Gym Membership: an Application of theWeibull Distribution

The Swedish physicist, Waloddi Weibull, is renowned for formulating a family of probability distributions for modelling the variability of nonnegative, quantitative, random phenomena (see reference 3). The distribution was originally designed to model the breaking strength of steel (Weibull was scientific advisor to Bofors, the Swedish steel company) but, since then, Weibull analysis has evolved to provide a concise, but flexible, framework for describing and interpreting survival-type data. Indeed, it has been extensively applied in various disciplines ranging from engineering (see reference 1) to ecology (see reference 2) despite Weibull’s own modest understatement that ‘... itmay sometimes render good service.’ The illustrative example in this article is a business application.