I'm a head of a lead school for this. I know you have to do a project in another school ( I have 2 Npqh candidates at my school qt the moment) you need 5-20 days out of school for the project. It all happens in school time. If it's anything like the old Npqh it will be totally bloody useless ( although the experience in a different school might be handy ) and just a hoop to jump through to be a head. You need to be 18 months from headship. If you're headship material, chances are the course will teach you bog all except how to speak NCSL in order to pass.