Production planning problems containing special characteristics from process industries are addressed in this book. The main subject is the development of mathematical programming models that allow to model production plans which are not disrupted by discretization of time. However, discrete time models are used as a basis and are subsequently enhanced to include aspects of time continuity. Their integration is achieved by different building blocks which may be combined freely according to the specific planning situation at hand. The primary area of application of these kinds of models are process industries.