An important part of the Enterprise Resource Planning (ERP) system implementation process is the decision, which modules are implemented and in which order. We posit that the decision of the module sequencing involves a myriad of issues, such as, investment costs and risks, key business requirements and solution constraints. We develop and test an ANP (Analytic Network Process) model to support the sequencing decision. Through the ANP analysis a preferred module implementation sequence is achieved in the case company. Moreover, the practical applicability of the method is discussed in the paper.