Ballast as a part of the railway system plays an important role in the operation of the railways and also has a great impact on repair and maintenance activities. Hence most of the repair and maintenance activities in traditional railway systems are due to the defections in the ballast layer and therefore most of the maintenance budget is spent on repairing these defects. These repair and maint...

the conventional method towards deriving schedule for a fleet of ships to minimize cost alone has the short-coming of not addressing the problem of operation revenue losses associated with delays during maintenance at ships dockyards. in this paper, a preventive maintenance schedule for a fleet of ships that incorporates op-portunity cost is presented. the idea is to assign a penalty cost to al...

The present paper, titled “optimizing the time of preparation, taking into account the timing of   repair and maintenance using non-linear modeling”, has been implemented with the aim of designing and presenting a mathematical model to get the best sequence of operations leading to minimum the total time of production. The main research question is related to the reduction of time and productio...

The National Bridge Stock of Iran consists of about 330,000 bridges, of which around 50% are older than 30 years. Since 2010, Iran Road Maintenance & Transportation Organization has started implementing a comprehensive Bridge Management System in order to manage this aged stock efficiently. To predict future conditions of bridge stock, a heuristic numerical method is presented. This methodology...

This paper investigates the effects of preventive-maintenance cost functions on the optimal preventive-maintenance policy for a leased product with Weibull life-time distribution. During the lease period, any product failures are rectified by minimal repairs and may incur a penalty to the lessor, if the time duration for performing a minimal repair exceeds a pre-specified time limit. To reduce ...