Performance analysis at the software architectural level

This work gives an overview of performance analysis at the software architectural level and methods available for that purpose. Architectural level analysis means analysing the quality of the software in the early development phase based on software architectural designs and estimated timing information. The basic idea related to performance analysis methods is to derive a performance model based on software architecture, which can be analysed and feedback about the performance of the planned software is obtained. The goal of this work was to analyse the performance of the part of a mobile phone software that is executed on the Symbian operating system during concurrent streaming and multimedia message reception. It was analysed by applying the PASA method, but as a deviation from the method LQN was used for performance modelling. The analysis was conducted mainly by calculating utilisation, residence time and queue length based on the LQN model and estimated execution times. The calculated values were compared to performance objectives and then it was concluded that if the execution times were as estimated in this work then performance objectives would be met on average, but in the worst-case condition performance problems could occur. It was proposed in this work to change the priorities of the related tasks according to RMA principles. Then the deadlines would be met even in the worst-case. In this work performance was analysed only from the processor point of view, so the effect that other hardware resources (such as memory or buses) have on performance was not considered.