What steps would you follow and what information would you collect to ensure sound data-driven decisions?

Part I

You used the data you collected in order to arrive at the most-informed decisions possible regarding changes to the organization. What steps would you follow and what information would you collect to ensure sound data-driven decisions?

Part II

It is now time to execute the reorganization of Informational Systems. Describe how you would implement the following:
The centralization of Finance and HR (no jobs lost, but increased specialization and responsibility).

The de-centralization of the heretofore separate product departments (break up of existing teams, reforming new teams, and new reporting relationships).