The term has two elements:
1. Sum of all measures that are necessary to ensure the safety of the operator as well as the machine against overload. Here the requirements from the responsible authorities have priority; these primarily relate to the safety of controls.
2. Operating safety in the context of trouble-free operation, i.e. far-reaching exclusion of any causes of failure. The measures necessary for this aspect extend down to design details in the individual devices (reliability, availability).