Lessons on Achieving Cost Effective ISA 84 SIS Lifecycle Sustainability

Compliance with ISA 84 (IEC 61511) adds significant documentation and testing requirements to already strained budgets and resources. Once the verification documentation and validation procedures are in place, maintaining them through the life of an operating facility presents a significant challenge. This paper presents two distinct case studies of PSM facilities that have struggled through the effort to execute and sustain the ISA 84 Safety Instrumented System (SIS) Lifecycle in a cost effective and efficient manner. The lessons learned will examine the use of standardization methods across an enterprise vs localized practices for execution and closing the loop on the lifecycle, data base automation vs file based documentation, and lagging vs leading key performance indicators presented by different work practices. The lessons presented in this paper will provide investment justification toward a robust program for realizing the functional safety objectives of the ISA 84 SIS Lifecycle.