Specification of events and states in complex systems

Monitoring consists of collecting information from the system and detecting particular events and states using the collected information. These events and states can be symptoms for performance degradations, erroneous functions, suspicious activities, etc. and are subject to further analysis. Detecting events and states requires a specification language which makes it possible to express a wide variety of events/states easily and also allows the implementation of the efficient detection algorithm. The authors introduce an event/state specification language based on classical temporal logic. They compare the language with other languages such as relational algebra, historical relational algebra, OPS5, and an extended regular expression based language. It is proved that the language is as expressive as or more expressive than the other languages. It is also shown that the language can specify a variety of events and states more conveniently than the other languages.<>