Qualified includes having the proper training, tools, lubricants, cleaning equipment, alignment jigs and fixtures, etc.
Being competent without any other qualifications is sufficient for making babies, but nothing else.
I am a professionally-trained camera repair tech. I worked as a repair tech full-time for four years,
with experience servicing Rollei's and Compur Shutters. I would definitely not suggest that anyone
try same without proper training, equipment, and documentation.
I still have a fully-equipped camera repair shop, including a huge inventory of replacement parts.