The increasing adoption of ERP systems, in particular, open source systems implemented in SMEs continues to merit research because of their relevance. Although the use of ERP systems in SMEs is in percentage terms smaller than in large enterprises, the adoption of such open source systems represents a great opportunity for SMEs. This article presents an investigation that sought to clarify the rationale underlying the adoption of open source ERP solutions through the case study of three Odoo ERP implementers in Portugal. It was clarified that, although acting in the same market, one of these companies tended to adopt a value-driven business model and the others a cost-driven model. Finally, a methodological proposal is made for the positioning of implementing companies in a strategic quadrant, exemplified by the three cases studied. Future virtues and opportunities of the proposed strategic framework are discussed at the end.