A Reusable Framework for Rolling MillsEsprit Project 22897
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In December 1996 the EU Commission signed a project contract with the REFORM consortium in the frame of the Information Technology Program Esprit. REFORM (Reusable Framework for Rolling Mills) aims to develop and implement a reusable object-oriented software architecture (framework) for process automation of rolling mills.
REFORM involves a total cost of approximately 3 Million ECU over 3 years. The project consortium is built of the enterprises Siemens (Germany, coordinator), Mandator (Sweden), UNI SOFTWARE PLUS (Austria), Voest-Alpine Stahl(Austria) and the Universities of Linz and Hamburg. The partners were selected in order to maximize the outcome by contributing the complementary skills in domain knowledge, software engineering, modern software architectures including design patterns, software development process modeling, machine learning and constraint logic programming. That the REFORM project has a good economic potential can be clearly demonstrated by the fact that currently process automation systems are rewritten from scratch for every new rolling mill, in spite of the possibility that 70% of the code of such systems could be reused. Analyzing the cost/benefit ratio with regard to the market volume and forecasted market shares, a return on investment period of less than 3 years is expected. Nevertheless the technical feasibility was probable but not proven at the project start. Even taking into account that REFORM has its base in highly innovative technologies in its domain, it needed to be demonstrated that a system of this complexity can be implemented in the proposed generic way represented by an object-oriented framework. To minimize this risk, the framework is structured into subframeworks, the development process is strictly prototyping-oriented, prototypes are fully tested in a simulation environment semiannual reviews with independent experts are conducted by the project coordinator of the European Commission and the REFORM results will be verified and validated at the trial site of Voest-Alpine Stahl under real production conditions. This outlines, that REFORM has the typical characteristic of a research project but is demand-oriented with a clear exploitation strategy. Consequently funding of more than 50% of the total costs was accepted by the European Commission.
The first two years of project work have confirmed the technical feasibility of the undertaking. Moreover, process automation can be seen as object-oriented in nature. The project is in the stage of consolidation, tuning and refinement. The remaining year will involve the assimilation of the current results into the trial automation system at Voest-Alpine Stahl in Linz in order to demonstrate that the REFORM results not only speed up software development and time to market but also improve its quality and the quality of the finished products of the rolling mills.
The consortium is confident that its commercial partner Siemens can exploit the REFORM results immediately after the project end in November 1999 and use the framework as a basis for its next generation of process automation systems.
From a course-grained perspective, one hot rolling mill looks like any other; a pushing furnace to heat the slabs, heavy edge, rolling stands, and a cooling section transforming the slabs into metal strips. From a finer grain, namely the interface to the basic automation system, two hot rolling mills can look like completely different plants. Signals, measured values and control information come in certain frequencies and need to be processed on a higher level in order to optimize the process towards product quality, energy consumption and scheduled time frames. The difficulty of the traditional approach with procedural languages like C in process automation for rolling mills lies in the transformation of cooperating tasks of components, aggregates and measurement devices in a certain plant configuration into a procedural paradigm. It is therefore intelligible that developers reuse knowledge, but in many cases instead of analyzing and adapting existing procedural code rewrite all functions completely. Adaptations need offline "compile, link and go cycles" before a new functionality can be installed at the user site.
The most difficult development task in this approach is to find the right key abstractions in order to make the implementation of the components as general and customer-independent as possible. The REFORM architecture uses components based on object-oriented frameworks. As semi-finished software systems, frameworks implement the customer-independent parts of the problem domain. Nevertheless, these parts are open for customer-specific extensions. As prebuilt functional parts of the process automation system, components allow users to configure their software even at run time.
The consortium has agreed upon a common software development environment, technical guidelines and coding conventions, documentation, and configuration management. Common office tools and shared document templates facilitate cooperation. Additionally, development is guided by organizational provisions like a development process model.
Nevertheless, the partners' need to reach a maximum of cohesiveness in such a collaborative project was underestimated at the beginning.
A consortium for such a complex project needs to reach a degree of cooperation where the reallocation of tasks and efforts can be managed across partner borders, in agreement with the whole consortium.