The objective of this paper was to examine, through a Problem Structuring Methods (PSMs) cognitive map, the possible uncertainties, complexities, and conflicts related to the commitment element, as a consequence of the environmental management adoption, through the implementation of an Environmental Management System (EMS). It was, also, proposed a measurement model of this mentioned behavior to be validated in future studies, in order to measure the commitment of all civil-service employees involved in the new management, before adopting this given system. The commitment to be analyzed through this model is divided into two components: affective and normative. The research was done with 15 managers of a Federal Public Institution, located in the state of S??o Paulo, Brazil, and the data that compose the cognitive map were obtained through a face-to-face interview, from May to November 2015, besides group meetings with the aforementioned managers, from December 2015 to March 2016. The results of the cognitive map analysis demonstrated the necessity to investigate the commitment factor, when there is the intention of adopting the EMS. It was, also, inferred that the suggested model, will be validated in longitudinal studies.