A manufacturing model to capture injection moulding process capabilities to support design for manufacture
The achievement of "better, faster, cheaper" product designs is heavily dependent on providing appropriate information to design teams. One of the essential parts of the information is the manufacturing process information. The aim of this research has been to explore the representation of the capability of the injection moulding process in a software form. The resulting model termed a Manufacturing Model must provide a common source of information to a range of interacting Design for Manufacture applications. These applications in turn would produce feedback advice as the design evolves, to the users in order to assist in their design decisions. The manufacturing information to support injection moulding process has been categorized as mouldability features, mould elements and injection mould machine elements which represent the main entities of the Manufacturing Model. The EXPRESS language and EXPRESS-G have been used to provide a formal non-software dependent representation of the underlying structure of the Manufacturing Model. To explore the use of the Manufacturing Model information to support Design for Manufacturing (DFM) applications the Object-Oriented methodology of Booch has been used. Three DFM applications have been considered, these being Desigu for Mouldability, Supporting Mould Design and the Selection of Injection Machine. An experimental Manufacturing Model, based on the EXPRESS representation, and related DFM applications have been implemented in Object-Oriented form using LOOPS (Xerox 1988). This has been used to show that the capability of the injection moulding process has been captured in the Manufacturing Model and provides support to a range of interacting Design for Manufacture applications. While the EXPRESS language has provided a good tool to capture the structure of the Manufacturing Model, further work has been required to define the functional interactions between entities within the model. Using the object oriented paradigm to implement the Manufacturing Model has been demonstrated. The Booch methodology in addition to EXPRESS has provided the basis to model the functional interaction between the Manufacturing Model entities. As an implementation tool, LOOPS has proven to provide adequate object oriented capability. However there is requirement for software tools which can readily be integrated with other software tools. The research has provided a contribution to a structured, and extensible, approach which should influence future CAB system structures aiming to provide support to Concurrent Engineering.