In the power-plant erection the requirements on mechanical assembly projects get more and more challenging. The tender deadlines become more briefly, just the lead time for the erection. The economic success of a project is based on the assembly planning. Significant parameters are the assembly equipment and resource use. Main task is the analysis and evaluation of the assembly planning and the assembly calculation at the company FMT Industrieservice GmbH. Further the conception of a guideline for prospective power-plant projects is planed as well as the implementation of a database. As result of the analysis of different assembly calculation diverse parallelisms could be lifted up and assigned to the individual assembly sections in form of reference values. Based on the analysis the assembly planning process was defined and the individual process phases distinguished. The evaluation of the assembly projects has shown that the assembly planning can be treated in assembly calculation at every project after the same schedule like even in the preparatory phase. Instructions for the internal knowledge transfer could be implemented successfully by means of the defined processing steps and their activities. A standardization of the assembly calculation could be obtained and the transmission delays of the bid phase reduced. This work established the basis for a focused database. Nevertheless more detailed datas are required. The realization of a database is done by a internal workgroup.