Agile methods for project management are often treated as methods for mitigating risk. However, there is disagreement as to whether explicit methods of risk management should be used in projects which are executed according to Agile methodology or is the implicit risk management built into Agile...

The Generalized Transportation Problem (GTP) allows us to model situations where the amount of goods leaving the supply points is not equal to the amount delivered to the destina-tions (this is the case e.g. when fragile or perishable goods are transported or complaints may occur). In this...

A model of a transportation system is expected to be useful in simulations of a real system to solve given transportation tasks. A connection graph is routinely used to describe a transportation system. Vertices can be train stations, bus stops, airports etc. The edges show direct connections...

The purpose of this paper is to present the project portfolio scheduling problem as a multiple criteria decision making problem. A three step procedure to solve this problem will be presented in this paper. In the first step, the problem will be described by a multiple criteria mathematical...

We consider two single-item, deterministic, continuous, finite horizon inventory models having no shortage. A demand rate function, which is relatively general, for the item is assumed. In the first model, units of the item do not deteriorate; while in the second units deteriorate in a constant...

This article discusses the environmental effects of transport, with a particular focus on the natural environment. The authors present methods used for assessing the influence of investments in transport infrastructure on the environment, as well as the concept of a simulation model, which...

During the last couple of years, there has been a tendency to include more and more political goals into public procurements, such as environmental and societal considerations. This can result in higher prices paid by the public sector compared with similar procurements in the private sector....

This paper presents a multi-criteria model for determining the order size for materials used in production. It is assumed in this model that the consumption rate of each material is a random variable with a known probability distribution. Using such a model, in which the purchase cost of...

Game theoreticians usually deal with standard voting methods, such as plurality voting or approval voting. In reality however, some complicated non-standard voting methods are used. In this paper we shall present the voting method and rotation scheme used by the Governing Council of the European...

The most common measure of inequality used in scientific research is the Gini index. In 2007 Zenga proposed a new index of inequality that has all the appropriate properties of an measure of equality. In this paper we want to compare the Gini and Zenga indexes, calculating these quantities for a...