Introduction Better Faster Cheaper (pick any two) On-going issue that continues to motivate research in software engineering Applications: –continue to increase in size and complexity –need to be deployed quickly –maintenance can be ~40% of the development cost –…–… Re-use approaches proposed as solutions

Software Engineering Discipline Current Issues? –“tyranny of decomposition” problem –Improve re-use of components –Support “mass customization” of software –Architectures for Dynamic Adaptable Systems –… Active research area –Upcoming Architecture Events page maintained by the SEI currently lists 14 conference workshop events/special issues –

Different paradigms share common themes –Definition of re-usable “chunks” Agents in agent-oriented development Aspects in aspect-oriented development Services in service-oriented development Core assets in product line development … –Communication among the “chunks” –Composition of the “chunks” –Use of repositories to organize/store the “chunks” –Visual modeling for improved communication Note. There are UML extensions available for a wide variety of recent paradigms –UML for aspects –UML for services –UML for agents –… –Tool support Research/experimental tools vary widely in maturity (documentation, robustness, completeness) Some things to look for… (or look out for)

A posting to consider… …in time we will construct reusable components and many architectures and someone will ask for such a system, performance, money then integrators will decide on the components and the hardware – see u bye Up to that time we will read, research and invent "x- orienteds" every day..... x may be : object, aspect, service … maybe i should write a methodology Tolga-oriented software development :) Tolga Erdoðan Adapted from posting on Requirements- March 16/08

Aspect-oriented Paradigm: Issues Introductions to the aspect-oriented paradigm are at: Traditional modularization mechanisms suffer from a limitation called the tyranny of the dominant decomposition –the system can be modularized in only one way at a time –concerns that do not align with that modularization end up scattered across many modules and tangled with one another -> Higher coupling, lower cohesion

Aspect-oriented Paradigm: Issues Aspects have been proposed as a solution to the problem –New entity to encapsulate a (crosscutting) concern –Aspects have: Pointcuts - provide the definitions of where and how an aspect will cut into the design. Advice - provide functionality when the aspect is invoked.

Aspect-oriented Paradigm Started at the programming language level –Aspect-oriented programming (AOP) –AspectJ, HyperJ, AspectC++, … Aspect-oriented modelling (AOM) followed –Architecture, Design, and Requirements –UML has been used/extended by a number of researchers for our needs (architecture, design) Some people argue that extensions are not needed; others argue they are needed Of the UML extension mechanisms used, stereotype extensions are the most straightforward >

Aspect-oriented Paradigm This is an active community –Annual conference and journal International Conference on Aspect-Oriented Software Development AOSD ( ) Transactions on AOSD Comprehensive surveys are available: For example This survey report is cited by many; however note the date (2005).

9 Aspect-Oriented DesignObject-Oriented Design Problem Statements Aspects added one at a time Security Adaptability Advantages: Tangling aspects handled separately, Dramatically reduce the complexity of understanding, change, and analysis, promoting reusability … Module 1 Problem Statements Module 1 weaver Final Design Problem: lower cohesion, higher coupling, maybe significant re-work when facing changes Final Design Security Performance Adaptability Aspect-oriented Paradigm: Issues

Aspect-oriented Paradigm: Architecture/Design What would an aspect-oriented architecture/design look like? It depends… Let’s take a look at a couple of examples 1.UML-AOF 2.UML Formal design analysis framework 3.ADL?

FDAF Step One: Extend DNS architecture design with data origin authentication aspect Aspect-oriented Paradigm: FDAF

FDAF Step One: Extend DNS architecture design with data origin authentication aspect (cont.) Aspect-oriented Paradigm: FDAF

Project Management? Maintainability of the software is key focus for the aspect-oriented research community Question: How does adopting this paradigm this impact the PM?