Cannot delete SC item

Hi,

We are upgrading from SRM5.0 to SRM7.0.

I have a question about "Operation of PO cancel".

In SRM 5.0, Step of PO cancel is following.

1: Delete PO item(not header delete)

2: Close RFx

3: Delete SC item(not header delete)

But in SRM 7.0, we cannot delete SC item.

So when we delete PO, the SC remain in spite of it no longer update.

Is the behavior we cannot delete SC item which status is "RFx or PO created" system bug?

Otherwise, how can I delete(or complete) that kind of SC?

Please help.

Regards,

Ryo