Abstract Paper aims The first aim is methodological, by developing a conceptual model to describe the internal relationship environment (IRE), the critical factors that impact this environment, the characterization of the parties involved, and their relationships. The second is practical and instrumentalizes the model to measure the effect of differences perceived by internal customers. Originality Distinct works focus on the formulation of management systems, successful implementation, or external and market environmental factors, although there is a lack of studies that relate organizational performance to differences in perceived quality between the parties. Research method The methodology followed a flow of collection/analysis, of the informational data of the company, sketch of the model and flow of information, exploratory focus group, thematic analysis of content, and confirmatory focus group. Then, the procedure of operationalization of the model. Main findings The conceptual model and its instrumentalization describe the apparent relationships between the support team and the operations teams, the underlying relationships of the ERI with the company's management model, and organizational performance. Implications for theory and practice In practice, the proposed measurement instrument allows evaluation of the effects of differences in the perceived quality of internal customers.