HAZOP

HAZOP & LOPA Studies for High Hazard Process Plants

Robust design and safe operations start with a clear view of how things can go wrong—and how to stop escalation. Our HAZOP and LOPA services translate process knowledge into practical safeguards and clear design/operational decisions.

HAZOP at a Glance (a Process Hazard Analysis technique)

What it is:
A structured, guide word–driven review of a process to find credible deviations from design intent, their causes and consequences, existing safeguards, and the actions needed to reduce risk.

When it’s used / lifecycle applicability:

• Concept & FEED: scope level hazards, segregation, relief strategy, shutdown philosophy.
• Detailed Design: node by node review against P&IDs, control narratives, causes & effects.
• Pre Startup/Commissioning: verify actions closed; procedures, alarms, interlocks and relief devices ready.
• Operations & Modifications (MOC): re HAZOP focused on changed nodes/units.
• Decommissioning: non routine hazards (inerting, isolation, waste handling).

Merits of HAZOP:

• Systematic, defensible identification of causes/consequences.
• Multidisciplinary sharing of plant knowledge and tacit experience.
• Early capture of design errors and operability issues.
• Direct linkage to safeguards, procedures, alarm set points, proof testing needs, and relief design.
• Creates a prioritized, traceable action list for closure.

What we do (HAZOP):

• Scoping & preparation: node selection, guide word set, data pack (PFDs/P&IDs, control narratives, C&E, relief summaries).
• Expert facilitation & scribing: keep the team efficient and on topic; capture high quality worksheets in real time.
• Risk ranking: consistent consequence categories and likelihood scales; clear basis of judgement.
• Actionable outputs: node worksheets, safeguard adequacy notes, P&ID markups, recommendations with owners/due dates.
• Integration points: flag LOPA candidates, SIF opportunities, alarm rationalization items, and relief/flare checks.

Our competencies (HAZOP):

• Senior facilitators with deep refinery, petrochemical, and upstream/downstream experience.
• Strong control/safeguarding background (BPCS, SIS, FGS, shutdown logic, relief & drainage).
• Efficient digital recording, cause–consequence clarity, and clean audit trails.
• Clear post study follow up: action tracking and verification of closure.

LOPA at a Glance (Layer of Protection Analysis)

What it is:
A semi quantitative method that takes significant HAZOP scenarios and compares their unmitigated risk to your tolerability criteria by crediting only independent, effective layers of protection (IPLs). It identifies the risk gap and the required risk reduction.

Where LOPA integrates with HAZOP:

• HAZOP flags high risk deviations → screen into LOPA.
• LOPA quantifies initiating event frequency and IPL performance (PFD/credit).
• If a risk gap remains, LOPA recommends additional IPLs—often a Safety Instrumented Function (SIF)—and sets the target SIL.

The LOPA “onion” (layers from core hazard outward):

1. Inherent safety / design (eliminate/minimize hazard)
2. Basic controls & interlocks (BPCS)
3. Alarms with operator response
4. Safety Instrumented Functions (SIS/SIFs) – trips, ESDs
5. Mechanical/physical protection – PSVs, rupture discs, dikes, spacing, blast/fireproofing
6. Detection & mitigation – fire & gas detection with automatic deluge/suppression
7. Emergency response – firefighting, isolation, evacuation, community protection

Note: IPL credit depends on independence, functionality, integrity, and auditability per your company standard.

LOPA as the starting point for SIF identification & SIL determination:

• Calculate the required risk reduction factor (RRF) from tolerable vs. current risk.
• Select candidate SIF(s) to close the gap.
• Convert RRF to target SIL (e.g., SIL 1–SIL 3 for most process applications).
• Hand over to the IEC 61511 safety lifecycle: Safety Requirements Specification (SRS) → design → verification → proof test planning → operations & maintenance.

What we do (LOPA):

• Define initiating events, frequencies, consequence categories, and corporate risk criteria.
• Assess IPL independence and performance; apply defensible PFD credits.
• Quantify risk gaps and recommend optimal combinations of IPLs (not “SIS by default”).
• Identify SIFs and set target SILs, then develop or review the SRS and proof testing intervals.
• Provide clear calculations, assumptions, and a management summary for decisions.

Deliverables You Can Expect

• HAZOP plan & agenda, node list, and data pack checklist.
• Facilitated HAZOP worksheets with risk ranking and action register.
• LOPA worksheets with initiating events, IPL credits, risk gaps, and recommendations.
• SIF register with target SILs, draft SRS inputs, and links to C&E, alarm philosophy, and relief summaries.
• Executive report highlighting major hazards, key decisions, and closure priorities.

Ready to scope a HAZOP or convert findings into a defensible LOPA and SIL target?

We’ll tailor the depth and deliverables to your project phase and risk standards.