Assembly workload and human labor is the main expense factor during the assembly of products. Here, the hours of work by workmen multiplied with a company-specific factor equal the occurring costs. The assembly planning of single productions or short runs is often based on experience or the method of compare and estimate. In this paper an aproach is presented, in which the assembly planning is put into practice based on engineering 3D CAD models translated in 3D PDF and a preplanned library of work steps. Through connected time values multiplied by frequency and under consideration of assembly difficulties, transparent assembly base-times can be calculated and expectable costs can be estimated. Through connected resources the needed tool-use per workstation can be determined. Furthermore, a connection of product, assembly process and resource is implicitly created by the planning process itself, which machine-readable will provide a lot of potential for future automatisms.