Call-Backs

The terms reliability, availability, and number of call-backs will be defined in this article; alongside the word definitions, the desired quantitative and qualitative definitions will also be given. A review will be given here of the steps taken to try to define more clearly the criteria by which the maximum number of call-backs allowed per elevator for a year can be determined, and the exceptional cases that are not included in the general accounts are detailed here. I will also review in short the various types of service available and their effect on the reliability, availability, and quality of the elevators.