I work in purchasing and we have been in discussion with our planning team for as long as I can remember due to component demand being requested or appearing in the MRP outside of lead time and in some cases the schedule releases appearing past due when a week before there was no demand. Outside of a sales order being accepted and placed with a due date that is violating the lead times, what can cause that top assembly demand from a sales order be present but not the component demand for said top assembly? for example our customer service team enters a sales order with 10 month lead time due to the main contributor to that lead time being an 8 month lead time component, what can cause that only until a couple of months prior to the due date the demand for said component with extremely long lead time suddenly appear as a past due schedule release in the MRP?

Thank You for your time and your help.

-Gabriel Camarena