Decision Making and Productivity Measurement
  In this article, the concepts of technical efficiency, efficiency, effectiveness and productivity are illustrated. It is discussed that when firms are not homogenous, the situation is the same as when each factor has a different unit of measurement from one firm to another, and there-fore, no meaningful discrimination can be expressed, unless a set of known weights are introduced to standardize data. A linear programming DEA model is used when a set of known weights are given to calculate the technical efficiency and efficiency of a set of homogenous DMUs with multiple input factors and output factors. A numerical example is also provided. 
Dariush Khezrimotlagh
math.OC