JDE uses Effectivity From and Thru dates to track engineering Change Cut In. Is there any proven way to tie the effectivity to production units without using the effectivy dates. I notice the BOM file F3003 has a effectivy from no. (IXFSER)and effctivity thru no. (IXTSER) fields. Does anyone out there have experiance with using these fields? They don't show up on any screens or reports. Please advise.