Investigating maintenance decisions during initial fielding of rolling stock

Successful organizations align technology with their competitive strategy. The challenge is first to make the right and timely decisions when acquiring new technology. Next, organizations must make decisions that help configure the maintenance services to fit the technology they acquired. Ideally, new technology should fit seamlessly with company practices and ways of working. In practice, this is rarely the case and there is misalignment. For maintenance service providers, the problem of fitting maintenance of new capital assets to traditional ways of working is especially important. This paper examines the decisions made by a maintenance service provider to maximize cost efficiency during initial fielding of rolling stock. We explore the different decisions made to design the support organization around newly acquired trains used for passenger service

Defining line replaceable units

Defective capital assets may be quickly restored to their operational condition by replacing the item that has failed. The item that is replaced is called the Line Replaceable Unit (LRU), and the so-called LRU definition problem is the problem of deciding on which item to replace upon each type of failure: when a replacement action is required in the field, service engineers can either replace the failed item itself or replace a parent assembly that holds the failed item. One option may be fast but expensive, while the other may take longer but against lower cost. We consider a maintenance organization that services a fleet of assets, so that unavailability due to maintenance downtime may be compensated by acquiring additional standby assets. The objective of the LRU-definition problem is to minimize the total cost of item replacement and the investment in additional assets, given a constraint on the availability of the fleet of assets. We link this problem to the literature. We also present two cases to show how the problem is treated in practice. We next model the problem as a mixed integer linear programming formulation, and we use a numerical experiment to illustrate the model, and the potential cost reductions that using such a model may lead to

The deep sea energy park: harvesting hydrothermal energy for seabed exploration

Modern society is in growing need of natural resources. Energy security remains one of the greatest challenges that we face. We need increasing amounts of energy, but it is no longer acceptable to supply it at the expense of the environment. In the coming years we will continue our struggle to innovate and discover new sources of clean, cheap and reliable energy. The ocean has vast resources that could contribute to solving our energy needs.The evolution of the energy market in the coming 50 years requires innovation, strong international cooperation and moderation from consumers. This volume in The LRET collection on seabed exploitation will explore some opportunities of meeting these challenges. The seabed, defined here as the bottom of the ocean, has rich natural reserves including energy, solid minerals, and biogenic resources. Using a scenario planning approach, we determine that energy exploitation from the seabed has the greatest short- and long-term potential.This volume explores the technological challenges in exploiting the seabed as a source of energy. We show two scenarios exploring an evolution-based strategy for maturing technology needed in seabed energy exploitation. The first is a conservative scenario that imagines the business as usual outcome towards greenhouse gas emissions policy. In this outcome, we imagine the growth of energy technology in ocean research, exploration and prospection. The second scenario explores the outcome of an aggressive policy and integration outcome, reflecting the IEA 450 Scenario. In this outcome, the growth of seabed energy technology derives from offshore geothermal or hydrothermal energy.Finally, this volume shows the design of a novel application for power generation from the seabed. The system is an Autonomous Observation Node, designed for ocean research, exploration and prospection. Our novel approach for collecting power from the hydrothermal vent fields implements thermoelectric generators. We show preliminary design options, either tapping a temperature gradient directly from the plumes of a hydrothermal vent, or using high-pressure thermosyphons installed in a well on the hydrothermal mounds. These alternatives can provide clean and reliable power with less environmental impact on the surrounding ecosystem. The system design shown in this volume considers the most conservative scenario of growth for energy in the seabed exploitation industry.We leave the reader with some thoughts. Although the ocean covers approximately 71% of our planet, much of its reserves are yet undiscovered. Any prospect of resource exploitation remains limited by our lack of understanding of the fundamental processes that shape and transform the ocean. Therefore, we need affordable and reliable technology to facilitate long-term scientific observation and exploration of the ocean