1) Login to Manufacturing component and go to "Bill Of Materials" screen.
2) Now go to "Manufacturing Rules" screen.
Here a form for creating/updating manufacturing rule is available. System generated Rule Id is used when we create a new rule, so no need to display it at the time of creation. Rule Id should only be displayed in case of editing.
One more reason to hide this at the time of creation is when we submit the form (target=AddProductManufacturingRule) without the required parameter needed for the underline service. It returns error that the required parameter is missing, which is good but the form target get changed to "UpdateProductManufacturingRule" though we are still creating a rule not updating it.