Purpose

ANSI/ISA-84.01-1996 has been retired and replaced with ANSI/ISA-84.00.01-2004 Parts 1-3 (IEC 61511 Mod). The new standard is the ANSI/ISA adoption of the international standard, IEC 61511, and includes one additional clause, a grandfather clause covering existing SIS (ANSI/ISA-84.00.01-2004 Part 1 Clause 1.0 y).

This technical report is divided into two parts.

• Part 1 provides guidance on a wide range of topics related to the standard.

• Part 2 provides a single user example to illustrate some of the lifecycle steps in ANSI/ISA- 84.00.01-2004.

ISA-TR84.00.04 Part 1 (ISA-TR84.00.04-1) contains four main clauses.

• Clause 1 is the purpose.

• Clause 2 explains the origins of the new standard and discusses its relationship to other regulations, standards, and practices.

• Clause 3 and Annex A specifically address the grandfather clause and provide guidance on the evaluation of existing SIS.

• Clause 4 provides an overview of the SIS lifecycle and references to subject-specific annexes for additional guidance on key issues.

There is nothing in this guideline that precludes, replaces, or makes obsolete any requirement of ANSI/ISA-84.01-1996 or ANSI/ISA-84.00.01-2004-1. This guideline is a "how to" approach and provides informative, non-mandatory methods.