shows the standardized maps for eac

shows the standardized maps for each factor together with the standardization approach being adopted. Control point a and control point b in Fig. 6 are the points that govern the shape of the standardization functions. The first control point (a) indicates the value where the membership function starts to increase or to decrease (depending on the nature of the criteria which can be a benefit criterion or a cost criterion, respectively). The second control point (b) indicates the point at which the function reaches membership 1 or 0 depending on the nature of the criteria as explained above.