This paper presents a mathematical model for an inventory control system in which customers’ demands and suppliers’ service time are considered as stochastic parameters. The proposed problem is solved through queuing theory for a single item. In this case, transitional probabilities are calculated in steady state. Afterward, the model is extended to the case of multi-item inventory systems. The...

In smart grid paradigm, the consumer demands are random and time-dependent, owning towards stochastic probabilities. The stochastically varying consumer demands have put the policy makers and supplying agencies in a demanding position for optimal generation management. The utility revenue functions are highly dependent on the consumer deterministic stochastic demand models. The sudden drifts in...

We propose a stochastic optimization model for the composition of emergency response teams. An emergency intervention requires first an evaluation of the situation which results in the need of different skills. People involved in the response team must therefore comply with the required skills, be available, with a past and future workload respecting contractual compliance. In addition, we must...

The One-Commodity Pickup-and-Delivery Travelling Salesman Problem (1-PDTSP) is defined on a directed graph as follows. A node of the graph represents a depot and the other nodes represent customers. Every customer has a positive or negative demand of a product. The product is the same for all customers. Customers with positive demand are called pickups and customers with negative demand are cal...

In this paper we introduce a dynamic vehicle routing problem in which there are multiple vehicles and multiple priority classes of service demands. Service demands of each priority class arrive in the environment randomly over time and require a random amount of on-site service that is characteristic of the class. To service a demand, one of the vehicles must travel to the demand location and r...

The ground delay program is a mechanism used to decrease the rate of incoming ights into an airport when it is projected that arrival demand into the airport will exceed capacity. In this paper, we present an integer programming model for planning ground delay programs. The model considers a stochastic capacity pro le which is represented by a set of airport capacity scenarios and their probabi...

This article analyzes the performance of metaheuristics on the vehicle routing problem with stochastic demands (VRPSD). The problem is known to have a computational demanding objective function, which could turn to be infeasible when large instances are considered. Fast approximations of the objective function are therefore appealing because they would allow for an extended exploration of the s...