A COLLECTION OF 30 INFLUENTIAL ARTICLES PUBLISHED
IN EJOR CELEBRATING THE 30TH ANNIVERSARY OF EURO

AN EDITORIAL

Alan Mercer, Lorenzo Peccati, Roman Słowiński, Jacques Teghem,
Bernhard Tilanus, Jyrki Wallenius, Hans-Jürgen Zimmermann

In 2005, the European Association of Operational Research Societies (EURO) celebrates its 30th anniversary. At the time of EURO’s inception, Operational Research methods already had widespread application and success in many areas of business, industry and government, and their use was increasing rapidly. The European Journal of Operational Research (EJOR), founded shortly after, was intended to strengthen those advances by publishing high-quality papers, which contributed to the methodology and practice of decision making, within and beyond Europe.

EJOR was founded on 2 October 1975 and the first issue appeared in 1977. The founding editors were Alan Mercer, Bernhard Tilanus and Hans-Jürgen Zimmermann. The journal, edited by them until 1999, grew to twenty four issues and 5400 pages per year. In years 1999–2004, the editors were Roman Słowiński, Jacques Teghem and Jyrki Wallenius. In 2005, Jyrki Wallenius was succeeded by Lorenzo Peccati. All this time, EJOR was gaining in popularity and importance, so that in 2004, its total number of cites was the second largest amongst Operational Research and Management Science journals. With its 9000 pages of published papers per year, EJOR is presently by far the largest Operational Research journal in the world.

With the present special issue, the past and present editors of EJOR wish to contribute to the celebration of the 30th anniversary of EURO. A key idea of this special issue is a selection of 30 “influential” articles published in EJOR since its beginning.

As a prime measure of “influence”, we considered the number of citations of a particular article since its publication (realizing the weaknesses of using citation statistics as a measure of influence). In order to give more or less equal chance to articles published over an almost thirty year time span, we considered citation statistics for articles published within 5-year time windows. The time windows were: 1977–1980, 1981–1985, 1986–1990, 1991–1995, 1996–2000, and 2001–2005. The citation statistics were obtained from two sources:

• SCOPUS database by Elsevier,
• Science Citation Index by the Institute of Scientific Information (ISI).

As said, our selection largely follows citation statistics. In some cases we used our subjective judgment. For example, some bibliographical surveys and papers providing benchmark datasets were not considered. Another secondary selection criterion was our desire to provide a balanced coverage of different subjects. Inevitably the use of citation statistics militates against the inclusion of recently published papers.

The resulting list of 30 influential EJOR articles is presented below in chronological order. It consists of both regular research papers and review papers. The articles represent various subject areas, in particular: Data Envelopment Analysis, Combinatorial Problems, Multiple-Criteria Decision Support, Managing Uncertainty in Decision Problems, Manufacturing and Logistics, Sequencing and Scheduling, and Metaheuristics.

Significant research and review papers have been published in EJOR in each of these areas. Note, however, that EJOR is publishing significant work in other subject areas as well, the importance of which changes over time.

A celebration is certainly a time for recognising past achievements but also one for addressing the challenges of the future, so that EJOR continues to be one of the world's leading, general purpose OR journals. Time and again, the Editors have been counselled to maintain EJOR's European roots and traditions, whilst welcoming submissions globally and benefiting from the advice of an Editorial Board and referees, drawn from across the world. They will continue to work as a team and to communicate directly with authors and referees, so that they are better able to influence the direction of OR and also to preserve academic integrity.

The Editors will provide sympathetic consideration for papers in new fields and will expedite their publication, in order to encourage operational researchers, especially academics with the freedom to choose their research, to switch areas. HIV/Aids and climate change make newspaper headlines but there are many other vital problems in the life and environmental sciences areas. Rapid changes in ICT are leading to new ways of conducting business, electronic auctions being a familiar example, that need to be reflected better in the OR literature. EJOR also wishes to encourage papers that bring together ideas from different streams of OR. For instance, OR modelling of the logistics chain has been revolutionised but where are the healthcare delivery papers, which take advantage of ICT developments and intelligent decision support to consider the patient from diagnosis to complete recovery? Invited reviews and feature issues, limited to well-defined topics of high current interest, continue to be of crucial importance in developing OR, and the Editors wish to hear from and of potential contributors. They are also eager to publish short papers, which describe successful applications and set out their practical benefits, and position papers, that discuss the present and future of OR.

EJOR owes its success to its Editorial Board, authors, referees and readers, all of whom are thanked most sincerely. For their part, the Editors have always been outward looking and open to new ideas. They welcome suggestions from the distinguished and recently qualified doctoral candidate, alike, so do make contact.