For this achievement, develop all the ship upgrades and keep every character loyal to Shepherd.

The crew can die and you'll still get the achievement. Just none of your teammates can die.

Only the Doc lived for me for the crew, and I still got the achievement. I don't know why people are having problems. This one is pretty easy to get if you remember to:

1.) Remain a fully dedicated paragon or renegade.

2.) Always have full team loyalty. Just do all of their side missions.

3.) Have full/all/maximum ship upgrades. Take time out and do the mining.

4.) Get all the prototype upgrades.

5.) For the assault, use this configuration. I'll list all people you can use, and also who I used:

Tech Specialist
* Tali
* Legion
(I used Tali since recruiting Legion is a Paragon action and I didn't have him)

Leadership
* Miranda
* Jacob
* Garrus
(I used Miranda both times to lead the second team)

Biotic Specialist
* Samara / Morinth
* Jack
(I used Jack)

Crew Escort
* Any loyal character
(I used Grunt)

The team you bring with you to fight doesn't matter as long as they're loyal to you. I used Mordin and Thane for my team the entire time. And Mordin and Jacob for the boss (because I miss selected Thane). Got the achievement first try.

Good luck!