Architecture Description Language(ADL)

Architecture Description Language

Software Architecture: ADL Perspective

•      The ADL community generally agrees that Software Architecture is a set of components and the connections among them.

–     components

–     connectors

–     configurations

–     constraints

Why Architecture Description Languages?

Architectural descriptions were often informal and ad hoc. As a result:

Ø Architectural designs were not always properly understood as it was highly ambiguous.

Ø The constraints assumed (i.e. the architectural constraints) in the initial design were not enforced (sometimes) as the system evolves.

Ø Very few tools available to help the architectural designers.

To address these problems, ADLs were introduced.

What is ADL ???

Ø Architecture description languages (ADLs) are formal languages that can be used to represent the architecture of a software system.

Relation of ADL’s to other notations  and Tools

 Elements of ADL

•      Components

–     Primitive building blocks

•      Connectors

–     Mechanisms of combining components

•      Abstraction

–     Rules for referring to the combination of components and connectors

Important Properties of ADL

•      Composition – composition of independent components and connections

•      Abstraction – need to describe design elements clearly and explicitly

•      Reusability – ability to reuse components, connectors in different architectural descriptions

•      Configuration – ability to understand and change the architectural structure

•      Heterogeneity – ability to combine multiple, heterogeneous architectural descriptions

•      Analysis  - possible to perform rich and varied analysis of architectural description

•      The positives

•      ADLs represent a formal way of representing architecture

•      ADLs are intended to be both human and machine readable

•      ADLs support describing a system at a higher level than previously possible

•      ADLs permit analysis of architectures – completeness, consistency, ambiguity, and performance

•      ADLs can support automatic generation of software systems

•      The negatives

•      There is not universal agreement on what ADLs should represent, particularly as regards the behavior of the architecture

•      Representations currently in use are relatively difficult to parse and are not supported by commercial tools

•      Most ADL work today has been undertaken with academic rather than commercial goals in mind

•      Most ADLs tend to be very vertically optimized toward a particular kind of analysis

Types Of ADLs

Ø ACME

Ø Rapide

Ø Wright

Ø Unicon

Ø Aesop

Ø MetaH

Ø Lileanna