"So there were many surprises and many cans of worms that we opened," he says. "We had some budget overruns and we did take longer than we would have hoped - but only because the point of origin was a lot messier than what we had thought."

This was somewhat mitigated by Aeroplan's strategy of breaking the SOA implementation into logical pieces and tackling them one at a time. Once the team understood the potential for the legacy systems to trip them up, it could build in time between implementation projects to scope out the next step and plan how to solve whatever issues presented themselves.

That is indeed the only way to overcome any of the challenges the company faced, Lafrance believes. "If you know ahead of time and brace yourself for something, you can plan accordingly and work at trying to mitigate the impact," he says. "But if you're not ready for it, it's going to take you by surprise and then you're always backpedaling trying to get out of it."

A Different Approach to Data

If there was one thing he could do differently, it would be to "embed the data layer into our SOA a lot sooner," Lafrance says. Aeroplan initially saw SOA as primarily a transactional solution, but data, he now believes, is just as important. Fully integrating the company's vital customer data into the framework has not yet been done. It still resides on an Air Canada mainframe, though a project is now underway to "repatriate" and establish SOA-integrated data systems on resident servers.

Failing to do that earlier in the process, he admits, may mean having to partially redesign services and applications. It would have been better to have hired a data modeler early on and use technology such as the AquaLogic Data Services Platform to integrate the data layer from the start.

"There are two ways to go at SOA," Lafrance says. "With transactions at the centre, or data. I think if data is in the middle, that would result in better designs of services, more effective transport of services and less processing time."

Not that he has any deep regrets. The Aeroplan SOA has already delivered tangible benefits and they will only increase. That's the nature of the beast: once established it pays dividends every time you build a new application or, as in Aeroplan's case, add a new partner.