Circular Reference in Microsoft Dynamics NAV Production Bill of Materials

A client called the other day and said that they were getting an error, “Max Levels in BOM Structure on 50 is too high”, when trying to ‘Certify a Dynamics NAV Production BOM’.

Figure 1 – Error displayed when certifying a production BOM

This is caused by what is known as a circular reference or an item used on itself. When running MRP, the system will be caught in a loop if there is a requirement for Item 1000 that is supplied by Item 1000.

To prevent a circular reference, the certification process checks to see if there is a circular reference and won’t allow the BOM to be Certified if such a reference exists. In this case the problem is easy to see and fix.

Figure 2 – Identifying a circular reference in the BOM

It is a bit more difficult if the circular reference is caused by the item being entered on a lower level subassembly. In this case, I entered Item 1000 on the 1100 Production BOM.

Figure 3 – Circular reference caused when an item is entered in a lower level subassembly

For more information on this or any other Dynamics NAV topic, please contact ArcherPoint.

Read more blogs by Bob Bergman for practical advice on using Microsoft Dynamics NAV.