A recent article in PRNewswire states:
"The U.S. government is the world's largest consumer of information technology (IT), spending more than $76 billion annually on more than 10,000 different systems – more than $600 billion over the past decade. Fragmentation of systems, poor project execution, and the drag of legacy technology in the federal government have presented barriers to achieving the productivity and performance gains found when technology is deployed effectively in the private sectors."
Done correctly, leveraging enterprise class cloud computing, implementing best practices capabilities for the entire value chain and creating projects that can have cost, time and performance guarantees, the government truly can save not only billions of dollars but significant time which leads to massive improvements in performance and the ability to serve.
The government has identified it needs a true hierarchical database in order to keep data secure. This cannot be done with relational databases and therefore it is not able to achieve the cost savings through multi-tenancy.