Architectural styles play an important role in software engineering as they 
convey codified principles and experience which help the construction of software
systems with high levels of efficiency and confidence.
We address the problem of formalizing and analyzing architectural styles in an 
operational setting by introducing the intermediate abstraction of architectural
type.
The concept of architectural type is developed in a process algebraic framework 
because of its modeling adequacy and the availability of means, such as Milner's
weak bisimulation equivalence, which allow us to reason compositionally and 
efficiently about properties like the well formedness of architectural types and
the conformity of a given architecture to a certain architectural type.
The process algebra based architectural description language for specifying 
architectural types comes equipped with a graphical notation and allows both
functional and performance properties to be analyzed.