The maintenance of a well working informatics infrastructure needs expertise and care. This can be a difficult task for smaller companies. The web based applications – sold as Service as a Services – can be the solutions for this problem.
The cloud platforms are excellent bases for building SaaS's. But we have to rethink the architecture of the regular enterprise applications to fully take advantage of such a system.
We have to serve several tenants with a single application to reduce the load from the number of tenants as much as possible. But we have to allow that several instances of the same application can run concurrently for a well scalable system.
While reaching the above goals we also have to ensure the safety of the tenants' data and keep the high quality of the service. The response times must be as independent as possible from the number of users.
I have examined these problems in a custom application, made with open source Java technologies. From the experience gained from this project, I can conclude that with appropriate design these requirements can be met rather easily.