Mass Cancel of Requisition Year End

 Good day

Kindly advise

We making use of encumbrance accounting, a commitment is raised when a purchase requisition are created and obligation when PO created. My question is if we do year end must we run the Mass cancellation program for requisitions that was already approved and created into Purchase Orders. I am not sure if this step is really required as when the Purchase requisition is created into a PO the commitment is reverse for it. What is the purpose for running the mass cancellation for approved Purchase requisition and Purchase orders.

Regards