The papers in this volume are the Application papers presented at ES98, the Eighteenth Annual International Conference of the British Computer Society Specialist Group on Expert Systems, held in Cambridge in December 1998. These papers continue to illustrate the maturity of AI as a commercially viable technology to solve real world problems. AI technology has enabled organisations to solve these problems and gain significant business benefits. This is the sixth volume in the Applications and Innovations in Expert Systems series. The series serves as a key reference as to what can be, and what has been, achieved using AI technology. The Technical Stream papers are published as a companion volume under the title Research and Development in Expert Systems XV.