As economies of scale improve, vendor lock-in issues are increasingly cumbersome. In IaaS environments, since the client maintains complete control of the software layers deployed on the provider's servers, it should be a straightforward exercise to migrate those virtual environments. However, the migration of an enterprise's financial systems running in a SaaS environment presents a substantial challenge. Nevertheless, it is important to note that this disadvantage of SaaS stickiness is no more onerous that the stickiness of equivalent on-premise solutions. Therefore, the vendor-lock-in spectrum should not be considered either an advantage for IaaS or disadvantage for SaaS based on their cloud nature.
Cloud Computing's Systems-Integration Challenges
Systems integration has always been a challenge for IT organizations. A proper implementation of a cloud solution should neither ease nor exacerbate this challenge. For IaaS, the burden on IT is to implement a hybrid cloud. That is, by implementing virtual environments on premise similar to the cloud provider's, the integration of systems should be handled similarly to traditional integration tasks.
For enterprises prepared to commit to a single development platform, PaaS solutions offer streamlined integration within the offered platform; however, integrating those systems with others involves not only traditional integration challenges, but also new ones involving the transformations between the on-premise and cloud environments.
With SaaS solutions, the cloud provider wholly controls each system. In some cases, they cannot be integrated with others at all. But, increasingly, SaaS providers are offering application programmer interfaces to enable integration. At a minimum, CIOs should insist on identity integration capability so that SaaS and on-premise systems can share single-sign-on features.