چكيده به لاتين
Delay in construction projects is one of the main problems occurring between owners and contractors. It may happen for different reasons and several researchers have investigated its root causes. During execution of a project, determining the project's final cost and completion date is important for the parties involved in the project. Deviation from base plans can be found using project control methods, continuous assessment of the schedule, determining progress percentages and earned value parameters. In such circumstances, conflicts might arise between contractor and owner as restoring project's original schedule needs added expenditures by the contractor. Moreover, continuation of the previous procedure and late completion of the project will cause the owner damage. Resolving this issue, the main aim of this research would be providing the solutions for the parties of the projects in the event of the construction delays.
Hence, using game theory in certain and uncertain spaces some models have been presented to describe the behavior of the employer and the contractor in the delayed projects. In the proposed game model for DBB projects, "Game of the Delayed Projects", the payoffs of the parties involved in the implementation of these projects for six possible scenarios were examined in detail. The step-by-step analysis of the model showed that which features could threaten the negotiation, as generally the most desirable scenario. In order to shorten the negotiations, suggestions for the strategies of both sides through Nash and Kalai–Smorodinsky bargaining solution were presented.
Analyzing the model, it can be found that the parameters involved in the problem can affect negotiation in a wider range. The more an owner is capable of bargaining, the negotiation interval will extend toward more compensation time and vice versa. Moreover, it can be stated if the delay fine does not match other parameters of the project; it cannot be effective in the result of the negotiation. However, choosing a proper delay fine can affect the negotiation range so that the owner with no threat and the contractor voluntarily can reach an agreement on compensation of delay with a logical time and cost.
On the other hand, conflict of interest issues are usually multi-dimensional and decision-makers confront multi-criteria decision-making. So, proposing two step-by-step MCDM models in an uncertain context, the problem of the delayed projects has been studied. As a solution, a zero-sum two-person matrix game for DBB projects was presented. Possible alternatives and criteria were defined with grey numbers as the input. In the model, alternatives were ranked in different conditions, using AHP method and Laplace, Horwitz, Bayes and Hodge-Lehmann. Results show that termination is the last alternative that decision makers choose.
In the delayed projects a challenging responsibility of the managers is to devise the most appropriate change while facing a range of uncertainties about the future. While presenting the best change strategy, decision makers usually face a MCDM problem including uncertainty. For this reason, the application of interval values in the face of uncertainties is reasonable. With this approach in the change management model provided for private investment projects facing delays, all input values are grey numbers. Three different novel MCDM models were proposed using SWARA weighting method and the TOPSIS-GM, ARAS-G and Geomean for ranking the change alternatives. Criteria weight and values were interval numbers. in the case study, four alternatives and eight criteria (cost, time and some linguistic variables) were defined. Alternatives were ranked and suggested alternative was implemented practically with positive results.
These models investigate the behavior and strategies of the parties involved in a delayed project through step by step approaches. It helps owners and contractors gain deeper understanding of the given delay problem, get a fairly accurate analysis of their situation and consider possible strategies in facing with such circumstances.
