A paradigm for the integration of real-time monitoring and MRP II

Abstract

The objective of this research is to design a methodology for integrating Manufacturing Resource Planning (MRP II) systems and Supervisory Control and Data Acquisition (SCADA) systems. The aim is to enhance data integrity, data consistency and data accuracy of the execution phase of MRP II applications through the use of real-time data provided by real-time data capturing systems. Although there are numerous methods established to enable real-time data in MRP II applications, these methods are application dependent and none of them can be considered as a general methodology. This is further hindered by the unlimited hardware and software standards in the past; it is difficult to provide a solution in an infinite, diverse, dynamic and unpredictable environment. With the advancement of software engineering technology, a universal standard (i.e. OLE for Process Control), for data interchange between field devices and software was available in the late 90's. This evolution created a finite environment for this research that has not been possible in the past. Early studies indicate that integration is not only difficult to construct properly for the first time, but more significantly, that it is often difficult to specify correctly the first time. To overcome these pitfalls, the proposed integration methodology is based on both theoretic and pragmatic premises. The integration methodology contains three key elements: a data model, a collection of modeling heuristics, and a method of implementing the designed model. The model is a data representation of real world objects and operations. It employs the Hierarchical Object-Oriented Design (HOOD) tree as the core data structure. The HOOD tree is devised from the HOOD method that is a proven technology for designing real-time mission-critical application in both the academic and the industry field. The complexity of the model is mirrored in the size and structure of real-world entities. Hence, the proposed methodology provides a consistent manner to form the data model. Modeling heuristics are apparent to transform the HOOD tree from a physical model to a logical model. Various optimization strategies that are based on the rule of inheritance and polymorphism are also introduced in this research for the effective use of a data model. To validate the proposed methodology, case studies were carried out with the help of a collaborated company as a Teaching Company Scheme project. The results indicated that the proposed methodology is a feasible solution to integrate MRP II systems and SCADA systems. Two industrial projects are successfully implemented based on the integration methodology developed in this research.