The idea behind the series of volumes Advances in Petri Nets is to present to the general computer science community recent results which are the most representative and significant for the development in this area. The main source for the papers for "Advances" are the annual "European Workshops on Applications and Theory of Petri Nets"; the "best" papers from the latest workshops are considered for the series, i.e. they are reviewed again and revised or extended accordingly. In addition to the workshop papers, the "Advances" also present invited papers submitted directly for publication. The present volume Advances in Petri Nets 1988 covers the 8th "European Workshop on Applications and Theory of Petri Nets" held in Zaragoza, Spain in June 1987. It also contains a survey on decidability questions for classes of FIFO nets by A. Finkel and L.E. Rosier.