Children with autism have varying degrees of difficulty in their ability to find their way through time and space. This can sometimes prevent students from accessing certain kinds of learning and can therefore stop them from performing some learning tasks because the cognitive load makes it difficult for these subjects to manage themselves. The objective of this research is to understand how a digital planning tool can reduce this cognitive overload. However, it is difficult to measure cognitive overload when working with non-verbal children who have Autism Spectrum Disorder (ASD). In the study described in this article, the dependent variable measured was the cognitive availability of students during learning activities. Our hybrid methodology allowed us to combine qualitative (semi-structured interviews with professionals) and quantitative (filmed workshops with a child and an educator) analyses. Statistical analyses based on the quantitative data did detect any significant evolution in cognitive availability over the period of the study. However, thematic analyses of qualitative data underline the value of this digital planning tool for students in developing their cognitive availability, particularly their autonomy in various different learning activities.