Compiled ByDeborah Austin Worldwide shipments of warehouse management systems (WMS) software and services will double during the next half-decade -- but grow at a slowing pace -- says ARC Advisory Group's new Warehouse Management Systems Worldwide Outlook. WMS sales exceeded $840 million in 2000 -- growing by almost one-third -- while 1999 sales grew only 4%, reflecting Y2K concerns. Combined, the two years' compound annual growth rate (CAGR) exceeded 17%. For the next five years, as WMS matures, ARC predicts a 14.6% CAGR. The fastest growing revenue stream: Web application hosting (WAH), emerging as a new revenue engine for many WMS companies. Still, by 2005, WAH will only comprise 4% of WMS revenues, says ARC -- up from 1% in 2000. Dedham, Mass.-headquartered ARC is a strategic planning and technology assessment firm.