After modelling and simulation of a technological or economical process the ultimate goal is the computation of optimal process parameters and solving problems of optimal control in this respect. In this main application area, methods of PDE-constrained optimal control, control of differential algebraic equations, and stochastic optimal control are employed in a variety of applications in technology and economy. These applications may range from basic production processes such as welding and hardening to the design of diffractive structures and simulation tasks in process engineering industry to optimal decision in financial environments such as financial (energy) derivatives, energy production and storage.