Planning and operations problems are complex and require detailed and accurate modeling to be solved effectively. At the same time there is also continuous change: For example, modifications to schedules, changes to agreements, and disruptions of plans. The challenge is to be able to adapt quickly to a changing environment and to model and solve the problems accurately. We describe a special purpose modeling system, the Carmen Rave language, and its application in planning and operations. We also give concrete examples and address various aspects of problem solving.