"Ready for a tech takedown? In the red corner, we have the trusted lane-assist, aka rules-based...
Ok, so you've invested a couple of man-years to get your configuration rules working in your current ERP or PLM system. It took a lot of work, and you have over 10,000 rules - some of them really complex. You're really proud of the accomplishment of the team.
You don't always get the result you expect, and then some engineer has to debug for a few hours - but all in all it works.
However, the rules are now in you back-end system - and your sales are still using Excel or some other home-built tool to quote. The quotes never matches what the back-end system has available. Your have a lot of change orders, where you need to come back to the customer with a updated and correted quotes.
So you think, maybe you should buy a CPQ system and re-use the existing rules?
No - don't do that!
Switching system and keeping your rules is not the answer. I'm sorry to say, but your rules probably aren't very good. This is a classic 'sunk cost' bias where just because you spent a lot of money on something - doesn't mean it's good. If you have 10 people digging a hole in the ground for a day, is the hole worth 80 man hours?
You need efficient rules or even better constraints.
One example for a rim and tire:
Read more about constraints here.
These rules or constraint will be correct today, they will be correct tomorrow - because they describe the natural relation between two items in your product portfolio.
Write new rules!
Maybe even re-use them in your back-end system in the future. The complicated and error-prone maintenance will kill your old rules. Don't let them kill your CPQ-system as well.
