An ideal cloud-based application is a brand-new business-to-consumer application--"those things we hope will go viral, but we aren't quite sure if they will or not," Edwards says. Manpower doesn't mind paying a per-hour rate in return for that unpredictable capacity. "Certainly for prototypes and proof of concept, we'll look to target as many of those to an elastic cloud as possible," Edwards says. He tells his IT team, "Let's get comfortable with 'Why wouldn't we do that in an elastic environment?'"

But if that app's a long-term hit, Edwards thinks it usually will make sense to bring that in-house. Manpower runs data centers in co-location facilities, with its own staff running some of the operation and an outsourcer running other parts. With that view, infrastructure-as-a-service just becomes a new end point along the outsourcing spectrum, seen as higher-priced variable capacity needed at launch, before moving to a more conventional outsourcing or in-house model at a lower long-term cost once the app is at a large but more predictable scale.

Cloud In The Budget Process

Last year, Manpower considered SaaS on a case-by-case basis as needs arose--such as implementing Salesforce for CRM. But there wasn't a guiding strategy for how and when to consider cloud. As the IT team did due diligence for those projects, it built a list of characteristics that help determine if a project or application makes sense for SaaS or cloud infrastructure.

This June, as Manpower starts its annual budgeting and planning process, it'll have a different approach to cloud. "This planning cycle, now that we have the guidelines of what makes sense from a cloud perspective or not, we'll start targeting specific pieces and go out and see if there's a cloud solution for this," Edwards says. "We didn't do that last year."

Here are some of the filters that will steer projects toward or away from cloud computing.