Risk-based Inspection: A Methodology for Optimizing Efficiency
By TOM NOLAN, ABS GROUP VICE PRESIDENT, MARINE AND OFFSHORE; and Gareth Burton, ABS Group Senior Director, Offshore Asset Integrity Management
Understanding how to effectively manage ever evolving risks is critical to safer, more efficient offshore operations. To maintain higher specification assets so they can perform at optimal levels, a risk-based inspection (RBI) program can benefit your overall approach to asset integrity management (AIM).
RBI is a risk assessment and management process that focuses on failure modes initiated by material deterioration and controlled primarily through equipment and structure inspection. The methodology combines risk assessment and risk management techniques with inspection activities, such as planning, inspecting, documentation and data analysis, to develop inspection plans that direct inspections toward the areas of highest risk. RBI can be applied to all types of material deterioration processes that may cause loss of integrity for pressure retaining equipment and structures.
Not all standard inspection programs are equally effective in detecting degradation mechanisms and reducing risks. As an alternative, RBI provides the tools and processes to determine the optimum combination of inspection methods and frequencies.
Focusing on Risk Factors
With more attention directed toward the RBI process from regulators as well as industry, there is a greater need to understand how to identify and manage risk factors within complex offshore assets. Benchmarking priorities for safety and reliability during the inspection process has also changed based on complex design specifications, capabilities and advancing technologies.
Coupled with regulatory standards that require verification of safety management systems on offshore assets, today's operators must continuously work to improve the reliability and efficiency of their assets and operations. Inspection, therefore, should be a proactive, strategic planning process focused on the risk factors that impact safety, reliability and integrity, as well as performance and profitability, onboard mobile offshore units and production facilities.
Managing Asset/Mechanical Integrity
Our experience has proven that adopting a systematic, risk-based approach when inspecting machinery, equipment and control systems allows for more effective management of the diverse risks encountered offshore. One of the main drivers is the need for (and in some cases requirement of) an AIM program to confirm and maintain the structural, mechanical and intended functionality of an asset throughout its expected service life.
Our Mechanical Integrity experts have contributed to industry committees addressing these process safety issues, including for the American Petroleum Institute, American Society of Mechanical Engineers, National Fire Protection Association, Center for Chemical Process Safety (CCPS) and International Institute of Ammonia Refrigeration. ABS Group coauthored the CCPS' Guidelines for Mechanical Integrity Systems (Wiley, 2006), which are standards followed by industry to assess and manage asset/mechanical integrity.
An Alternative Approach
As an alternative to traditional prescriptive and time-based programs, RBI relies on a predictive – and preventative – maintenance strategy. The goal is greater attention to detail and procedures that work toward continuous improvement of high-performance assets and high-utilization equipment through careful and risk-informed planning. Our approach involves assessing the risk factors, benchmarking the appropriate RBI methodology and implementing a data-driven assessment program that tracks progress and return on investment.
The basic elements in the development of an RBI program integrate well with our AIM solution, through which we take a holistic view of managing asset integrity. These elements include:
- Determination of the risk introduced by the potential failures of each component
- Identification of the degradation mechanisms that can lead to component failures
- Selection of effective inspection techniques to detect the progression of degradation mechanisms
- Development of an optimized inspection program using the knowledge gained from the first three items
- Analysis of data obtained from the inspections and any changes to the installation in order to feed back into the RBI plan
Balancing Safety and Efficiency
When considered altogether, RBI approaches allow asset owners to optimize their inspection process, balancing inspection activity and resources with the actual risks present on the asset. This allows efficiencies in the planning, inspection and repair process to be realized, helping to reduce downtime and achieve more "focused" operating expenses while contributing to better industry practices.