SaaS is just one option for cloud computing

Organizations which are keen to move some applications onto cloud computing have a number of choices.

Software as a service (SaaS) is just one possibility, but rehosting on infrastructure as a service (IaaS), refactoring for platform as a service (PaaS), revising for IaaS or PaaS or rebuilding on PaaS are valid alternatives, according to Gartner.

The firm's research director Richard Watson commented: "When the CIO issues the simple directive: "Move some applications to the cloud’, architects face bewildering choices about how to do this, and their decision must consider an organization's requirements, evaluation criteria, and architecture principles."

He added that all of the alternatives require architects to "understand application migration from multiple perspectives and criteria, such as IT staff skills, the value of existing investments, and application architecture".

If people opt to replace with SaaS, they can benefit from avoiding investment in mobilizing a development team if business requirements are likely to change quickly.

However, they will need to increase their focus on data semantics, vendor lock-in and data access issues, the IT group advised.