Group decision-making: Case study ¿ Highway construction

© Springer Nature Switzerland AG 2019. This chapter deals with a very important issue. Group decision-making is where the decisions are not taken by a sole DM but by a group of DMs. This is a normal procedure for large projects where it is essential to have a great level of certitude, most especially in performance values corresponding to qualitative, or even quantitative, criteria. A major problem is of course how to consolidate the different opinions of the DMs on an issue. This quandary is addressed here, considering a new approach that relies on quantitatively measuring for each objective the degree of response for changes made by the group members. That is, each member of the group is free to intervene and make his/her opinion known in the result of one objective or in all of them. His/her observations are incorporated to the model and run again, and results are quantitatively compared with the original and changes made if necessary. At the end of the process, the result reflects opinions and changes of all members of the group. The most important issue is that each change produces a result that can be measured quantitatively; therefore, no subjectivity is present, other than the values proposed by members of the group.