The new-generation Level 2 system should have following features:

1. Full metallurgical principles integrated. For example, a rolling mill Level 2 system may be integrated with over 100 rolling process models, an expert system, and advanced intelligent learning. Microstructure simulation is performed pass by pass to determine parameters such as retained strain, flow stress, grain size, grain shape, phase proportion, etc. The modeling, such as microstructure simulation, is integrated with the AI learning techniques and with an expert system, and is continuously learnt through history data. Finite element method will be used to determine, e.g. roll deflection and local draft over width. Hybrid systems will be established by combining the AI learning techniques with the empirical models, so that the models are not black boxes (as many neural networks are) and will be continuously improved with the history data.

2. Uninterrupted upgrade. The Level 2 system can be upgraded frequently using vendor-supplied or user-developed components, without system shutdown. It will be fully modularized and fully object-oriented. The system facilitates uninterrupted upgrade in three levels: service, component and DLL. A service usually consists of multiple components (including software applications) and is developed following certain IT standards (e.g., SOA, COM+). A component may be created from multiples classes (DLLs). A DLL is created from a single class, which may call other classes following object-oriented methodology. An upgrade in the DLL level may be done, for example, by simply replacing an old DLL with the new one, or by adding new DLLs to the existing Level 2 system. Therefore, with the changing industry practice, the Level 2 vendor (or the third party) can supply new DLLs, Components or services to the user. There is, therefore, no need to retire an old system and to buy a new one in, say, every ten years. The upgrade cost in this way can be minimal.

3. State-of-the-art software engineering technologies. Fully object-oriented programming technique will be combined with the interactive relationship of the mill process models. SOA will be used to integrate various applications and components, which may be initially designed for various platforms. The source code is expected to be concise, easy to understand and easy to maintain. As to the architecture, it may be a four-tier system, consisting of Operator Interface (HMI, tier 1), Level 2 Management System (tier 2), Level 2 Model System (tier 3), and Database Management System (DBMS, tier 4). The tier 2 and tier 3 can either reside in a single server or be separated in two or more servers. Due to the large number of model calculations (microstructure, FEM, Neural Network, etc.), separate servers for the tier 3 is preferred.

The next-generation Level 2 model may include following modules

• Rolling Process Models, to perform model calculations for, such as force, temperature, roll flattening, roll deflection, thermal crown, roll wear, steel deformation. It calls the metallurgical modules to determine microstructure, retained strain and flow stress, etc.

• Metallurgical Models, to determine retained strain, grain size, rolled steel properties, etc., by combining with intelligent learning such as neural network, fuzzy logic and expert system.

• Expert system, which consists of logics, data and influence factors on the mechanical, thermal and metallurgical parameters depending on rolling and thermal processes. Past mill-experiences should be programmed as a portion of the expert system.

• System Learning, based on rolling process models, in which the neural network provides the correcting factors for the model coefficients, and fuzzy logic rules and expert system provide guidelines (upper and lower boundaries, etc.) for the learning.

• Draft Scheduling, which is based on various requirements (shape, properties, etc.) and various algorithms, with special attention paid to nonlinear algorithms. Microstructure and finish properties will be predicted for every newly generated pass schedule.