Basic Types of System-Models
To model a system accurately, there are typically three different domains that you must analyze:
● Discrete Event / Modal Operation—Finite State Machines are most commonly used for the modeling of the discrete event / modal operation of the system. The Harel Statecharts contained in Rational Statemate offer powerful extensions to the traditional finite state machines.
● Time-continuous / Control Loops—Time-continuous / Discrete Control-Loop analysis is performed by mathematical models that accurately represent the behavior over time.
● Performance—Performance Modeling based on queuing theory is used to determine the system characteristics of throughput, response time, and resource utilization and contention. Typically the elements in the system will be modeled to a basic level of functionality to ensure the accuracy of the analysis.The reason the domains are shown as overlapping is that most systems under design are a combination of these different domains. Therefore, to model the system accurately, the different models must be linked to provide a complete system analysis.
This brings us to the most important role of Rational Statemate as a tool for Systems Engineering. Through the Functional Model (Activity-charts), Rational Statemate provides the overview of the entire system. This enables you to define the system functions and interfaces so that you can model blocks in different domains/tools. It also brings together models from different domains to provide a complete system analysis. Rational Statemate therefore is a powerful tool for system integration and test development.