Workforce diversity has become an essential issue in business. The modification of the personnel structure in companies requires effective diversity management as an integral part of the company. Recognizing and valuing heterogeneity with a view to improving organizational performance is the result of change processes aligning management, employees and co-determination as the representative of employee interests and as an active multiplier for diversity management. There are still specific solutions which have to be found for the operational coordination of equal opportunities and equal treatment on a legal basis. To ensure diversity balance, a relevant question that still remains to be answered is if and to what extent the fair and effective allocation of scarce resources as well as the securing of labor rights can be provided for a diverse workforce given the implementation of core workforces versus non-core workforces and the disturbance of allocative justice inside a company by the increasing number of multiple collective bargaining agreements. In practice emerging conflicting interests require suitable approaches which imply a shifted perspective of co-determination in order to strengthen its role in the company and the change process.