The Brigham Integrated Computing System (BICS) provides a broad range of clinical and administrative data-management functions for Brigham and Women's Hospital (BWH), a 720-bed major urban teaching hospital. We describe here the development of an inpatient order-entry system (BICS-OE) which is fully integrated into the BICS clinical environment. BICS-OE uses direct entry of orders by physicians to improve order response time and minimize transcription problems. BICS-OE includes a number of novel features to enhance its acceptance by physician users and its benefit to clinical practice in the hospital. Dual-mode input gives users a choice of full-screen assistance with ordering, or an intelligent text mode which provides rapid entry of orders by direct typing. An automated primary/on-call coverage by direct typing. An automated primary/on-call coverage list directs patient alerts and cosigning requests to the proper physician. Variable order sets allow a large group of orders to be stored and entered rapidly, even when some of the orders may change for different conditions. Multitasking allows the user to check prior orders and labs while concurrently entering new orders. The system permits a wide range of order checking and alerts.