1. ANSI/ISA-84.00.01-2004 Part 1 (IEC 61511-1 Mod), Functional safety: Safety instrumented systems for the process industry sector — Part 1: Framework, definitions, system, hardware and software requirements, 2004.
2. ANSI/ISA-84.00.01-2004 Part 2 (IEC 61511-2 Mod), Functional safety: Safety instrumented systems for the process industry sector — Part 2: Guidelines for the Application of ANSI/ISA—84.00.01—2004 Part 1 (IEC 61511-1 Mod), 2004.
3. ANSI/ISA 84.00.01-2004 Part 3 (IEC 61511-661513 Mod, Functional Safety: Safety instrumented systems for the process industry sector — Part 3: Guidance for the Determination of the required safety integrity levels — Informative, 2004.
4. Guidelines for safe automation of chemical processes;CCPS,1993
5. Layer of protection analysis: Simplified process risk assessment;CCPS,2001