There is a significant interaction between sizing a fleet of rail cars and its utilization. This paper presents a new multi-period mathematical model and a solution procedure to optimize the rail-car fleet size and freight car allocation, wherein car demands, and travel times, are assumed to be deterministic, and unmet demands are backordered. This problem is considered NP-complete. In other wo...

In this paper we present an optimization model for train scheduling. This model constitutes one of the three major components of a solution approach for solving the transit network design problem. The problem of scheduling can be defined in the following general terms. Given the origin destination matrix for the train trips for design period, the underlying train network characterized by the ov...

This study considers a relaxation of the truck and trailer routing problem (TTRP), called the relaxed truck and trailer routing problem (RTTRP). In the TTRP, the number of available vehicles, namely trucks and trailers, is limited. Since there are no fixed costs associated with the trucks or trailers, it is reasonable to relax this fleet size constraint. Besides, most benchmark instances for th...

The fleet assignment problem (FAP) assigns the type of airplane at each flight segment. Since airplane is an expensive resource, poor fleet assignment can cause a great increase in costs of airlines. There are so many consideration which should be tackled in formulation of a FAP problem, especially the parameters regarding to the airplanes. This paper presents a novel, mixed integer programing ...

Reducing cost of material handling has been a big challenge for companies. Flexible manufacturing system employed automated guided vehicles (AGV) to maintain efficiency and flexibility. This paper presents a new non-linear mathematical programming model to group n machines into N loops, to make an efficient configuration for AGV system in Tandem layout. The model minimizes bot...

Flexible automation in the form of mobile robots holds the potential for decreasing operating costs while improving delivery performance in mid-size hospital delivery systems. This paper discusses the use of simulation modeling to analyze the costs, benefits, and performance tradeoffs related to the installation and use of a fleet of mobile robots within mid-size hospital facilities. The result...

Environmental issues and consumer concerns have paved the way for governments to legislate and help usher into operation alternativefueled vehicles and pertinent infrastructures. In the last decade, batterypowered electric vehicles have been introduced and the service industry has followed suit and deployed such trucks in their distribution networks. However, electric vehicles do impose limitat...