Apdex

Apdex (Application Performance Index) is an open standard developed by an alliance of companies for measuring performance of software applications in computing. Its purpose is to convert measurements into insights about user satisfaction, by specifying a uniform way to analyze and report on the degree to which measured performance meets user expectations. It is based on counts of "satisfied", "tolerating", and "frustrated" users, given a maximum satisfactory response time tof , a maximum tolerable response time of 4t, and where users are assumed to be frustrated above 4t. The score is equivalent to a weighted average of these user counts with weights 1, 0.5, and 0, respectively.