Integrated framework of IDEF modelling methods for structured design of shop floor control systems

Abstract

The information architecture for a shop floor controller provides the accurate and relevant data in an appropriate format. The information architecture is built by specifying the information requirements and by defining the information handling mechanism. The objective of the paper is to capture and specify the information requirements of workstation and machine controllers for hierarchical shop floor control in a discrete part manufacturing system. The information contents managed by the workstation and machine controllers are identified through IDEF0 function modelling activities. The IDEF0 function modelling method is used in order to guarantee the complete capture of the required information contents. Once being captured through inputs, outputs, controls and mechanisms of the function model, they are classified into two categories: message and stored data. The flow models and specifications of the identified messages are presented using a variant IDEF3 process modelling method. Since the sequence of the messages does not appropriately appear on the function model, a dynamic message flow model is needed which describes message flows among controllers and functional modules. The captured data and their semantic relationships are modelled using the IDEF1X data modelling method. In particular, the evolution of planning and scheduling data is also identified and modelled as part of the information requirements. The specified information requirements show an integrated view of context of a SFCS, increase the understanding of functionality of a SFCS, and provide the stable basis for the SFCS development. The approach suggested in this paper can avoid the fatal errors in terms of information management in operating shop floor control software.