Our MatchMerge Vaccine Forecast Decision Support Service (VF-DSS) is a standalone web service arising from more than a decade of development and use by Immunization Information Systems (IISs, or Immunization Registries).  VF-DSS:

• validates a patient's immunization history against a set of clinically-accepted rules; and
• recommends next doses against those rules.

 The validation part of VF-DSS numbers doses (or marks them as invalid, boosters, etc.) as shown in this Interoperability Showcase browser screen developed by the University of Washington:

The forecast portion recommends next doses.