Because of the unreliability of human experts judgements, fuzzy systems are widely applied in decision making problems related to adoption, implementation and maintenance of ERP systems. This paper presents a novel application of the fuzzy Analytical Network Process (ANP) for evaluating ERP post-implementation alternatives. The proposed framework aims at ranking different alternatives to implement a given post-implementation business requirement based on experts perception of implementation effort and risk. Regarding decision criteria, the ANP network considers two levels. At the higher level of abstraction we consider technical effort, organisational effort and long-term risk, whereas at the lower level we consider different strategies for implementing given business objects, functions and processes in an existing ERP system. Decision makers preferences are translated into preference weights using triangular fuzzy numbers. An example is presented to show the application of the proposed framework.