The operations scheduling problem in electric power systems is to determine which generating units should be on-line and available for generation at each hour and the associated nominal generation or dispatch. This paper describes the scope of the operations scheduling problem, presents mathematical formulations to the problem, and surveys recent advances in optimization-based solution methods. It is mainly concerned with the shorter term aspects of the problem where the time horizon is of the order of a week. The unit commitment, short-term hydro scheduling, and hydro-thermal coordination problems as well as solution methods are emphasized.

A model developed for optimal allocation of sampling resources in a surveillance system designed to enforce certain environmental standards is described. While the presentation is done in the specific context of a wastewater effluent pollution surveillance system, the methodology developed is potentially useful in other environmental areas. The surveillance system considered is one applicable to a finite number of sources, each containing one or more contaminants. A source can be sampled to determine whether any of its contaminants exceeds a maximum allowed value. If such an excess is detected, then the source is said to be in violation. The objective is to allocate the sampling resources for each source during a certain monitoring period such as to minimize a certain performance index, subject to a budget constraint. This performance index is taken as the expected environmental damage due to the undetected violations. The resulting optimization problem, which is of the integer programming type, is shown to be amenable to solution via the method of maximum marginal return.