This is certainly a worthwhile topic. A corollary to it might be to address the plan for after the event is over. I'm sure that all the legal aspects of this have been covered at length a number of times, so I am purposely not addressing them now.
What I'm referring to is "what to do when the cops leave?" Or when you go home afterwards? Of course I'm using a positive survival outcome. An opposite/ negative outcome scenario would have too many variables to address here.
Things I'm thinking of are; repair - securing the compromised door, window, etc., clean-up - you may be faced with a disturbing amount of bodily fluids, biological matter, etc.; those there in an official capacity do not typically help with clean-up (I used to try, but some stuff involves more that picking-/ scraping-up); psychological aftercare; PTSD is a very real consequence of a near-death or deadly force situation - even if you win. Most police departments have tons of resources for the officer involved in such a situation, plus the officer is usually provided with them at the department's expense. Would your insurance policy help with this? Would your family doctor be able to provide you with the referrals necessary? Then, multiply this times the number of family members involved - especially the kids.
Unfortunately, many deadly force encounters are dynamic, and aren't as cut and dried as we'd expect them to be. Often the person with the least immediate comprehension of what happened is the "good guy" who had to pull the trigger.
I think that many people stop planning once the bad guy's been vanquished, the cops shake your hand, and you ride off into the sunset. However, much of this basic stuff requires immediate action, and adding it into your defensive scenario might be helpful in the unfortunate event you are forced to use deadly force ... thanks