Increasing competition is compelling companies operating chemical production plant to focus on the their core competence and to entrust other companies with non-core activities. The out-sourcer takes particular responsibility for the selection, instruction, coordination, and monitoring of the external company. The rules applicable to all companies operating at the Marl Chemical Park are laid down in a general handbook for outsourcing management. This handbook describes the tasks and areas of responsibility of participating companies for overall order fulfilment with due attention of existing demands on industrial safety. The resulting obligations for the external companies are given in a set of guidelines for contractors and are an integral part of contracts awarded to external companies. External company management is a means of achieving quality assurance, accident prevention, and improved collaboration with external companies.