Availability, Reliability & Maintainability
To maximise the Return on Investment in a complex asset the system or equipment must be ‘available’ to perform its mission when required to do so. Availability may by expressed in a number of ways but is, fundamentally, the relationship between:
- Reliability – the probability that a product will perform its intended mission without failure, assuming that it is operated within intended operating parameters; and
- Maintainability – the probability that a failed item can be restored to a specific state, within a specific time, using a specific set of resources.
Formulating realistic R&M driven requirements and metrics is essential to ensure that an affordable and effective system that satisfies the users’ needs is provided. Utilising commercial and military standards such as Defence Standard 00-40, those requirements insist on total integration with the front-end design process ensuring that R&M engineering has maximum influence on the system design and development and enables key support decisions to be made.
In addition to the definition of AR&M requirements, LSC Group has extensive experience of system Progressive Assurance, which is the methodology required to determine the potential effectiveness of a system, and the application of the relevant techniques to work progressively towards maximising that potential. It also provides an audit trail of activities, both conducted and planned, and the results achieved from those activities. For example, the R&M Case is described in Defence Standard 00-40 as “a reasoned, auditable argument created to support the contention that a defined system satisfies the R&M requirements”. The R&M Case contains all the contractual claims and evidence from design activities, modelling, tests, trials, actual data, etc.
LSC Group specialists employ Progressive Assurance techniques such as:
- AR&M requirements and metric formulation
- R&M Prediction
- Failure Modes, Effects and Criticality Analysis (FMECA)
- Complex R&M Modelling
- Defect Reporting and Corrective Action Systems (DRACAS)
