This viewpoint plays an important role in the analysis of performance and
scalability, since it relate the physical infrastructure to the logical world of
applications. It is very useful in determining the performance and quality
requirements of the infrastructure based on the demands of the various applications
that use it. In Chap. 8, we will describe a quantitative analysis technique that can be
used to determine, for example, the load on the infrastructure, based on its use by
applications (and their use by business processes).