ISA TR84.00.04-2 : 2005

1 Introduction
2 Project Definition
  2.1 Conceptual Planning
  2.2 Process Hazards Analysis
3 Simplified Process Description
4 Preliminary Design
5 ISA-84.01-2004 Application
  5.1 Step 1: Hazard & Risk Assessment
  5.2 Step 2: Allocation of Safety Functions
  5.3 Step 3: SIS Safety Requirements Specifications
  5.4 Step 4: SIS Design and Engineering
  5.5 Step 5: SIS Installation, Commissioning, Validation
  5.6 Step 6: SIS Operation and Maintenance
  5.7 Step 7: SIS Modification
  5.8 Step 8: SIS Decommissioning
  5.9 Step 9: SIS Verification
  5.10 Step 10: Management of Functional Safety and SIS
                Functional Safety Assessment

ISA-TR84.00.04-2005 – Part 2, Example Implementation of ANSI/ISA-84.00.01-2004 (IEC 61511 Mod), provides a detailed example implementation of the ANSI/ISA-84.00.01-2004 (IEC 61511 Mod) for safety instrumented systems (SIS) applied to a polymerization process producing polyvinyl chloride (PVC) from vinyl chloride monomer (VCM). This technical report illustrates the full safety lifecycle in ten steps, including hazard and risk assessment using techniques like HAZOP and LOPA, allocation of safety functions with defined safety integrity levels (SILs), development of SIS safety requirements specifications, design and engineering of SIS hardware and software, installation, commissioning, validation, operation, maintenance, modification, decommissioning, verification and functional safety management. It also emphasizes rigorous documentation, testing, diagnostics, human factors, security measures and adherence to industry standards to maintain functional safety and regulatory compliance throughout the system’s lifecycle.


*A spurious trip, also known as a safe failure or false trip, is an unintended shutdown of a safety instrumented system (SIS) that occurs when a safety function is triggered without a genuine process demand. This means the system incorrectly believes there's a problem and initiates a shutdown, even though the process is operating normally.