background: several reservoir systems have been constructed for hydropower generation around the world. hydropower offers an economical source of electricity with reduce carbon emissions. therefore, it is such a clean and renewable source of energy. reservoirs that generate hydropower are typically operated with the goal of maximizing energy revenue. yet, reservoir systems are inefficiently ope...

The increased complexity of modern manufacturing has led to uncertainties in production processes. Factors such as unplanned machine maintenance, tool unavailability, and complex process adjustments make it difficult to maintain a predictable level of output. To be effective, an appropriate production model must incorporate these uncertainties into the representation of the production process. ...

since data envelopment analysis (dea) introduced in 1970s, it has been widely applied to measure the efficiency of a wide variety of production and operation systems. recently dea has been extended to examine the efficiency of decision making units (dmus) with two-stage network structures or processes, where the outputs from the first stage are intermediate measures that make up the inputs of t...

We address multi-item inventory systems with random and seasonally fluctuating, and possibly correlated, demands. The items are produced in two stages, each with its own lead-time; in the first stage a common intermediate product is manufactured. The production volumes in the first stage are bounded by given capacity limits. We develop an accurate lower bound and close-to-optimal heuristic stra...

To save overhead and penalty costs, in many cases of Multi-Period Multi-Product (MPMP) planning systems, reducing the completion time is highly desirable. Therefore, in this paper we study this problem. We propose an approach in which a MPMP problem is converted into a project management network. Then, considering network concepts and properties, a multi stage novel mathematical model is propos...