RAM study is a methodology utilized for performance forecasting of process facilities given the constraints of equipment design configuration, equipment reliability, equipment maintainability etc. Reliability block diagram is developed to simulate the performance of the facility for the design life cycle. Sensitivity analysis can be performed on the base case results by incorporating a few other options in the design, such as addition of future equipment to the original configuration. RAM analyses are usually applied in the early phase of capital intensive projects to compare alternative designs, maintenance approaches and/or operating strategies.

Quantitative figures are required on the expected level of system performance and on the changes over the system life cycle to equip the analyst with the project decision making process. The nature of a RAM analysis will vary according to the purpose of the study and the scope of work. However, in the majority of cases, the RAM analysis is used to predict system availability and identify ways to improve system availability by considering both equipment failures and maintenance factors. Improved system availability can increase the overall business performance if the additional cost associated with the improvements is lower than the increased revenues. Therefore, the RAM analysis can be used to optimize the production system from a cost/benefit point of view.

• Reliability, typically expressed as the mean time between failures under given operating conditions.
• Maintainability, typically expressed as the mean time needed to return failed or shutdown equipment back to normal service. Influencing factors are working conditions, organization of work, procedures, and resources.
• Availability, typically expressed as the fraction of time the equipment is able to perform its intended function under given operating conditions. Availability is a function of reliability and maintainability.

The reliability is depicted as a probability distribution of the time to failure. When calculating the average availability, the mean value in the probability distribution is used. Likewise, the maintainability is a probability distribution. It is a probability distribution of the time to restore the equipment back to normal service. When calculating the average availability, the mean value in the probability distribution is used. Maintainability includes the expectation that maintenance tasks and their support requirements fall within a pre-defined range.

The Performance Signature – Uncertainty in the Estimated Production Availability

AGT has experienced engineers to perform RAM analysis for onshore and offshore process facilities.