Nexus maturity model, which is created as a structured gradual guideline for the companies wishing to adopt Nexus framework, is a new model, so the main purpose of this paper is to assess the model. Moreover, to explore pros and cons of the model to enlighten the researchers and implementers in the industry is aimed. Two case studies were conducted to collect data and to test three hypotheses. The second case study was executed 4 months later than the first case study which was completed with the same Nexus team members at the same company. During the case studies, structured interview technique was used via face-to-face meetings. Firstly, the results of the case studies show that this model can be applied easily by using the metrics to measure the success percentages of Nexus practices. Secondly, the practices with the low achievement percentage can be determined, the improvement strategies can be defined by means of the goals, objectives, practices of the model and investigation of the reasons as well. Lastly, with application of the improvement strategies, Nexus adoption success can be improved for higher levels by tracking Nexus maturity model elements. This paper presents the first application of Nexus maturity model in the industry, and also the first study to assess the model with its pros and cons in the literature.