This thesis develops integer linear programming models for and studies the complexity of problems in the areas of maintenance optimization and location–routing. We study how well the polyhedra defined by the linear programming relaxation of the models approximate the convex hull of the integer feasible solutions. Four of the papers consider a series of maintenance decision problems whereas the ...

In broad terms, maintenance optimization models includes the mathematical models focused on finding either the optimal balance between costs and benefits of maintenance or the most appropriate time to execute maintenance. Parameters often considered in this optimization are the cost of failure, the cost per time unit of downtime, the cost (per time unit) of corrective and preventive maintenance...

conclusions although propofol remains a standard agent for such types of surgeries, lidocaine proved equally effective and coupled with its low cost, minimal side effects and omission of other hypnotic agents was a plausible induction agent and a maintenance drug in the selected cases. case presentation lidocaine was applied as the sole anaesthetic for induction and maintenance during aneurysm ...

Surveys found that large contractors replace approximately 10% of their equipment fleet units annually in North America. Cost minimization model is a commonly accepted method for equipment replacement which helps to identify these equipment units whose total owning and operating cost reaches their minimum point as candidates for replacement. While the model is conceptually clear with the aim of...

neonatal purpura fulminans is a rare and life threatening disease that can be inherited or acquired in etiology. it manifests as dic and extensive subcutaneous thrombosis. the condition is often fatal unless there is prompt diagnosis, and judicious therapy. the most important causes of this condition are infections and congenital deficiency of anticoagulant proteins c and s.in the case of pc (p...

General preventive maintenance model for the components of a system, which improves the reliability to ‘as good as new,’ was used to optimize the maintenance cost. The cost function of a maintenance policy was minimized under given availability constraint. On the other hand, in order to ensure appropriate reliability and availability, the development of the optimal maintenanc...