SISTEMA has been designed to provide developers and testers of safety-related machine controls with comprehensive support in the evaluation of safety in the context of EN ISO 13849-1.

SISTEMA stands for "Safety Integrity Software Tool for the Evaluation of Machine Applications’ and enables users to model the structure of the safety-related control components based upon the designated architectures. This, in turn, allows automated calculation of the reliability values with various levels of detail, including that of the attained Performance Level (PL).

Relevant parameters such as the risk parameters for determining the required Performance Level (PLr), the Category, measures against common-cause failures (CCFs) on multi-channel systems, the average component quality (MTTFd) and the average fault detection level (DCavg) of components and blocks, are entered step by step in forms. Once the required data have been entered into SISTEMA, the results are calculated and displayed instantly.

A practical advantage for the user is that any parameter change is reflected immediately on the user interface with its impact upon the entire system. The time-consuming consultation of tables and calculation of formulae (calculation of the MTTFd by means of the parts count method, symmetrization of the MTTFd for each channel, estimation of the DCavg, calculation of the PFH and PL, etc.), are performed by the software. This enables you to "play" with parameter values and thus to assess the global effect of modifications with a minimum of effort. The final results are printed out in a report.

The site was launched specifically to deal with concerns regarding the recently introduced Machinery Directive and has become an increasingly popular point of reference for anyone wishing to access the latest information on machinery safety. In addition to the free SISTEMA download there are useful links and a wealth of information on products and standards.

SISTEMA software is available for download on www.wielandsafety.net.

electrical industry machine safety news, e-lec.org