If a rep was selling a bundle of hardware, what type of rule would prevent them from combining it with service for software?

Hello @Atul Sonavne, 

If a sales rep is selling a bundle of hardware and you want to prevent them from combining it with a software service, the best approach would be to use a Constraint Rule—specifically, a validation-type constraint rule. This rule is designed to restrict incompatible product combinations in Salesforce CPQ. In this case, the rule would check if both the hardware bundle and the software service are selected in the same quote, and then block the combination with an appropriate error message. It ensures that reps can’t accidentally or incorrectly bundle products that shouldn’t be sold together. 

I hope this helps. 

Thanks & Regards 

Amit Kumar