عنوان مقاله [English]
Optimal collaboration of the partners in a project is identified as one of its success factors. Presentation of the theory/the model of the optimal collaboration in the private sector with the public sector in Iran's freeway projects is the main concern of this research. In this study, while trying to scrutinize the concept of collaboration and identify the various dimensions of this phenomenon, the factors contributing to the optimal collaboration and its outcomes will be investigated. To this end, the case study research method is used to collect data and the grounded theory is utilized to analyze data. After analyzing the data, by selecting an appropriate model, the main categories associated with the phenomenon are identified. In this research, private sector investment in BOT projects was considered. Therefore, a critical review of the research literature was carried out at the first step. Then, by referring to a partnership with different actors, different levels of responsibility are
interviewed from both public and private sectors. Then, the data from the speech, the behavior and cooperation of the parties to the partnership are gathered at the meetings of the committee of the investment companies. In the following, the data are analyzed and the theoretical model of collaboration is presented. According to the obtained results of this research, the capability of the private sector, capital security, stakeholder engagement, contract, government managers' competence, risk sharing, and joint decision-making are identified as the factors affecting the optimal collaboration. Besides, the completion of the project with the appropriate cost, time and quality, the achievement of the public sector benefits, the private sector financial profit, the satisfaction of the private sector, and the promotion of the public sector's belief in engagement with the private sector as the result of optimal
collaboration between the parties are identified.