E.S.M. conducted a Reliability, Availability, and Maintainability (RAM) study, along with supporting safety assessments, for a 7.5 MW stand-by diesel generator system designed by a specialist power systems and equipment supplier.
The system comprised three diesel generators operating in parallel to provide backup power for critical infrastructure as part of a nation-building energy project.
E.S.M.’s RAM study was delivered in two parts:
- A qualitative assessment using a Failure Modes and Effects Analysis (FMEA)
- A quantitative assessment using Reliability Block Diagrams (RBDs)
Qualitative Assessment – FMEA
The FMEA examined each major sub-system, including the multi-generator arrangement, bulk fuel storage and delivery system, air delivery system, master control system, and emissions control system. By analysing potential component-level failures, the study identified how each sub-system could fail to meet its intended function and the consequences for overall system performance.
Quantitative Assessment – RBD Modelling
Insights from the FMEA formed the basis of the quantitative RBD modelling. The RBDs captured system elements with redundancy or stand-by capability, as well as single points of failure. Using a combination of vendor-supplied and industry-standard reliability data, E.S.M. calculated key reliability metrics such as:
- Mean Time Between Failures (MTBF)
- Mean Time To Repair (MTTR)
- Availability (A)
- Probability of Failure on Demand (PFD)
Design Collaboration and Reliability Improvements
Given the system’s critical role, E.S.M. worked closely with the design team to interpret the results and identify practical, achievable reliability improvements. These included targeted spare parts strategies, enhanced maintenance requirements for critical components, and design enhancements to address identified vulnerabilities.
Additional Safety Studies
Beyond the RAM assessment, E.S.M. facilitated Safety in Design and HAZOP workshops. These sessions provided further recommendations to enhance operability, maintainability, and lifecycle safety.
These studies were not just compliance exercises. They delivered meaningful insights that directly informed design decisions – ultimately improving the reliability, availability, operability, and safety of the generator system.
