A method models a manufacturing process. The modelling is performed by a business layer and an execution layer. The method includes defining a generic equipment class containing a first placeholder, defining at least one generic process segment class associated with the generic equipment class and containing a second placeholder, defining a specific equipment sub class derived from the generic equipment class, and defining a specific process segment sub class derived from the generic process segment class. The specific process segment sub class is associated with the specific equipment sub class and models the manufacturing process by using the first and second placeholder on the business layer. The business layer is responsible for planning decisions at the level of the placeholders representing the generic classes of equipment and process segments. The execution layer is responsible of scheduling decisions at the level of the specific sub classes of equipment and process segments.