The elastic generalized assignment problem (eGAP) is a natural extension of the generalized assignment problem (GAP) where the capacities are not fixed but can be adjusted which is expressed by continuous variables. These variables might be un-bounded or restricted by a lower or upper bound,...

The elastic generalized assignment problem (eGAP) is a natural extension of the generalized assignment problem (GAP) where the capacities are not any longer fixed but can be adjusted which is expressed by continuous variables. These variables might be unbounded or restricted by a lower or upper...

A single round robin tournament (SRRT) consists of n teams and a set of periods. Matches between the teams have to be scheduled such that each team plays against each other team exactly once and each team plays at most once per period. In order to establish fairness among teams we consider a...

We introduce a new class of valid inequalities for the maximum round robin tournament (MRRT) problem. They strengthen the linear relaxation and improve the upper bound. We also answer negatively the question of Briskorn if the optimal objective value of the MRRT problem and that of its...

This paper studies the allocation of buffer times in a single machine environment. Buffer times are a common tool to protect the schedule against disruptions such as machine failures. We introduce new classes of robust machine scheduling problems. For an arbitrary scheduling problem 1

This paper studies inventory constraints in a machine scheduling environment. Jobs can add and remove items of different types to the inventory and from the inventory, respectively. Jobs removing items cannot be processed if the required amount of items is not available. We first have a look at...

Single round robin tournaments are a well known class of sports leagues schedules. We consider leagues with a set T of n teams where n is even. Costs are associated to each possible match. Moreover, stadium availability, fixed matches, and regions' capacities are taken into account. The goal is...

The purpose of this paper is to analyze the influence of uncertainty on the value of real options while allowing for a possible change in the value of the underlying asset. We show that the proposition of a strictly positive influence of uncertainty does not hold, if the value of the underlying...