Objective Control Cuts Development Time, Enhances Customer Communication and Increases Component Re-use with I-Logix' Rhapsody

based in Ohio, provides consulting and mentoring services in the area of industrial process control and Object-Oriented Analysis and Design for application to real-time systems. Objective Control focuses on major process control suppliers within North America, as well as process industry control users worldwide. Control used Rhapsody to develop a system that controls the zinc coating applied to steel in a continuous galvanizing process. Their initial release focuses on improving quality and uniformity of the coating on "hot-dip" lines, where the continuous strip of steel is immersed in a bath of molten zinc, and the excess is wiped off with a jet of air or nitrogen from "air knives." Improved uniformity permits the steelmaker to produce material of higher quality while using less zinc. There is high value associated with improved control with realized savings of $1,000/day or more in zinc, as well as reductions in scrap or the need to downgrade off-spec material. Objective Control used object-oriented languages for the development of real-time systems for over 18 years. Like many other companies, prior to object-oriented methods being published, Objective Control developed their own design methods. "We were in close touch with the object-oriented community during that time, and learned what others like Rumbaugh, Booch, Jacobson, and Harel were doing from early papers, conference presentations, and personal discussions well before their methods became mainstream," said Bob Wilhelm, Partner at Objective Control. "As a result, much of our previous design work could be expressed directly in Rhapsody. For example, our first object-oriented project in the 1980s was a complete redesign of a scanning measurement system for sheetmaking processes such as paper and metals. The coating weight system we interface with in our galvanizing application is very similar, so the design of our interfacing logic borrowed much from the earlier measurement system design." With Rhapsody, Objective Control is able to develop their application graphically utilizing the standard UML. Having long adhered to the Jacobson's Use-Case method for requirements analysis, Objective Control makes substantial use of Use-Case diagrams and Sequence Diagrams to formalize the requirements for the system. Acting as the primary input mechanism, Use Cases allow for the description of major function points within the system. Once those functions are defined, Sequence Diagrams are then used to detail specification of system requirements and collaboration between objects over time. During the early phases, Objective Control rigorously avoided assumptions about the internal design of …