In the past, many management systems have been developed. This paper describes a new concept especially suitable for small-and medium-sized enterprises that integrates different kinds of management systems. First of all, requirements for a reference model have been derived. Then, as one objective is to increase acceptance of management systems, employee participation measures have been considered in order to enhance longterm success. Finally, results from a case study in a small construction company in Germany are presented. The integrated management system in the case study is built up in a process-oriented way and considers the standards ISO 9001 (quality), ISO 14001 (environment) and SCC (occupational safety). Several measures to stimulate employee participation are described and evaluated, e.g. vision workshop, CI-circle, use of project groups to identify, visualise and revise work processes.