Preliminary Hazard Analysis

Description

The preliminary hazard analysis (PHA) is a semi-quantitative risk analysis methods that is used to identify potential hazards and the corresponding top events (risks). The PHA sheet identifies as well the required measures and follow-up actions to control the hazard sources. The PHA should consider hazardous components, facilities, safety-related equipment, and environmental constraints.

Effort

Low

Complexity

Medium

Method Type

Semi-Quantitative

ISO 31000

Risk Identification

Risk Analysis - Causes/Threats

Risk Analysis - Consequences

Risk Analysis - Likelihood

Risk Analysis - Severity

Prerequisites

PHA template

Basic Approach

  1. Determining the hazard sources and the corresponding risks.
  2. Extracting all possible causes that could contribute to the top event.
  3. Extracting all possible consequences that could result from the occurrence of the top event.
  4. Determining the probability of occurrence and severity of the corresponding risk.
  5. Determining the required measures for the mitigation and prevention of risks.

Advantages

  • Simple method to apply
  • Overall idea of the possible hazard sources and risks in one picture

Disadvantages

  • It may over-simplify complex situations, particularly where quantification is required

PDF

PHA.pdf