There has been much debate recently over the fate of "service-oriented architecture" (SOA).
In January, Burton Group analyst Anne Thomas Manes declared the term effectively dead, a victim of the hype muddying its meaning and the budget cuts affecting large IT projects.
The discussion continued at the SD West conference in Silicon Valley earlier this month, where a series of panellists tore strips off SOA.
David Platt, author of "Why software sucks and what you can do about it" said, "Like any other buzzword it got thrown at everything to see where it would stick."
But, although a majority feel the term has been devalued, even its harshest detractors believe the fundamental concept it embodies - a set of loosely coupled, interoperable business services which talk to one another using open web protocols - is very much alive.
Such an approach allows organisations to build and deploy new applications and services quickly, using whatever mix of in-house and external services best serves their needs.
As Thomas Manes wrote, "SOA is survived by its offspring: mashups, business process management (BPM), software as a service (SaaS), cloud computing and all other architectural approaches that depend on services."
Dennis Quan, director of autonomic computing development at IBM, drives much of the company's cloud computing agenda. He thinks SOA will be critical to the emerging cloud IT landscape.
"SOA is still very much in play. Cloud computing is about delivering highly scaleable services across the network and right at the heart of that is the notion of services.
"In the beginning, a lot of the focus was on software as a service, but today we are seeing it applied more broadly, with the emergence of things like processing power, platforms, storage and applications as a service - delivered from large, scaleable (and often multi-tenanted) datacentres. SOA provides the framework both for managing the cloud centre and tying together services into the composite applications customers end up using," he says.
Analysts such as Gartner have been talking up cloud computing since the crunch, lauding its potential for cutting costs. It is true many firms are looking at consolidating server farms by virtualising their infrastructure - but how many have made a strategic commitment to deploying a service-based architecture on that virtualised infrastructure, or plan to use externally-hosted cloud services?
Nick Kirkland, chief executive of IT leaders' forum CIO Connect, says, "It is a very, very small proportion. The service providers who support this stuff have a very gung-ho, can-do attitude. But the message we are getting back from our members - some of the most senior CIOs in the country - is that they are listening, but they are not convinced yet.
"There tends to be a range of thoughts from the high-level 'this could change our cost model' to the low-level 'Google Mail went down last week - how could I run a business on that sort of thing?'.
"Fundamentally, people are still asking what this actually means. Indeed, we are running a briefing on this shortly to try to clear up some of the confusion."
But he stresses interest is rising, and more CIOs are "dipping a toe in the water".
"An increasing number are trying out cloud computing in a careful way for projects that do not involve sensitive data," Kirkland says.
But corporate CIOs need to balance the much-touted cost-efficiency benefits against issues such as information security, project management, availability, governance and data portability. Since cloud standards for all these issues are still evolving, CIOs of large organisations are unlikely to buy wholesale into the concept of cloud-based SOA just yet.
Psychometric testing provider SHL has been using the cloud for a year for development and trialling purposes. Chief information technology officer Andy Ross says, "We are very pleased with the results: it was quick and very cost effective to set up with the provider we used.
"We do have to put more daily-type support in than we would like, and for that reason we see it as a development or quasi-production tool rather than a full-blown production environment - but I can see that coming.
"We are a Microsoft shop and fully virtualised using Capgemini's utility infrastructure so we are already part-way to achieving the full flexibility of the cloud. My advice would be for rapid trialling and development, you should try the cloud. For production, we want to see a bit more maturity."
But IBM's Quan says it is vital to separate the idea of public cloud computing (where an external provider offers hosted, cloud-based services to clients, such as Amazon's EC3 and S3 cloud-based processing and storage services, or Google's Apps suite) from internal or private clouds.
The latter, Quan says, can be employed as the basis of an organisation's SOA without putting data or processes at any more risk than normal. "There has been a lot of attention placed on public cloud centres, but we believe the private cloud - whether managed in-house or by a trusted provider - is central to the hybrid cloud computing strategy we think will become dominant in the next two years.
"With the right architecture in place, cloud-based datacentres offer organisations lower management costs, the ability to bring services online very quickly, and elasticity of resources. At the same time, they are able to gain these economic benefits while still retaining fine-grain control over their data security and governance models," he says.
Guy Bunker, chief scientist at Symantec and a member of cross-sector security task force the Jericho Forum, agrees private clouds mitigate many of the risks for large organisations. But he also believes companies need not eschew public cloud services completely, since these will likely form a major part of corporate IT once standards have settled down.
"Some of the companies using the cloud in earnest - such as big pharmaceutical companies like Eli Lilly and AstraZeneca - are doing exactly that. They are using Amazon's EC2 for certain services, but not for those handling any sensitive data.
"Large organisations should look at public cloud services, but they need to be aware of the pitfalls so they can ask the right questions of their providers.
"Then, depending on their appetite for risk, they can decide whether a particular function, application or whatever is suitable for the cloud given its current state of maturity," Bunker says.
While private clouds offer significant benefits for risk-cautious businesses, Richard Hall, founder of cloud computing consultancy CloudOrigin and an experienced former corporate chief technology officer himself, believes the sheer economies of scale achieved by public cloud providers will inevitably mean they dominate in future.
"Although there may be some benefits looking at internal clouds, particularly as a sandbox to explore concepts, I suspect the real commercial benefits (savings on infrastructure and, unfortunately, headcount) will kick in only when an organisation moves to a major public cloud platform," Hall says.
In 2009, the companies with most to gain from cloud computing will be industrial-scale users of infrastructure looking for major savings, or startups who never want to make heavy IT investments. Such companies should be looking at the architectural choices for cloud platforms with respect to software design and infrastructure deployment.
Many will actively trial technology and approaches this year, with a view to deployment into 2010 as the major platforms such as Windows Azure mature into production," says Hall. "Then I think the first few snowflakes we are seeing now will turn into a full-blown avalanche," he says.
Case study: Isle of Man
On a budget he jokes is "less than John Prescott's expense account", Allan Patterson, director of the Isle of Man's government information systems division, has delivered an internal cloud-based SOA that could be a showcase in microcosm for what much larger organisations will be doing in future.
"It is what I would call 'building a virtual house'," says Patterson.
"The foundations are our twin active virtualised datacentres running on a Windows platform and our IP network across the whole government estate of 250-300 locations - GPs' surgeries, schools, sub Post Offices, etc.
"On top of that is the equivalent of the pipework and wiring - the common services - which mean we can build something once and use it many times."
This has drastically reduced the IT organisation's costs, but also brings wider benefits.
Patterson says, "We have seen a massive take-up of online services such as web payments by the business community and individuals - we now have about 5,500 users for online services, which for the Isle of Man is huge.
"I strongly believe this is how we make government-to-business more effective. We have even got people who no longer maintain tax books because they trust us to do it - so there are efficiencies for end-users as well."