In SaaS businesses that sell B2B, I find a very useful approach to buying committee mapping is to get hold of the Opportunity Data and then during the various stages of the opportunity there is usually a bunch of emails; calls and meetings that take place. Most opportunities in the CRM have 1 or 2 contacts attached but the emails; calls and meetings reveal a lot more of the picture. If you can get your hands on that data then you can build pretty comprehensive decision maker maps and show how it changes throughout the sales cycle...
