A multi item inventory model with demand dependent on unit price and leading time with limited storage space and set up cost is considered in this paper. The varying production and leading time crashing costs are considered to be continuous functions of unit price and leading time respectively. The model is solved using Karush Kuhn Tucker conditions approach with optimal order quantity, unit pr...

In this study, a contract for vertical and horizontal coordination is developed in which transportation mode and carbon emissions tax play a key role in determining the values of the contract parameters. The contract is designed for simultaneous coordination of cooperative advertising and periodic review replenishment decisions of a supplier and two competitive retailers. To obtain the optimal ...

In this paper we study the job shop scheduling problem under the assumption that the jobs have controllable processing times. The fact that the jobs have controllable processing times means that it is possible to reduce the processing time of the jobs by paying a certain cost. We consider two models of controllable processing times: continuous and discrete. For both models we present polynomial...

In this research, a coordination mechanism based on a credit period in a two echelon supply chain with one buyer and one supplier, is designed. The buyer is faced with uncertain demand by coping with normal distribution. Both lead time and ordering cost for receiving his order can be reduced at an added cost; in other words, they are controllable. The optimization models with and without integr...

Time-cost trade off problem (TCTP), known in the literature as project crashing problem (PCP) and project speeding up problem (PSP) is a part of project management in planning phase. In this problem, determining the optimal levels of activity durations and activity costs which satisfy the project goal(s), leads to a balance between the project completion time and the project total cost. A large...