What are the costs of tech debt

Any engineer who has been in the field more than a few years, at most, identifies with tech debt.   Tech debt is the technical stuff behind the scenes engineering knows needs to be addressed but has been put aside for now.   Tech debt is good name--something owed to the software stack.

And, it does accumulate interest, like real debt, even if we cannot materialize that costs on the balance sheet.   The longer parts of the system are neglected the more expensive it becomes to maintain and later address. 

And here's lies the real problem with tech debt:  how do you measure its on going costs?  

As long as I have been in this industry, that has been a challenge.  

On going costs are those things like: system performance, additional hosting costs, additional support costs, slower updates to other parts of the system, "random bugs" that just do not seem to go away. etc...

So often, from the business side, if the software works, those questions are not in their minds.  Sure, its slow and its fun to complain about more than anything else.  It's only when their job function is actually impacted does the business move to address it (sorta, but we can talk about that another time).

I wish I could find a way to build meaningful data around tech debt costs.  I do not know if this is something that could be built or created by AI.  Its worth exploring.  

I would love to hear your thoughts.   Once this topic generates enough chatter, I will turn on comments.