What is ship integrity, and how does it work?

Solution 1:

I can't find official documentation on this either, but according to this Frontier Forums post and others like it, ship integrity represents general wear and tear on your ship that's independent of hull integrity and module integrity. It has an effect on your hull integrity though, and module performance (reportedly).

• Low ship integrity directly correlates to a drop in hull integrity. When your ship integrity reaches 0%, your hull will effectively be at 70% integrity, even if the hull is fully repaired.
• Low ship integrity may cause modules to malfunction more often, some posts I saw cited a 30% chance.
• Ship integrity repair cost increases exponentially, so at 95% integrity it may cost 10,000 credits, at 90% it may cost 100,000 credits.
• As ship integrity decreases, so does your ship's paintjob quality...

That's literally all the information I could pull together, relegated to just facts mentioned by more than one user, and only stuff that isn't contradictory. I'll edit if I find anything from official or tested sources.

Solution 2:

I cannot answer your question fully, but Integrity used to be called "Wear and Tear".

Basically, as you use your ship, it gets damaged simply through use. My understanding is that when it reaches zero (possibly before) your ship modules will start to take damage and eventually fail. This limits the distance you can travel when exploring, but I've never put it to the test. I don't fancy blowing up in the middle of nowhere and losing a ton of exploration data.

As the integrity reduces, previously you would notice the wear and tear in the appearance of your ship. Recently, due to people who didn't want to pay full repair costs but had paid for ship paint jobs that they wanted to keep looking nice, Frontier separated out the Paint Job as a distinct damage attribute that you can repair cheaply.