What's the point of Software Architecture?

At the SPA 2008 conference, I attended a session entitled 'Does Architecture Help?' in which Eric Nelson from Microsoft identified 9 observations on architecture that he has encountered from his work with Independent Software vendors (ISVs). He noted that there was no correlation to project success if there isn't an architecture and that there are many different ways (read architecture) of solving the same problem. Although there isn't a perfect architecture, there are clearly examples of bad architectures, which are often demonstrated by symptons such as change being very expensive, that have delivered a great service possibly through the massive advances in hardware technology being 'the get out of jail card'.

The rise of agile developments has clearly impacted the importance of architecture with perhaps the removal of the formality of this activity. Clearly the availability of technology can have significant impacts on software architecture. While there is always the tempatition to try and accomodate the latest technology in your next project, I think this is a risky strategy as architectures normally need to be based on firm foundations (there are always exceptions). With a good architecture (not a perfect one!), it is possible to keep technology choice separate from the architecture. In my experience of Model Driven Architectures (MDA), it is possible to separate the technology from the architecture through the use of separare models:

• Platform Independent Models (PIM) which is independent of a the technical choice


• Platform Specific Model (PSM) in which the technical choice is made

The slides for the session are available from Eric's blog.

I discovered something when I downloaded the slides, a new file extension .PPTX. My computer didn't recognise the extension (I only had Microsoft Powerpoint Viewer 2003 installed). A hunt around Microsoft's website revealed a free download for Microsoft Powerpoint Viewer 2007 which adds the capabilty to view .PPTX files, which I discovered are Powerpoint files stored in Microsoft's new XML file format.

Are we nearly there?

The first panel at the SPA2008 Conference addressed the interesting topic 'Is Software Practice Advancing' with particular reference to the last 15 years. In summary, the panel said 'Yes, just!' after considering programming languages, software design and project management.

There hasn't been much advances in programming languages over the last 15 years (new languages such as C#, Javascript were cited) although some languages have become more popular (e.g. Haskell, Ruby) and others are now only used in maintenance tasks rather than new developments. Tooling for languages has improved with such toolsets as Eclipse, Visual Studio and IntelliJ aligned with better compilers although it is debatable if this has produced any significant change (reduction?) in development costs. There is also an increasing number of open source tools which are free which is a noticeable change for development. Programming is still unpredicatble and the risk of things going wrong hasn't changed. While languages haven't changed, there has been some significant improvements in libraries and frameworks which lead to some gains in the development life-cycle.

COMMENT: I would say that there are an increasing number of languages which are now available and supported due to the convergence on to two development platforms (Unix (and all flavours of) , and Microsoft) as the use of proprietary systems has diminished. However, the days of the coder maybe numbered as an increasing number of tools can now auto-generate significant amounts of code.

Software Design also hasn't changed significantly in the last 15 years although the debates about OO notations being finally resolved with the release of UML. Maybe what has changed is the way software is now assembled as there is now acceptance that using open-source components and 'glueing them together' is more than adequate for many applications and demonstrates good software re-use. More complex (and better?) systems are now being produced although the design skill level hasn't changed; it may actually have decreased as design becomes unfashionable as the need to 'write code and get something working' results in formal design processes being side-stepped. The production of software architecture has improved and is recognised as being of value to all developments.

COMMENT: The rise and maturity of the open-source is now having an increasing influence on software developments - the development and adoption of standards has probably helped this. The rise of the web has probably contriubuted to the loss of design fomality. There is still no substitute for expereince when designing systems. The use of tools to support the design process, particularly for large systems which are adopting model-driven developments, could lead to some changes in the perception of design and result in changes in effort profiles for software developments as the emphaisis changes to design and integration rather than coding.

The final section of interest covered project management where it was remarked that some techniques have improved, the practice is still poor. Projects have got bigger and bigger and the probability of failure has only marginally decreased over the last 15 years (still >70% chance of failure). The widespread adoption of agile and iterative life cycles over the traditional waterfall life cycle has not been as dramatic as the noise made by the agile community would have us believe.

COMMENT There is no precise definition of what Project Management is as it can cover a vast array of activities depending on the size of the development. Some approaches have been made e.g. OGC, PRINCE, DSDM to try and formalise the activities but these don't adequately address a badly specified and procured system which are often root causes of many project failures.