Quality of work and products in enterprises of the future: proceedings of the Annual Spring Conference of the GfA on the occasion of the 50th anniversary of the foundation of the Gesellschaft für Arbeitswissenschaft (GfA) and the XVII Annual Conference of the International Society of Occupational Ergonomics & Safety (ISOES), Munich, Germany, May 7th-9th, 2003: Qualität von Arbeit und Produkt im Unternehmen der Zukunft