You are right in that at the end of 6 years, you'd be in middle management.. typically
DSTA staff start at grade 6. If as a scholar you do well, in 4-5 years you would make grade 8 (senior engineer) and would have held the title of "project manager". Note that this title is not taken lightly in
dsta context because it sounds trivial but you bear full responsibility for your project. You would then likely be seconded out (perhaps DrTech or
MINDEF) or rotated within
DSTA (unless of cse you express a strong desire to continue what you are currently doing) for more exposure to upper management (more "tests" for you). The main thing they are looking out for is your ability to make things happen out of your own initiative. Because that's the kind of leadership that they want. (actually what all organisations want)
Ok i have not heard of
DSTA people becoming technical consultants on their own and providing services back to
MINDEF (maybe i havent seen widely enough) though i have heard
DSO people forming their own technical consultancies.. examples are LOOP (RF electronics), Dr Chew Siou Teck (icredo) and Dr Anthony Ng (d-crypt) and provided services back to the defence industry. But note that these people are very very established in their chosen fields, very well-known in the defence circle before striking out on their own. It may sound glamorous having your own consultancy but i've heard its very very tough to survive outside. nobody owes you a living.
again like i mentioned in my previous posts, you take up a scholarship BECAUSE you've already decided to make it your life-long career. Example, a teaching scholarship from
PSC because you've already known early on you really really want to be a teacher or
DSTA scholarship because you want to be an engineer in our defence industry. The scholarship thus makes your original choice sweeter because it gives you a headstart over your peers who want the same thing.
Its NOT the other way around where you become an engineer in the defence industry because because you took up the
DSTA scholarship for watever reasons like: to study overseas, to make your parents proud, to go one up over your non-scholar sibling or whatever.