Contractor Selection Using Ordinary, Block & Modified Topsis

Contractor evaluation is a crucial part of the project management cycle and it is related to risk and risk management. One of the most main areas in the construction industry is the bidding process. The low-bid method fails to provide the public interest due to the issue that the lowest offer might not result in the lowest overall cost to the public. This research attempts to solve the contractor selection problem using three versions of Technique of ranking Preferences by Similarity to the Ideal Solution (TOPSIS), and compares their relative performance for two construction contractor's selection problem. The proposed methodological tool can aid the manager in the modeling and selection of suitable contractor according to a set of predefined criteria in order to enhance the long-term performance of projects. Therefore after introducing the theoretical background, two examples are cited to demonstrate and validate the effectiveness and flexibility of these three versions of multi-criteria decision-making (MCDM) approaches. The results showed TOPSIS can be a good choice for contractor selection problems especially when there are a lot of alternatives.