A company that manufactures engine components. In terms of production resources, the company has six plants, including one dedicated to assembly. Manufacturing includes a machining phase, a heat and surface treatment phase, and then the assembly of the sub-assemblies that will be integrated into the engines.

The sales department receives customer orders every day. Given the manufacturing lead times (cycles of 8 to 15 months), customers in a hurry can place priority orders, but at the price of an over-invoicing of 20% of the order. The factories then treat them as a priority. Large customers (more than 10 orders per year) are also given priority.

After a technical control of the ordered articles, the commercial management introduces the order into the computer and obtains in output, the breakdown of the assemblies composed in elementary components which belong to two distinct categories:

- Parts manufactured by the company

- Subcontracted parts

It then prints a list of "in-house" components for the factories and a list of subcontracted components for the company's stock management department for supply. This department also manages the bi-monthly supply of raw materials. The global order is transmitted to the assembly plant, which can finalize the order only after receiving all the required components.

Changes (amendments) to customer orders can be made after the order has been registered, in order to amend :

- The article codes (in the case of a technical evolution of the article),

- Or the other characteristics of the article (deadline, quantity ordered, ...).

The sales department is also in charge of the follow-up of the invoicing. Actual costs are recorded per order received, with management of the number of hours spent (productive hours transmitted by the plants) and the value (purchase price) of raw materials or semi-finished parts from various suppliers (provided by the inventory management department). The invoice is then transmitted to the assembly plant, which also manages the delivery of the order.

Create a business process REA model that represents this enterprise?