/System and Maintenance OverridernSwitch/System are essentially systematic failures and hence a robust audit and verification system is necessaryrnto prevent these failures. A brief description of interlock configurations is included. This paper also discussesrnsome of the nuances associated with the interlock configuration, immediate causes including scope creep andrnroot causes of failures, practices currently undertaken in many of plants and new solutions.