found a very interesting post on why reference check should be an important aspect rather than just awarding project on basis of other project/contract award letters etc. This post covers questions which could be asked to possible referees.
1. What is the nature of your business?
2. What were your reasons behind <insert the nature of the problem/solution here>?
3. What type of selection process did you employ – RFP, sole source, etc.?
4. Which other vendors did you consider?
5. Why was <vendor name> chosen?
6. What did you find out after you started working with <vendor name> that you wished you knew in advance?
7. What changes in costs/pricing/resources did you experience?
8. If we were to go with <vendor name>, what recommendations would you give to ensure a successful engagement?
9. What has the impact been since <rolling out the solution>?
10. Is there anything that I didn’t ask that I should have?
11. Would you recommend <vendor name> to use based on what you know now?
For more reason on what can be achieved by the question please do visit the post at following link.