Using sanity checks in software is normal practice, especially in software that calculates critical things. It works.
> I’d argue
I'm sure if you put some effort into thinking about how to make it work, you'll be successful.
> I’d argue
I'm sure if you put some effort into thinking about how to make it work, you'll be successful.
Literally the whole point, that I've repeated to you 3 times now, is that a single cent is not critical if it means losing the entire order.
This isn't a rockets trajectory or a an MRI scanner, it's a glorified tablet selling high-volume impulse food at a good markup, so stop pretending as if the context doesn't matter when discussing things.
I explained how to deal with that.
BTW, crooks have stolen millions of dollars by adjusting software to shave off a penny here and there. The idea that McDonalds can afford to be unaware of a missing penny in a transaction, when they have billions of those transactions, is wrong.
In accounting software, it's critical to be accurate to the penny. Having the POS software be off by a penny calls into question the entire reliability of the software. Especially when normal accounting controls are not followed and the penny error is not detected.
I once read a story where a prospective engineering hire was given a plant tour at Ford. He noticed an inefficiency that was costing Ford 5 cents per car. He was promptly hired.
Edit:
> rockets trajectory or a an MRI scanner
I've heard the same arguments from people who vigorously insist that it's correct for rockets and scanners for the software to ignore bugs and soldier on. I hope the people who do write that software do not agree with those arguments. I suggest that re-evaluating this merits an investment of your time.
This seems implausible at best, unless it was long enough ago that 5 cents was a meaningful amount of money. Ford only sells about 5.5 million vehicles per year, so even an inefficiency which affects every single vehicle would only cost $280,000 / year, which is almost certainly not an amount that justifies a process change across all ford assembly lines.
It's important to keep in mind what the acceptable margin of error is. It's very easy to say "no discrepancies are acceptable," but in sometimes you have a legacy system that mostly works and it's not worth the person-hours to stamp out every inconsistency.