The Decommission survival map:
I set up sentry guns facing out the doorway of the room in the top left of the map, and claymores on the back stairs to that room, like this:
Most of the enemies during normal and helicopter waves come along the red arrows, and the claymores take care of the back stairs fairly well. I sit at the blue/red circle with the pillars for cover, and the sentry guns do a decent job thinning out the enemies at the doorway. For juggernaut waves it's the same looping strategy as on any other map. The houses between the air support and the equipment armories work pretty well since there is more cover and more ins-and-outs there.
Decommission is a Tier 2 map.
Jugg waves: 9, 12, 18, 21, 27, 33, 39, 45
Helo waves: 6, 15, 24, 30, 36, 42