The first complex ERP system SEIK ERP system was made to fully support the trading processes. Its modules are: procurement, warehouse management, sale, marketing, transport, finance, controlling, product management, dealing with returned items, filing. We customized the system according to the rationalized company operation. After introducing the system the previous warehouse shortage dropped to 2% (!) of the former shortage, thanks to the systematic data management. The time spent with stock-taking dropped to its fifth. The procurements could be planned so the stock management became significantly more efficient. In accordance with Prosper's professional approach the SEIK system [...]