چكيده به لاتين
This study addressed the issue of the timing of project construction to coincide with ordering materials, and provide a mathematical model aimed at increasing the profitability of projects, Considering the difference between revenue from sales and cost of logistics costs such as the cost of buying , ordering, shipping and storage, the cost of renewables, the cost of reducing the duration of the project activities in order to achieve time agreed with the customer as well as the cost of doing the project with different quality-looking determine the amount of material required in each period, the renewable resource requirements, time The start of the project, the latest time of completion of project activities, as well as the latest activity in order to achieve the agreed time with the customer, and the timing and number of sales projects to gain access to capital to finance the cost of each period as well as access to construction is more profitable projects.
Because in the real world, levels of interest rates and inflation caused undeniable determine the time value of money and thus determine the amount of material required in each period as well as the timing and number of sales of product to obtain the capital necessary to finance each period as well achieve greater profits are, therefore, in the calculation of income and expenses in the mathematical model to adapt to the real world, the effect of interest rates and inflation are taken into account.
After the linear mathematical model and making it to the model of the software used CPLEX solver with GAMS. Then, using the actual data model was designed, tested, and its results represents. At the end of the study, the number of proposals that can be done in the future to improve the proposed model, are mentioned.
