A manufacturing execution system contains a depicting device for depicting at least a part of a productive process to a hierarchically structured set of entities and an application programming interface for managing data in a data base and for inputting a tree into the application programming interface. The tree representing a hierarchical relationship between at least two entities of the hierarchically structured set of entities. A program device provides a method accessible by the application programming interface. The method is adapted to manipulate the hierarchically structured set of entities. A manipulating device is provided for manipulating the entities of the tree according to the method.