Abstract:Based on the sparse literature investigating the cost of ERP systems implementation, our research uses data from a survey of Swiss SMEs having implemented ERP in order to test cost drivers. The main innovation is the proposition of an additional classification of cost drivers that focuses on the enterprise itself, rather than on ERP. Particular attention is given to consulting fees as a major factor of implementation cost and a new major cost driver has come to light. "Consultant experience", not previously mentioned as such in literature, appears as an important aspect of ERP implementation cost. Particular attention must be paid to this factor by the ERP implementation project manager.