"Delivering Software as a Service is the ultimate in SOA," says Eric Larkin, CTO and co-founder of Arena Solutions Inc., a provider of on-demand product lifecycle management (PLM) applications for manufacturing.
His company uses the SaaS model done in the SOA style to deliver Web services applications with Ajax user interfaces for handling product documentation, such as specifications for parts. The customers, who are small and mid-sized manufacturers, buy the products hosted by Arena on a subscription basis, and work with them through a Web browser-based interface that has become increasingly desktop-like with the recent introduction of Ajax.
In the seven years since Arena was founded, the architecture and technology for building SaaS applications has evolved significantly.
"We started the company back in 2000 and built it on what was at the time a state-of-the-art stack," Larkin said. "It was a scripted application server, not Java-based. That platform served us very well. It allowed us to get up to 300 customers and more than 10,000 users."
However, because the company originally used a non-standard, non-Java server, the development team at Arena spent a lot of time working out architectural issues for functionality such as statelessness in the Web tier, distributed cache management, messaging and queuing.
"We ended up as a company engineering a lot of those subsystems ourselves because we were on a non-standard technology platform," Larkin explained. "To be honest I'm pretty proud of what we did. We did a very competent job. But when you get right down to it, working out a distributed cache system is not very closely related to developing software for manufacturers."
So by 2005, he began looking for a standard platform where those kinds of functionality could either be purchased or found in open source, so the developers could concentrate on the core SaaS products.
"It really makes sense for us to move to a much more standards-based platform with modular architecture where with substantial portions of the basic technology infrastructure we can leverage best of breed solutions, either commercial or open source, and plug them into our application framework," Larkin said. "Then we can focus our development efforts on creating software for manufacturers, which is where our core expertise is."
As Larkin realized that the original technology stack was reaching the end of its lifecycle, he move to upgrade to an SOA style including Ajax for the user interface. In 2006, he began seriously looking at Java-based open source products.
"We wanted to use Java for the type of application we were developing," he explained. "We ended up with Spring as the application framework. We were looking for an application server that was J2EE capable."
A conversation with a IBM hardware representative, who supplies Arena with blade servers, led him to contact the IBM Software reps for WebSphere Application Server Community Edition (WAS CE) and Arena selected it after what Larkin describes as a lengthy evaluation. He said he found WAS CE met his criteria for supporting the transition to SOA.
Since November 2006, Arena has been live on the new stack and has been building out SOA implementations with Ajax interfaces. Larkin found the benefits of the technology migration outweighed the costs because the new platform gives him the ability to make use of SOA technologies.
Arena is not yet making full use of the SOA capabilities in the new platform such as the enterprise service bus (ESB), Larkin acknowledges, but the developers are moving in that direction. They have been able to use the SOA approach to provide subscribers with integration between the PLM Web services-based applications and locally installed ERP software at the manufacturing sites.
The user interface is designed for global customers including manufacturers in China and the rest of the Asia-Pacific region. Typical users do not have a high level of IT training, so as Larkin says, "They need it to just work."
With Ajax, Arena has been able to provide a very desktop-like look and feel to the SaaS applications, he said.
"There are drop down menus," Larkin said. "You mouse over things and you get information panels. You get tabs."
When the company opened for business back at the turn of the millennium, he said it was a leap of faith for the founders to believe they could provide a sophisticated enterprise applications in a browser, but the arrival of SOA and Ajax made that SaaS dream a reality, he said.
"At this point, we are able to deliver as rich a functionality in the user interface, as our competitors are able to do with client-installed software," Larkin said.