This paper presents a novel method to evaluate the maturity of projects and organizations in order to minimize the risks. It is assumed that the higher the project management maturity (PMM) level is, the higher the performance of projects is, but a high PMM level requires investment. So far, the maturity of the major stakeholders to ensure they have enough competence to perform successfully, project complexity and success have not been considered by maturity evaluation methods. in this paper we go a step forward and investigate the relationship between those elements. As a result of this research, we present a novel model to evaluate the maturity of the Client and the Contractor and the complexity of the projects.. We have applied our model in qualitative research studies and demonstrate that it is a concise and useful framework for companies that seek optimum maturity levels. Our method is useful when the trust among organizations is low, and it provides stronger position to organizations facing a business opportunity.