Recipe for a Complete Process Hazard Analysis – Especially Addressing the Key Demands from US CSB

For your immediate review, please download the latest free resource paper from PII, titled Recipe for a Complete Process Hazard Analysis – Especially Addressing the Key Demands from US CSB, co-written by Revonda Tew, PII Principal Engineer & Instructor, and William G. Bridges, PII President, and being presented today at the 13th Global Congress on [...]

By | 2017-03-27T13:56:29+00:00 March 27th, 2017|CSB, Events, Free Resources, PHA|0 Comments

New Papers in Free Resources on Identifying SIF-SIL as part of PHA/HAZOP, PHA of Non-Normal Operation Modes, and Writing Operating Procedures and Troubleshooting Guides

Just posted in the Free Resources section of the Process Improvement Institute website are three new and invaluable papers related to issues important to process safety management professionals everywhere: Identify SIF and Specify Necessary SIL, and other IPLs, as part of PHA/HAZOP Learn why it is not necessary to “Boldly Go Beyond HAZOP and LOPA.” [...]

By | 2016-12-07T01:33:30+00:00 April 22nd, 2016|HAZOP, PHA, SIF, SIL|0 Comments

Does LOPA really replace 90% of the QRA?

Well, that depends on what you call QRA. Some companies (the folks they have taught) define QRA as only the high level risk assessment that may be performed at the early design phase of a project to make large siting and fire protection (and other mitigation) decisions. LOPA does not replace that specific QRA. But [...]

By | 2016-09-05T05:54:22+00:00 August 26th, 2015|CCPS, HAZOP, LOPA, PHA, QRA|0 Comments

ESTIMATES of ACCIDENT FREQUENCY – Per Scenario and per Site

Do Not believe the math as black and white or as accurate. When we accept a risk of 10-3 per year per facility, we are not necessarily saying we accept 1/10 deaths per year for the facility... we are actually guessing at both factors. 1) The factors we use for LOPA (and for SIF need [...]

By | 2016-09-05T08:47:42+00:00 August 14th, 2015|LOPA, PHA, SIF|0 Comments

Is Consideration of Double-Jeopardy valid in PHA/HAZOP Discussion?

Double-jeopardy (D-J) is NOT an independent protection layer (IPL) failure after an initiating event (IE). All PHA/HAZOP scenarios are of the type of: IE occurs, then IPL 1 fails, then...., leading to Consequences. However, the definition of double jeopardy (D-J) is when two initiating events, which are independent (or we had hoped they were so), [...]

By | 2016-09-05T08:48:48+00:00 August 13th, 2015|Double-Jeopardy, HAZOP, PHA|0 Comments


We use the terms of tool and method interchangeably. Methods/tools include HAZOP of continuous mode, HAZOP of steps for non-continuous modes of operation, What-if, Checklist. The scope and goals establish the Qualitative Hazard Evaluation that you need to accomplish using one or more of these tools/methods. So, a Process Hazard Analysis (PHA) is a specific [...]

By | 2016-12-07T01:33:33+00:00 June 29th, 2015|HAZOP, PHA|0 Comments

Enroll in a Process Safety Course from Process Improvement Institute!

Process Improvement Institute, Inc. (PII) has 15 experts on staff (each with over 25 years of industry experience; including 10 to 35 years of process safety experience) who teach PSM, PHA Leadership, MOC, LOPA, Procedure Writing, and other specific courses on process safety, as well as Human Factors. You can attend publicly available courses or [...]

By | 2016-12-07T01:33:33+00:00 June 15th, 2015|Human Error, OSHA, PHA, PSM|0 Comments

The Benefits of HAZOP

The HAZOP method is pretty good, if done right. IF you apply it to continuous mode correctly using nodes and all applicable deviations, and adding loss of containment deviation for damage mechanisms; and then if you apply it separately to analyze deviations from steps in startup, shutdown, and online maintenance; and IF you have the [...]

By | 2016-12-07T01:33:33+00:00 June 15th, 2015|HAZOP, PHA|0 Comments

Is the Quality of HAZOPs Declining?

We have not seen a drop in quality of the HAZOP (risk reviews) in projects lately. BUT, we saw a dramatic drop about 25 years ago; this occurred when lots of new folks (EPC companies especially) starting saying "Sure, we can provide that HAZOP for you." There was (and still is) little control of competency [...]

By | 2016-12-07T01:33:33+00:00 January 5th, 2015|HAZOP, PHA|0 Comments