A data collection system that simulates a transaction processing environment. Instead of updating master files (customers, inventory, etc.) when orders or shipments are initiated, the transactions are stored in the computer. When a user makes a query, the master record from the previous update cycle is retrieved; but before it is displayed, it is updated in memory with any transactions that may affect it. The up-to-date master record is then displayed for the user. At the end of the day or period, the transactions are then actually batch processed against the master file.