A practical approach for performance-driven UML modelling of handheld devices – A case study

In this article, we present a performance engineering enhanced modelling methodology for designing embedded devices and describe the experiences we have gained in applying this methodology during the design of a DVB-H enabled handheld device. The methodology uses UML 2.0 to model the system following a strict separation of architectural and behavioural aspects of the system. For this purpose we employ the new composite structure diagram and show its advantages over already established approaches. This methodology specially aims on an easy application by non performance experts. From the model, a multiclass queueing network is generated for the analysis of the system performance. The configuration of hardware resources and resource demands is done using the standard SPT Profile which is extended where necessary. This makes queueing theory accessible to system designers even if they are not familiar with the underlying mathematics. In this way the acceptance of developers to use performance engineering in their daily work is increased. Special attention has been put on an easy evaluation of design alternatives. We describe our implementation and its seamless integration into a UML 2.0 CASE tool.