All activities, plans and techniques of process improvement show dramatic and positive effects on performance and achievement of results of processes, but, unfortunately, in the next stages and in a short period of time, and as a result of non-sustainability and revocation of the improved processes, they decline and even may reach to a level lower than the initial one. The main objective of the study is recognizing the factors leading to sustainability of the improved processes. To accomplish the goal, some sustainability factors were studied and analyzed using Multiple Attribute Decision Making (MADM) models and manufacturing and operational processes in some elite Iranian organizations as statistical society. Enabler factors of sustainability during execution of improvement plans can lead to initiation and maintaining of the processes in a continuous improvement cycle. There are two main questions in the study as follows: What factors lead sustainability of process improvement. In addition, what is the weight and effect of each factor on success of improvement plans. To answer the above questions, analyses resulted from measurement of sustainability of process improvements and the "test of existence of enabling factors", as an output of this article, make a clear grouping of sustainability factors in a three dimensional model of organizations. Based on the results of the study, the most important and effective factors in sustainability of processes will be included in the process dimension (aspect) of organization. In fact, the total weight of the process dimension factors is more than the people, organizational behavior, strategy and leadership dimensions. "The top management commitment to improvement", as one of the factors included in the organizational dimension of leadership and strategy, is considered as the most effective variable by experts. Meanwhile, the second, third and forth level factors, that is, "standardization and documentation of process", process monitoring (visual control) " and "a formal system of recording of problems", are all included in the process dimension. Moreover, based on the results of the study, the importance rating assigned by nine Iranian experts to these factors, show the relative importance of the process dimension from their point of view.