If you cannot use ’money’ for measuring software development, then what else is there that would suit you better?
Let us presume that I have a software product and one software development team of ten. We roll out a significant version update four times a year. Updating has to succeed without issues because we have a five-figure number of users.
Critical bugs found during the last two sprints causes us to add one stabilization sprint to the end of our development cycle. It delays shipping and engages the development team for two more weeks than what the original plan was.
If the salary of a developer is 3000€ a month, it would mean approximately 4500€ of expenses to our company for each developer. A team of 10 would then cost 22.500€ per sprint. In addition, it delays the start of the next development cycle and risk of the same scenario occurring again rises.
Every severe wave of client reclamations keeps our support team occupied for days. It usually is work taken away from somewhere else, and it has an impact on our reputation as well. It’s easy to calculate the stacking cost following the same principle as above.
It might not feel like a lot from a budget point of view. But consider routinely going through such scenarios for example 4 times a year. It quickly adds up to six-figure sums of money.
I think money is an excellent metric to consider. And since I’m a tester, I always calculate how much testing we could get with that amount of euros :D
For 100.000€/year you even could get two full-time testers to join your team.
 In Finland where I live, the salary expenses could roughly be multiplied by x1,5 to take into account the taxation and other legistlative responsibilities of an employer.