To obtain a standardized method for performance capacity assessment in social medicine reference to a generally accepted model of performance capacity is necessary. Further, such a model enables description of the effects of chronic disease on performance capacity. This article describes how the term "performance capacity" can be reduced to operational basal parameters by a hierarchic breakdown, with the domain "physical performance capacity" having the most complex structure. Furthermore the construction of a graduation according to work-load taxonomies for every parameter is shown. The collection of data on the level of basal parameters is essential to assess the concrete performance capacity. To apply the model as a basis for estimating the effects of chronic disease, graduated disease features have to be created. The benefit of the procedure described lies in increased transparency of the decision process. Hence, performance capacity assessment will gain reliability and objectivity.