The paper gives an overview of the deregulated electricity supply system in Norway, with emphasis on the generation scheduling approach. Procedures and tools for long-, medium- and short-term scheduling are described. Scheduling is carried out by each individual utility. Since scheduling is based on profit maximizing, the spot market price is a very important factor; this price is varying and uncertain, however. A part of the paper describes how to deal with this by considering the spot market price as an exogenously given stochastic variable. It is shown how to extend the common water value computations so as to handle this case. Implications to the medium- and short-term scheduling are also discussed.