FactsVSM is a PDA application for van salespeople that allows them to perform tasks like adding customers, creating sales invoices and returns, and printing receipts directly from their mobile device. It syncs transaction data in real-time from the PDA to a back-office ERP system via web services. Each van is set up as a location in the ERP, and van drivers are given user accounts to access transaction forms with location codes as suffixes. The application provides functions for checking stock balances, receipts, and other essential sales and accounting tasks while on the road.