At what stage in the development of an R&D project should patient organisations qualify as partners?

There is a general desire for increased involvement of patient organisations in collaborative healthcare projects, as they bring experience, knowledge and real-life assessment to the table. What are the benefits of creating partnerships that cross scientific, academic, advocacy and industry spheres? How early should patient organisations be involved in R&D efforts? How do patient organisations influence the way collaborations are carried? What are the favoured R&D tools involving patients at research scale and what is their acceptance?