Description: for a proportional element, the quotient of the change in the output variable and the associated input variable; Name: proportional coefficient
Description: proportional element, the quotient of the variation of the output variable to the corresponding variation of the input variable; Name: proportional action coefficient
Description: Probability that an item is in a state to perform as required at a given instant, under given conditions, assuming that the necessary external resources are provided ; Name: Instantaneous availability