The process starts upon receiving a purchase order.
The details of  the order are then entered into an ERP system.
Then the order is checked for correctness and completeness.
If the order details are not valid, an order update is requested, which needs to be updated in the
ERP system and checked again. This is repeated until the order is valid.
This is followed by checking whether the ordered product is available in the inventory.
If the order is placed on a Friday or weekend, the inventory check shall be delayed until Monday,
as the inventory is updated on every Sunday evening.
If the product is available, it will be obtained from the warehouse.
Otherwise, the materials for the product need to be obtained and the product be manufactured.
Depending on the ordered product, materials from supplier 1 or supplier 2 may be sufficient to
manufacture the product.
In some cases, however, materials from both suppliers are required for the manufacturing.
If the product is not in stock and an error occurred during manufacturing the product, the order
shall be canceled and the obtained materials be
disposed of.
In that case the process must terminate unsuccessfully.
Subsequently, the ordered product is packaged and shipped to the customer.
At the same time, an invoice is sent to the customer, from whom a payment is received later.
Once the product has been shipped successfully and the payment has been received, the order can be
archived.