The delta neighborhood

In this chapter, the relative scores, under certain conditions, are measured for the example of eight homogenous airports from the previous chapter. As discussed in the previous chapters, each supposed condition can result different relative scores and ranks for airports. In other words, the relative scores of firms are completely dependent upon the supposed relationship between factors or the supposed weight/worth/price for each factor. The optimization approach is applied while the weights/prices of factors are the same for the airports and one of the conditions such as decreasing the overall input values, increasing overall output values or both decreasing the input values and increasing the output values are assumed. After that, a delta neighborhood of a firm is introduced to find a bridge between the concepts ‘doing the job rights’ and ‘doing the job well’. Mathematical arguments are provided as well as computer programming with detailed illustrations. At the end of this chapter, readers are completely prepared to utilize the performance evaluation of a set of homogenous firms with multiple input factors and multiple output factors.