Physiotherapists and occupational therapists mastering spasticity assessment techniques Modified Ashworth Scale (MAS) and Tardieu Scale based on self-experiences starting from a young novice therapists during their clinical practice in year three undergraduate therapists school. Thus, we have developed an upper limb spasticity part-task trainer to increase the frequency of the novice therapist training as an education tool and licensed therapists as well in order to improve raters'variability in spasticity assessment by repetitively simulate spasticity symptoms through upper limb spasticity part-task trainer. This paper present a model-based system engineering using specification techniques CONSENSTM as a framework to guides the development team in optimizing the different process and the diverse specialization of the members.