Several methodologies use group discussion to identify the root causes of the weak performance of a process. These methodologies conceive the process improvements by suggesting modifications to the root causes based on the feelings of the employees. However, these methodologies do not include the positive and negative cause-effect relationships between the process performance and its root causes, nor the mutiple antagonistic process performances desired by the stakeholders. In order to fill this vacuum we suggest the use of models based on system dynamics with coarse functions to avoid the complex modeling of the activities details. These models specify the intensities of the conceived improvements and their systemic impact on the process performance. We apply these models to conceive the organizational improvements of a process of developing microprocessors.