Software architecture and reuse-an inherent conflict?

Software architecture focuses on the overall structure of a software system. The structure is defined by its components (subsystems) and the relationships between them and is often described in shorthand by such terms as model-view-controller, client-server, pipe and filter, etc. We focus not only on the reusability components themselves, but on the reusability of their interconnections as well. The interconnections could take on various forms e.g. aggregation, inheritance, frameworks, etc. Software architecture goes beyond the scope of classical software design in which the structure of a software system is mainly defined by a functional decomposition of its primary subject matter. Software architecture explicitly considers not only the functional but also the non-functional aspects of software systems, such as reusability, changeability, maintainability, portability, interoperability, testability, efficiency, fault-tolerance etc. Desirable non-functional properties have a strong influence on the architecture of the software system. Careful consideration should be given to the relative importance of the multiple nonfunctional requirements at an early stage in the software development lifecycle because their objectives are often contradictory. We focus on how the non-functional property reusability relates to the software architecture of a system