No abstract

The present condition of the construction industry imposes onerous responsibilities on contractors so they are very eager to subcontract some of their works. Subcontractors who directly handle a major portion of all construction activities have a highlighted role in the building industry, so suitable subcontractor selection has a direct effect on the productivity of construction operations. This paper aims to develop a comprehensive model for subcontractor selection based on the fuzzy preference selection index. The improvement of the proposed model lies in the fact that it has found a way to eliminate the weighting criteria phase in selecting the optimal subcontractor where weighting attributes is a challenging task. The consistency test is presented for investigating the accuracy of model results with the previous scientific work.

Projects are the life blood of construction companies. Appropriate project selection is a crucial multicriteria decision that influences the future of such organizations. This paper presents a construction project-selection model that notes the influences of the current projects of a company or what is called the portfolio effect. The model applies a multistage fuzzy multi-attribute decision making (MADM) method to determine whether one should offer or not offer a tender. The final output of the model is the decision to be made about selecting a project for bidding considering three probable policies: (1) diversification, (2) concentration, or (3) neutral policy. The model has been applied in a case study. Practitioners perceived the model as a useful tool for their project-selection decisions. The results of a statistical experiment indicate significant results in accordance with the model’s comprehensiveness, applicability, reliability, and user-friendliness.

Regarding to the high importance of project selection in the project life cycle, solving bid/no-bid problems, especially in the construction industry, is a subject of most recent research. Portfolio selection has been the most interesting area in the last two decades in management research but there is poor investigation in the construction industry. Taking into account the risk, which is inherent in the construction industry and especially in the project selection phase is inevitable. This paper intends to propose a model for project selection and developing two main concepts including company portfolio and risk. The main innovation of this paper is presenting a new framework, which attempts to optimize project selection based on the endurable risk level of a company with regard to the existing portfolio. Considering the user-friendly characteristic of the model, this paper has applied the fuzzy multi criteria decision-making approaches. Finally, the model is implemented in a real case study.

Various challenges such as new technologies, growing complexity and competitive environment, require the main contractor to assign some of the project’s tasks to other parties, the so-called subcontractors. Although subcontract­ing is a usual phenomenon in the construction industry, insufficient attention to the subcontractor selection strategy may pose some major threats to a project. Having in mind the significance of such risks, the optimization of subcontractor selection is essential for the success of the project. The importance of risk management in selecting subcontractors and the direct relation between risks and returns in most projects are two main motives for using the concept of portfolio in this paper. The main objective of this paper is to propose a model to allocate the best portion of project’s task to some subcontractors in order to reach the optimized portfolio of subcontractors and main contractor. This is a new approach in the subcontractor management; therefore, after presenting the model, an illustrative example will be presented for better understanding.