Tom answer merely shows how long he's been at this, since back in the day when messing around with the open period could completely mess your summary files up. Work Order does not have a period end, and he's right about payroll. Other than that you should have no problem reopening periods. If you reopen ANY module, you need to have GL open to that period (or earlier) as well so that the posting doesn't go to a different period in GL than it does the other module. But if you reopen a period in say, Sales Order or Purchase Order, you're also going to want to make sure that you have AP, AR, and Inventory open to the same period so that anything posted from SO/PO to that period can also go to that period in all modules integrated with them.

When you're done, you should close the periods properly up to the last period you want closed. So for example if you are currently in period 8 in all your modules, and you need to reopen 3 in purchase order, then when you are done, do the period end for 3 in PO, IM, AP, and GL, then do the period end for 4 in PO, IM, AP, and GL.. and so on.

You got called experienced :)

You got called experienced :)