Various methods of hazard identification are available and regularly used. These include HAZID and HAZOP risk analyses.

HAZID (HAZard Identification) is a risk analysis method used to more generally identify hazards that can impact people, property and the environment. It is strongly recommended that a HAZID risk analysis be conducted as early as possible in a project to allow for project modifications and/or relevant solutions to minimize/eliminate risks as much as possible.

HAZOP (HAZard and OPerability) is a proposed risk analysis method to accurately identify the hazards inherent in a process. It is strongly recommended to carry out a HAZOP when the design of an installation is well done. Indeed, the HAZOP is carried out on the basis of process documents such as P&IDs, functional analyses, operating procedures, etc.

Regardless of the method used, the risk analysis will then determine the relevance of the barriers in place, and the need to implement – or not – new measures.

The 2 risk analysis methods are implemented during participatory work sessions involving engineering, project, operations, HSE, etc. and supervised by an experienced team of facilitators including a chair and a secretary.

When safety barriers are instrumented (SIF), it is necessary to ensure that they provide an adequate risk reduction factor (RRF) for the risks identified in the HAZOP risk analysis.

The SRR is the level of safety integrity (SIL) provided by the barrier, as defined in IEC 61508.

Following the identification and analysis of HAZOP risks, the LOPA (Layer Of Protection Analysis) method may be implemented to quantify the required RRF. The relevance of this method is based on the consideration of all the different layers of protection in place, and on its participatory aspect through a working group similar to the HAZOP risk analysis.

Once the instrumented security barriers (SIF) have been designed, it will then be necessary to validate by calculation that the SIL achieved actually corresponds to the target determined during the LOPA. In accordance with IEC61511, this calculation is based on the reliability data of each component and on systemic modelling via fault shafts.

A reliable installation will not only lead to a high level of performance, but also increase the intrinsic level of safety of an installation.

The AMDEC risk analysis method identifies the possible failure modes of a system, their potential effects and the associated consequences. The criticality of each failure can then be assessed in terms of the probability, severity and detectability of the failure according to IEC 60812.

A RAM (Reliability – Availability – Maintainability) study will be able to quantify these failure modes and assess very precisely the availability of a process; the ultimate objective is to identify and eliminate bottlenecks through the analysis of contributors. A tool such as the PetroGrif© software (Monte-Carlo) proved to be very flexible associated with OREDA© or EXIDA©databases.

Nowadays, P&IDs are increasingly used to integrate fire protection systems directly into a 3D model.