The document describes phases of a research project that aims to develop an assistance system to support age-differentiated work design and employee assignment. Phase 1 involves cross-sectional studies to identify design measures needed to adequately assign current employees regarding performance and strain. Phases 2-3 involve longitudinal studies to identify proactive design measures for an aging workforce and measures for specific workers to prevent disorders or strain. Tool I was developed and validated to assess physical demands and abilities, and initial studies found little dependence between age and disorders but correlations between workload and disorders.