The is no Posting button in the Production Order. If you want to post the output and consumption of the production order, you have to post the Production Order Lines line-by-line by clicking on Line --> Production Journal and then post from there.
This is a very big limitation because it causes a lot of trouble to users if they have many production orders to post. Even worse is each production order has many production order lines. For example, a production plant created 50 production orders a day and each production order has 3 production order lines. User need to post 3 times for each production order. Therefore, user need to post 150 times (3 x 50) a day. Imagine how users will response if you asked them to post 150 times a day.
At first, I thought we have no choice but to post it line-by-line because there is no Posting button in Navision production order to post all the lines at once. Thanks to Iain Robertson from Holchem who has pointed out the solution for me. We can actually post all production order lines at once by selecting a blank line from the production order and then click on Line --> Production Journal to open the Production Journal screen. By selecting the blank line instead of a production order line, the Production Journal will displays all components for all the production order lines at once.
Another limitation is Navision has no function to reverse the production order. User has to be extremely careful before posting any production journal because there is no easy way to reverse back. You have to use item journal to do the reversal if you have posted it wrongly. Navision expects users won't make mistakes.