In combat, there should be a % chance that modules are permanently destroyed. Shield modules should be at risk when taking shield damage. When taking armor damage, critical hits should have the possibility to destroy nearly anything on the ship: weapons, armor plates, even the damage control unit. When taking hull damage, the possibility of a critical hit should increase, with the possibility that cargo is destroyed.
This would improve the economy by generating more consumption, and it would make fleet engagements more interesting as ships begin to take damage which cannot be repaired without refitting.