Ask for a Demonstration
During the selection process you should ask for a demonstration of the proposed offering from each of the preferred suppliers. This gives you the opportunity to evaluate the system being proposed and the supplier.
Do you feel comfortable?
Invite the potential suppliers to visit your company. Do they understand your business needs and have experience of your industry? Do you feel comfortable dealing with them? Make sure they offer a regular strategy meeting so that you can discuss with them the needs of your business and what IT solution will meet those needs.