An approach to schedulability analysis of UML-based real-time systems design

• Authors: Dongxi Jin;David C Levy
• Venue: WOSP '02 Proceedings of the 3rd international workshop on Software and performance
• Year: 2002

This paper presents an approach to analyzing the timing and schedulability performance of a system model designed with the Unified Modeling Language (UML). As demand grows for a better way of developing complex real-time (RT) software systems, object-oriented modeling and design has recently gained popularity in real-time circles. However, due to the timing constraints in RT systems, appropriate approaches are needed to complement the software design methods, so that the design model can be analyzed in terms of schedulability as early as possible during the high level design phase. Transaction spatial and temporal models are introduced in this paper, to provide a way of bridging object-oriented design models using UML and real-time schedulability analysis. Identifying the transactions starts with viewing UML models from the perspective of transactions. Based on the captured transactions, the transaction spatial model is explored by using the object sequence diagram, where the system behavior is decomposed into action-based transactions in terms of object and message inside the system. The transaction temporal model then is captured by analysis of the UML-based transaction spatial model, and a table of transactions and their timing is constructed from which end-to-end response times may be calculated. As a result, performance analysis can be conducted to the UML-based high level design model. To illustrate the approach, a velocity control system for a direct current (DC) motor is analyzed.