CAiSE '91, held at the Norwegian Institute of Technology in May 1991, is the third in a series of conferences on advanced information systems engineering. The call for papers for CAiSE '91 was given a wide international distribution. The programme committee was chosen from very well reputed researchers in the international information systems engineering community, as well as key professionals in European industrial and consultant companies. The number and quality of papers submitted was very satisfactory, and 29 papers were selected for publication in this volume.