Enterprise Resource Planning (ERP) system has been defined as a configurable Commercial Off-The-Shelf (COTS) system integrated into multiple business functions. For most companies, adopting ERP has become necessary to maintain market competitiveness. However, ERP implementation is still critical because project success depends on multiple parameters and involves several stakeholders. This article deals with the Fit-Gap analysis stage, which is an essential step in ERP implementation. This study was carried out through a literature review and interviews with experts to gather information and support stakeholders toward a successful Fit-Gap phase. It presents a set of recommendations for clients and consultants to consider before starting the Fit-Gap Analysis phase, and it presents an approach, with a decision support model represented as Business Process Modelling Notation (BPMN) based on several parameters to be used during the Fit-Gap Analysis stage to bridge gaps. The results obtained are intended for clients and consultants to make the most rational decision to bridge gaps based on the recommendations found, the approach and the decision support models presented.