I am in the planning stages of a multiple award IDIQ recompete for a travel management service and am interested in learning about source selection downselect best practices while I wait for Amazon to deliver my newly purchased copy of the Source Selection Answer Book (thanks Vern!). The service is complex and can interface with variety of agency systems as defined and needed by the agency--ERP, financial systems, email, etc. The government's travel market is finite--only so many travel dollars are available each year--but the government's travel rules are many that the service will have to account for (and to make it more complex, agencies have the ability to further tailor some of the rules to suit their needs and service providers will have to meet FISMA requirements). Agencies are interested in choice among service providers, but there isn't enough business to make the effort financially viable among industry providers if several awards are made. Everything I've been able to find on the topic of downselect approaches centers around R&D or construction and I'm hoping to be able to use some best practices around this on my effort. I want to be able to use a phased evaluation approach to get to meet both agency needs for choice and industry needs for ROI (and my needs for an efficient procurement). Any best practices out there?