2. Listen to your customers

Needs analysis is an obvious step in any design process, but it is particularly important in the case of a product designed for people with disabilities. The first point on which you need to focus is the identification of your users: in addition to disabled people themselves, you also need to consider the needs of caregivers (family, carers, etc.) who are also users of your future product. For example, the caregiver who installs a motor-impaired person in his or her wheelchair on a daily basis, who sometimes pushes the wheelchair and provides routine maintenance, is also an indirect user of the wheelchair. Ask these caregivers, and they'll give you valuable information about their own needs and those of the disabled person.

The second point to consider carefully is how to identify the needs of your main users, people with disabilities. This step is often problematic,...