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    What-If Analysis

    Definition

    A team brainstorming method that asks what-if questions to find hazards, consequences and safeguards in a process or a change.

    Editorial definition: The QHSE Standard, updated 3 October 2026 · https://qhsetech.com/glossary/what-if-analysis

    What the EPA and OSHA say about what-if analysis

    EPA guidance describes what-if as a group brainstorm: people who know the process put questions about possible deviations or failures. The questions can be framed as what-if, such as what if the pump fails, or as general concerns, such as worry about contamination during unloading. A recorder notes every question, the questions are sorted into areas of investigation, which usually relate to the consequences of concern, and each area is taken up by one or more team members. The team identifies accident scenarios, consequences and existing safeguards, and suggests ways to reduce risk. The method can examine departures from design, construction, modification or operating intent. A what-if analysis usually covers the whole process, from the point where the chemicals are introduced to the end, though it may concentrate on particular consequences of concern.

    EPA, quoting AIChE, calls it powerful when the staff are experienced and warns that without that experience the results are likely to be incomplete. One or two people can do a simple system, and a complex process needs a larger team and longer meetings. The what-if/checklist variant combines the brainstorming with a systematic checklist so each can make up for the weakness of the other; the brainstorming usually comes first, and EPA says AIChE describes it as often the first analysis carried out on a process, followed by more detailed ones. EPA also says a HAZOP needs more resources than the simpler techniques.

    In the United States, 29 CFR 1910.119(e) lists what-if, checklist and what-if/checklist among the acceptable methodologies for a process hazard analysis, next to HAZOP, FMEA, fault tree analysis and an appropriate equivalent. Appendix C says OSHA expects less complex methodologies for the simpler processes of small businesses, and that employer associations might develop a generic analysis from checklist or what-if questions. It also says every methodology has limitations and that assumptions need to be documented. The summary is general information, not legal advice.

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    What a what-if record holds in software

    • The subject: the process, the unit or the proposed change, with the drawings, procedures and revisions the team used.
    • The team members, their experience of the process and who led the session.
    • Each question as asked, including general concerns, with the area of investigation it was placed in.
    • For each question the scenario, its consequence, the existing safeguards and any suggested action.
    • The checklist used, if the what-if/checklist variant was applied, with its version.
    • Whether the review covered the whole process or focused on particular consequences, and why.
    • Assumptions, open points and the questions the team could not answer.
    • Actions with owners and dates, and the later review of whether each was done.

    What-if, checklist, HAZOP and JSA

    A checklist tests a process against a prepared list of standards and practices, while what-if lets the team generate its own questions. A HAZOP uses a fixed set of guide words at each point in the process and, according to EPA, needs more resources. A job safety analysis breaks one task into steps and looks at the hazards of each step, which is a different subject from a review of a whole process or a change.

    A hypothetical example: a change of raw material grade

    The company and the change here are invented and describe no real company. A plant proposes to buy a raw material from a different supplier, in a grade with a different water content. A small team that includes an operator, a process engineer and a maintenance technician meets with the existing procedure and drawings. A recorder logs each question as it is asked, including the general worry that the new delivery might not be recognised at the unloading point.

    Questions are grouped into the areas of unloading, storage and the reaction step. For the reaction step the team asks what if the water content is higher than expected, records a possible side reaction, notes the existing temperature alarm as a safeguard and raises two actions: a goods-in check on water content and a trial under supervision. A checklist for the storage area is then used to cross-check for items the questions missed, which finds that the grade label on the tank has no space for the new grade. Both actions go to owners with dates. The recorder notes that unloading procedures were outside the scope of this session.

    Common misunderstandings about what-if analysis

    • A list of questions is not an analysis. The record needs scenarios, consequences, safeguards and actions, not only the questions.
    • Quality depends on the team. EPA, quoting AIChE, warns that without experienced people the results are likely to be incomplete.
    • It is not automatically sufficient. OSHA requires the method to suit the complexity of the process, so a complex process may need a more detailed technique.
    • It is not restricted to new designs. EPA says the method can examine departures from design, construction, modification or operating intent.
    • Assumptions are part of the result. OSHA Appendix C says assumptions need to be documented and kept for the next analysis.
    • Worries count as questions. EPA says a question can express a general concern, so the record should keep concerns that were not phrased as what if.

    How what-if analysis relates to other glossary terms

    What-if is a lighter technique that sits beside the other hazard analysis methods.

    • HAZOP: applies guide words systematically at each point and needs more resources.
    • PHA: the overall analysis that what-if can carry out for a simpler process.
    • Management of change: a proposed change is a natural subject for what-if questions.
    • JSA: applies similar questions to the steps of a single task.

    Records and evidence that usually exist for a what-if analysis

    • The question list as recorded in the session.
    • The scenarios, consequences, safeguards and suggested actions.
    • The drawings, procedures and change description the team used.
    • The team list and the session dates.
    • The scope statement saying what was and was not covered.
    • The checklist used, if any, and its version.
    • The action log with owners and closure evidence.

    What a software tool needs to capture for what-if analysis

    • Question records that keep the wording as asked and group questions by area of investigation.
    • A structure that turns a question into a scenario with consequence, safeguard and action fields.
    • Version control of the checklist used with the what-if questions.
    • A way to log a general concern as a question without forcing it into a what-if form.
    • A link from a proposed change to the analysis performed on it.
    • Action tracking with owners, dates and closure evidence.
    • A review prompt after changes to the process, with an export for auditors.

    Catalog profiles documenting risk assessment workflows

    These profiles meet the risk assessment rule. The rule does not establish support for question-based sessions or checklists, which a demonstration should cover.

    Same rule for every product: tagged “Risk Assessment” or “Risk Management”, with a sourced risk assessment or risk register capability in its record, or one the vendor stated to us, labelled as vendor-stated. Documented and conditional capabilities qualify; check the linked scope before treating a module as included.

    Tekmon pays for a sponsored placement (above); its place in this list follows the same rule as every entry. How lists are ordered

    All 38 matching profiles are shown. Documentation review, not hands-on testing or a claim of compliance.

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    Frequently asked questions

    Is a what-if analysis enough for a process hazard analysis?

    OSHA lists what-if as an acceptable methodology and requires the choice to suit the complexity of the process. OSHA Appendix C anticipates less complex methods for the simpler processes of small businesses. A complex process may need a more detailed method.

    Who should take part?

    EPA guidance describes a team of experienced people who know the process. One or two people can do a simple system, and a complex process needs a larger team and longer meetings. OSHA still requires a team with engineering and operating expertise for a covered process.

    Can what-if be used for a change?

    EPA guidance says the method can examine departures from design, construction, modification or operating intent, so a proposed change is a suitable subject. Record the change and the questions asked about it.

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