||Along a supply chain hundreds and thousands of individual decisions have to be made and coordinated every minute. These decisions are of different importance. They comprise the rather simple question "Which job has to be scheduled next on a respective machine?" as well as the very serious task whether to open or close a factory. The more important a decision is, the better it has to be prepared. This preparation is the job of planning in its widest sense. Planning supports decision-making by identifying alternatives of future activities and selecting some good ones or even the best one. Planning can be subdivided into the phases: recognition and analysis of a decision problem, definition of objectives, forecasting of future developments, identification and evaluation of feasible activities (solutions), and finally selection of good solutions. Supply chains are very complex. Not every detail that has to be dealt with in reality can and should be respected in a plan and during the planning process. Therefore, it is always necessary to abstract from reality and to use a simplified copy of reality, a so-called model, as a basis for establishing a plan. The "art of model building" is to represent reality as simple as possible but as detailed as necessary, i. e. without ignoring any serious real world constraints. The main objective of this subject is to introduce quantitative methods and techniques aimed to help the planning activities and, therefore, to support the decision making process. These methods are based in the use of formal models and their corresponding solving techniques. The student will learn how to model the system and its decision making process and then how to apply the methods and techniques to select the optimal solutions. Basic case studies representing typical problems (e. g. planning, scheduling, distribution or routing) are used in the learning process.