Claims between the contractor and the owner are one of the main problems that can occure in construction projects. The number of claims and their overhad cost in construction projects is increasing every day. Therefore, this research aim to design solutions in order to reduce the losses arising from cost claims in Design Bid Build projects. These solutions are classified in two classes: 1. designing a model for determining suitable price of bid for preventing cost claims, 2. designing an approach for determining the suitable decisions to resolute cost claims. Therefore, a hybrid mathematical programming and statistical approach was presented for determining the suitable price for biddings in DBB construction projects. In order to do so, the first step was to assume the uncertain parameters.