From Mainframe to Client/Server; to Web, what has been changing in        application systems ...?  It's IT technology and environment, not function          requirement itself. ¡@ The cost of system development, from expensive but relatively guaranteed to        success in Mainframe-era to expected low cost but easily lost control in Open-        era. What's wrong...? ¡@ Retain your IT knowledge asset, gain the merit of new technology, you don't          have to jump into revolution. ¡@ Compromise the simple; stable development process in mainframe with ower        cost; Weblication expected in Open environment.        Extract and compromise the merit of Mainframe & Open development. ¡@ An easiest way to successful development of Java Weblication.        We CASE IT with Model & Pattern. ¡@ (WUI)  Web Client Tool --- Rich-Client Function On Thin-Client Environment  ¡@ (AAF) Weblication Access Audit Facility ---                           Auto-Recording; Built-in Query Function; Auto screen version control. ¡@ (Jaffiiss) Java Weblication framework --- Higher productivity; Lower threshold ¡@ (Xup2Jaf) Weblication total solution --- A tool way both in Design and Development  ¡@ Customized Weblication Development Service --- Tooled; Low Cost; High Quality ¡@