Redundancy, Diversity and Dissimilarity

A technical redundancy is the presence of more technical equipment ready for use than is necessary to fulfill the intended function.

Thus, safety devices for the avoidance or control of malfunctions have to be redundant, i.e to be in place in multiple numbers.

In the technical area, a distinction is made between functional and spatial redundancy as well as component and system redundancy.

The principle of redundancy can, of course, also be applied in the organizational/process area and in the area of ​​resource availability.

Diversity is redundancy using systems and system components different in type and mode of operation. A distinction is made between technical diversity and physical diversity.

Redundant systems have a serious weakness, namely failure in the event of a common cause cause, i.e. a common error results in the failure of all redundancies.

This phenomenon can be addressed on the one hand with diversity, on the other hand with the principle of dissimilarity. Dissimilarity means that, e.g., technologies deployed in safety systems must be sufficiently dissimilar/unalike regarding hardware, software, development tools, development teams, manufacturing and testing.

MSE performs analyzes for the identification of vulnerabilities in your safety systems with regard to the characteristics "redundancy", "diversity" and "dissimilarity" and gives recommendations for optimization.

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