CWA-RBIM risk- and reliability-based maintenance method

This article, aimed at readers with a basic knowledge of risk control and maintenance methods, presents the CWA-RCBIM risk- and reliability-based maintenance method developed in 2001 as part of the European RIMAP (Risk-Based Inspection and Maintenance Procedures for European Industry) project. It is the subject of the draft European prEN 16991 standard in 2016 (Risk-Based Inspection Framework: RBIF).

The first section presents the origins of the approach, which stems from the European community's desire to have a methodological framework for establishing risk-based inspection and maintenance programs that take into account the various European and international standards, while distancing itself from American standards such as those of the API (American Petroleum Institute).

One of the aims of this method is to make industrial plant inspection and maintenance programs more cost-effective, while maintaining or improving the safety, health of personnel, the environment and the economic performance of assets. This method is aimed at managers and engineers wishing to implement an RBIM program in industrial sectors (petrochemicals, chemicals, energy production and associated companies).

The second section presents the six essential steps for developing an RBIM risk-based inspection and maintenance program. These steps include preliminary analysis and planning, data research, data collection and validation, multi-level risk analysis, decision making and action plans, implementation and feedback, and performance analysis to develop the rolling program.

To illustrate the content of a RBIM study, the case of an ammonia production plant tank is presented in the third section only in terms of risk-based inspection techniques. The inspection program is developed further, with detailed supporting documentation.

The fourth section provides a comparative assessment of the advantages and disadvantages of RBIM. It concludes with recommendations for the implementation of RBIM and prospects for improvements within the framework of the definitive EN 16991 standard.