20.02.08
Condition monitoring and reliability growth
Modern day railway systems and equipment are often required to meet stringent reliability targets and or defined safety requirements. These numeric targets can take the form of availability or reliability figures expressed in units of time or as dimensionless probabilities of failure on demand.
As well as theoretical predictions that these targets will be met, a period of reliability monitoring is necessary to confirm that the theoretical predictions or design and safety requirements have been realised by the in-service operation of the equipment. This also forms part of longer term condition monitoring. The main objectives of reliability demonstration testing are to obtain the in-service reliability data, to ensure that this data is consistent and fit for use, and from the collated data obtain a meaningful measure of the monitored systems or equipment in-service availability.
It is often the case that this data is seemingly obtained via methodical means when in fact it is not. Whenever there are requirements for personnel involved in a fault recording system to make subjective judgments about the nature of faults or to describe what they have observed, they bring with them an element of uncertainty into the data recorded. This has the potential to undermine the subsequent assessments by the data lacking the consistency necessary for accurate analysis of reliability performance.
The solution to the problem is to provide a total fault recording and corrective action system (FRACAS) that is based entirely on pre-defined base information. Coupled with a relational database designed specifically to mirror the format of the initial fault recording to store and automatically analyse the data, a rigorous and consistent means of measuring in-service reliability performance can be achieved.
Transsol Ltd has developed a unique FRACAS that enables in-service reliability and availability performance of monitored systems and equipment to be accurately and consistently determined as part of a reliability demonstration test programme (RDTP).
At the heart of the system is Transsol’s SAbRE database, a management system intended to facilitate reliability demonstration testing (RDT). It is used to store and analyse the test data, calculate system performance and present test results as part of the FRACAS which also includes capture of test data and guidelines for its use.
Initially developed as a standalone run-time application for use on clients’ IT infrastructure, the SAbRE application is now being migrated to the web to offer a managed service accessible to clients via a secure internet connection.
The database enables a wide range of incoming incident reports to be collected, quantified and controlled, such as test and field data and repair and maintenance data, all of which is in pre-coded form so that no subjective judgment need be made as to the nature of a reported incident of fault.
In addition to reliability demonstration, the SAbRE database enables failure modes to be identified and trends analysed. It also provides the information required to optimise maintenance tasks thereby reducing the costs of ownership of equipment. The product is easily tailored to specific equipment, systems and applications. The key functionality of the database includes:
- secure, reliable and auditable record of the testing.
- real time analysis of the test data.
- automatic calculation of system reliability and availability.
- real time monitoring of system RAM performance.
- monitoring of maintenance performance.
- automatic generation of test reports.
- automatic generation of code catalogues.
This system has been successfully deployed on the Athens Metro Lines 2 and 3 Extension Project to measure in-service reliability and availability performance of complex distributed electrical and mechanical plant against contractual numeric targets.
The SAbRE application complements the company’s RaCom database which provides a highly efficient solution to RAMS management activities throughout a project’s lifecycle.
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