Last year, at AIS ́98 (Pérez and Rojas, 1998), a series of variables was presented to measure the influence of change management on the effectiveness of the Information Systems development process. This proposal was based on the analysis of possible factors, which affect the Process Effectiveness dimension. The Process Effectiveness dimension is one of the four dimensions included in the Systemic Global Quality vision. The other dimensions included in that vision is: Product Effectiveness, Product Efficiency and Process Efficiency (Callaos and Callaos, 1996). This paper presents the results of a case study performed in a company of the oil- producing sector and is focused on measuring Process Effectiveness in the implementation of three SAP/r3 modules (Sales, Materials and Finance). The results participating in the process in roles such as the Leaders and End Users. No evidence was found on the rest of the showed that there is a correlation between the Change Management factor and Process Effectiveness in the personnel personnel - the technicians and functional users. This research represented a contribution to the organization subject to the study on the improvement of the Process Effectiveness for the development of its Information Systems.