Questions about WIP - Outside Processing

Hi,

I have some questions about WIP and Outside Processing. It would be good to know if there are solutions for them ;

-There are 3 sequences for the discrete job namley 10, 20, 40. 20 is for the outside processing. Let`s say the company will produce the 20th sequence instead of using a supplier. Is it possible to cancel the purchase order and skip the WIP ?

- Can WIP be cancelled when there is an open purchase order ?

- When the date of the purchase order is changed, how can it be seen in the WIP?

regards,

Armagan