methodology to choose vendor of data war

Could you comment the methodology that we are doing the evalaution of selection for the data warehouse vendor?

1. investigation of Business requirements to support executive decision, not for data mart or reporting tool.
2. project team established
3. investigation feedback from user group and network about data warehosue vendors.
3. formulating short list of vendor
4. evaluating and scoring in matrix
5. invitation to vendor
6. evaluation responses from bids.
7. acquisition
8. pilot sheme.

One issue is that we cannot use prototype befoe ITT.