Hi Diane
This might be caused by couple of reasons. Might be caused by wrong settings in IP30 - Deadline monitoring.
Check IP10 and try to understand the call dates and Order Plan dates. And check the background job which triggers IP30. If the "interval for call objects" is covering a large period, then the system starts generating orders quite in advance. And if these are counter plans, then you better take a look at your current measurement readings. If by mistake (or maybe that's the case), the counter reading is too large, SAP might generate multiple orders.
Cheers
Savas