Reliability engineering

For years TECSA S.r.l. activities in the field of risk analysis have been flanked by RAMS type studies for the investigation of aspects strictly connected with the systems under analysis but not limited to safety aspects (Safety). The conduct of RAMS (Reliability, Availability, Maintainability and Safety) type studies on systems, as well as sub-systems, modules, equipment, has numerous purposes, among which:

  • set a target value for the availability of a system;
  • reveal and correct aspects of the design involving an unacceptable risk to safety, the environment, exposure to operational economic damage and non-operational economic damage (within the acceptability defined in the business continuity study);
  • Predict the ability of a system to achieve an objective value of availability in a given time;
  • evaluate the level of performance of an already operational system in terms of availability;
  • support evaluations of technical-economic opportunities related to alternative process and design solutions (not exclusively redundancies of components and systems), supplies, operating methods, maintenance methods, spare parts, based on the different impact on the availability of a given system.


Availability is defined as the probability of a system to be functional at a given time. Therefore, availability is a function of the number of faults occurring in the system in the given time and the time required to return the system to its functional state after each fault. The reliability of a system is the probability that the system will remain functional for a given time. The maintainability of the system is a function of the time required to restore a failed system to functionality. The availability of the system is therefore a function of both reliability and maintainability.

As regards specialist support activities in the field of maintenance, TECSA S.r.l. has drawn up guidelines for many clients for the compilation of work permits, procedures for the management of work permits (within the SGS for the Prevention of Major Accidents) and has prepared the appropriate forms. This is also to meet any specific requirements deriving from related regulatory requirements (e.g. management of interventions in confined spaces, management of maintenance activities of critical elements and systems such as fire-fighting equipment, etc.).

It should be noted that the activities of in-depth analysis on the subject of verification of availability and reliability are supported by simulation, a field in which TECSA S.r.l. has strongly specialised over the years, with particular reference to studies carried out with the FMEA/FMECA/FMEDA, FTA, RBD methodologies also through the use of advanced calculation tools.