For various classes of vector optimization problems, necessary and sufficient optimality conditions are developed in terms of first order tangent cones and second order tangent sets and cones. Additional remarks are also made.

In a conventional dial-a-ride-system passengers are moved with the same vehicle between their pickup and their drop-off location. In a dial-a-ride-system with transfer, it is possible (or even standard) that passengers change the vehicle once or several times. Transfer Scheduling Constraints...

Sales force management decisions belong to the major issues considered in marketing research. Among others, the alignment of sales territories has been one of the main field of work for years. Recent results have reported a strong impact of the alignment of sales territories on profit, and,...