راهبرد بهينه‌ي كارفرما و پيمانكار در پروژه‌ي مواجه با تاخير، با رويكرد نظريه‌ي بازي‌ها

Optimal Strategies Applied by Contractors and Employers for Delayed Projects: Game Theory Approach

از آنجا كه تاخير در پروژه‌هاي عمراني يكي از معضلات مهم و چالش ‌برانگيز بين كارفرما و پيمانكار است، معمولاً به كمك روش‌هاي كنترل پروژه و بررسي مداوم برنامه‌ي زمان‌بندي، انحراف از برنامه‌ي زمان‌بندي و تاريخ اتمام پروژه مشخص مي‌شود. به دليل اينكه برگرداندن پروژه به زمان‌بندي اوليه‌ي پيمانكار، مستلزم صرف هزينه‌هاي زياد خواهد شد و از طرفي ادامه‌ي روند قبلي و تكميل ديرهنگام پروژه، باعث خسارت‌‌ديدن كارفرما خواهد شد؛ در مواجهه با تاخير، تعارضي بين منافع كارفرما و پيمانكار به‌وجود خواهد آمد. از آنجا كه تاكنون براي حل و فصل اين نوع مناضعات، راه حلي مشخص در قالب يك چهارچوب معين براي هر پروژه ارايه نشده است، براي رفع اين مشكل در اين نوشتار با رويكردي كتابخانه‌يي- ميداني و از طريق گردآوري داده‌هايي از اسناد و مدارك موجود با استفاده از نظريه‌ي بازي‌ها، براي توصيف رفتار كارفرما و پيمانكار در پروژه‌‌يي كه با تاخير مواجه شده است، مدلي ارايه شده است. براي ارايه‌ي اين مدل از نظريه‌ي بازي‌ها استفاده شده است، و از طريق چانه‌زني به روش‌هاي نش و كالايي– اسموردينسكي راهكارهايي ارايه شده است. در انتها، ضمن حل يك مطالعه‌ي موردي استراتژي‌هاي ممكن جهت كارفرمايان و پيمانكاران و دستاوردهاي هر كدام در اين بازي آورده شده است.

Delay in construction projects is a major and challenging problem occurring between owners and contractors. It may happen for different reasons and several researchers have investigated its influencing factors. Determining a projectʹs final cost and its completion date is important for all parties involved in project execution. Using project control methods, including continuous assessment of the schedule, determining progress percentages and using the earned value method, deviations from schedule can be found. In such circumstances, conflicts might arise between contractor and owner, as restoring the original schedule of a project requires double expenditure by the contractor. Also, continuation of the previous procedure and late completion of the project will cause damage to the owner. In this research, and by using game theory, a mathematical model has been presented. Through bargaining and by a step by step approach, the behavior and strategies of the parties involved in the delayed project have been investigated. This model helps owners and contractors gain a deeper understanding of the given delay problem, obtain a fairly accurate analysis of their situation and consider possible strategies when they confront such circumstances. In a given case study, points upon which both parties can agree rationally have been proposed. With model analysis, it can be found that parameters involved in the problem can be effective in changing the range width of negotiations. In special cases, such as a disproportionate delay penalty, these parameters even make the negotiations neutral. Step by step analysis of the model showed which features can threaten negotiation, and, according to these analyses, suggestions for strategies of both sides are presented. The proposed model can help the parties reach a rational and realistic decision about the completion date of the project without wasting time. Some assumptions regarding the model have been included, which are possible for others to extend.