H‑Infinity

HAZOP (Hazard and Operability) and LOPA (Layer of Protection Analysis) are structured, systematic techniques for identifying hazards and evaluating the adequacy of existing safeguards. A HAZOP study systematically examines process intent and design intent to identify causes and consequences of deviations. LOPA then quantifies the risk and determines whether additional Protection Safety Layers (SIS) are needed. Together, these studies form the backbone of process safety management.

01What are HAZOP & LOPA?

HAZOP and LOPA are complementary risk assessment techniques:

▸HAZOP — A brainstorming exercise using guide words (NO FLOW, MORE PRESSURE, REVERSE FLOW, etc.) to systematically examine every node in the P&ID and identify potential deviations, causes, consequences, and safeguards.
▸LOPA — A semi-quantitative risk assessment that takes HAZOP findings and evaluates whether existing safeguards provide sufficient risk reduction, or whether additional SIL-rated layers (SIS) are required.
▸SIL Assignment — LOPA results in specific SIL assignments (SIL 1, 2, 3, or 4) for each Safety Instrumented Function based on the risk reduction needed to bring risk to tolerable levels.

02Why HAZOP/LOPA Matter

Proactive hazard identification saves lives and prevents costly incidents:

▸Regulatory Requirement — OSHA 1910.119, EPA RMP, and SEVESO directives require HAZOP/LOPA as part of Process Safety Management.
▸Design Validation — HAZOP identifies design flaws that simulation studies miss — human factors, operability issues, and maintenance access problems.
▸Optimised SIS Design — LOPA prevents over-design (unnecessary SIL 3 where SIL 2 is adequate) and under-design (SIL 2 where SIL 3 is needed), saving capital and operational costs.
▸Insurance & Financing — Many insurers and banks require HAZOP/LOPA before providing coverage or financing for process facilities.

03Our Approach

We facilitate HAZOP/LOPA studies using proven methodology:

1. Study Preparation

Review process documentation (P&IDs, process descriptions, operating procedures), define study boundaries, and select the multidisciplinary team.

2. HAZOP Facilitation

Systematic examination of each P&ID node using guide words. Document all deviations, causes, consequences, safeguards, and recommendations.

3. LOPA Analysis

Quantitative evaluation of risk scenarios, existing保护层 effectiveness, and required risk reduction to determine SIL assignments.

4. Reporting

Deliver comprehensive HAZOP worksheet, LOPA report, SIL assignment register, and tracking spreadsheet for action close-out.

04Scope of Studies

Our HAZOP/LOPA services cover:

▸Greenfield HAZOP — Initial hazard identification during FEED or detailed design phase.
▸Revalidation HAZOP — Periodic revalidation (typically 5-year cycle) or after significant process changes.
▸LOPA for SIL Assessment — Quantitative layer evaluation to determine SIS requirements.
▸Management of Change (MOC) — Hazard review for process modifications, expansions, or debottlenecking projects.

05Standards & Compliance

✓IEC 61882 — HAZOP Methodology

✓IEC 61511 — Functional Safety

✓ISA 84.00.01 — SIS Application

✓CCPS — Guidelines for HAZOP/LOPA

06Why H-Infinity

Our HAZOP facilitators are experienced process safety professionals who have facilitated hundreds of studies across refining, petrochemical, power, and waste-to-energy sectors. We don't just tick boxes — we ask the right questions, challenge assumptions, and identify risks that others miss. Our LOPA analyses are quantitative and defensible, producing SIL assignments that balance safety and cost effectively.

HAZOP & LOPA Studies