Classifying and modeling exceptions through object process methodology

Exception handling is a fundamental issue that needs to be addressed by complex systems such as embedded systems, real time systems and medical information systems. Modeling exceptions appropriately is a crucial step in a system design process, since correcting errors detected after the design phase can be very costly. Object Process Methodology (OPM) is a methodology that uses a single graphical model for describing systems, including their timing exceptions, and has been shown to be an effective modeling methodology. We developed a taxonomy of exceptions, and refined and extended OPM for expressing the different types of exceptions and their detection and handling. We exemplify the introduced concepts using a case study of a cellular phone, taken from a real industrial system.