Process Methodological relationship between RAM and QRA

摘要

During the whole Project Life Cycle of an Oil or Gas plant, Asset and Risk Management are the key drivers for making the project profitable and in the meanwhile compliant with Health Safety and Environmental issues. Risk management aims at controlling risks to protect people, environment and company assets. The objective of Asset management is to decrease as much as possible the downtime caused by unexpected failures optimizing systems and production performance The means by which Asset Management and Risk Management are performed may vary from qualitative tools to quantitative ones Quantitative Risk Analysis is a valuable quantitative tool for the support of Risk management is (QRA) whilst optimizing asset performance may be achieved through Reliability, Availability, Maintainability (RAM) analysis However the control of factors affecting production is not always compatible with safety related aspects, plant personnel safety as well as public safety and above all, most of the time is not easy to find an agreement between RAM figures and QRA results. In light of the above considerations a new approach has been evaluated and is here thus proposed. It involves implementing from the very early stages of a project, a job procedure in which RAM and QRA play vital roles in the decision making. This approach foresees a continuous iterative loop also in synergy with other disciplines, in order to define a cost benefit configuration and a scenario that takes into account risk related issues. The proposed workflow is shown plus two criteria and relevant example of application presented respectively for Concept Selection and Concept Definition phases. In CS phase a decision Matrix scoring and gate screening is proposed: the different options of the project are assembled in a decision matrix with the full set of assessment criteria and a screening process is adopted. All options are tested against five criteria (Safety Availability Operability Cost and Schedule) with the target of requiring good performance in each. In CD phase, an index ISAAC (index for safety Availability and cost) is proposed to assess equipment criticality against the following parameters: - Safety: R_i , IRPA (of a specific category of workers) - Unavailability: Production Unavailability, Costs due to loss of production - Costs: cost of corrective and preventive maintenance - Frequency: Job plan frequency. The index constitutes the basis of producing both global and partial ranking where criticality thresholds are defined via Pareto analysis