The consistent qualitative assessment, after each applied change, aims not only to analyze the improvement or degradation of the quality of business processes but also to quantify the change impact on the QoS (Quality of Service) behavior. Our work, in this paper, is focused on the change management to assess the qualitative characteristics of business processes. In this respect, a variety of attributes and metrics have recently been proposed to assess the characteristics of the quality of business process models. We propose an overall quality approach which uses a relevant set of business process quality dimensions, characteristics, and metrics. It also proposes to use threshold values in order to evaluate the measurement results. It may facilitate the decision making during the business process evolution and may also help to maintain the high level of service quality.