When should the lead time for a packaging machine start?

For customized packaging machinery, lead time does not necessarily start on the contract-signing date. The supplier may need the deposit, final technical approval, product samples, or packaging materials before production can begin. The purchase contract should define the conditions that trigger the lead-time calculation instead of simply stating “60 days after contract.” It is also useful to separate technical approval, design review, sample testing, manufacturing, factory acceptance, and shipment into milestones. This makes it easier to identify where a delay actually occurred.