cogm and cogs in ck13n

Dear community,

1 I see in ck13n where cogm = cogs so that credit (dr inventory cr cogm during fg is done) and debit (cr inventory dr cogs during pgi) able to set off complete OR cr cogm set off with actual consumption (material/labour/etc).

2 why cogm = cogs?

3 The only difference of cogs from cogm is the admin/sales overhead which maintain via VK13?

Thanks