Use Signavio Event-driven process chain (EPC) to model the business process below:

This is an ordering process, modeled from the perspective of the customer. It starts when a customer company decides to make a purchase of a product from a vendor. The company (the customer) will create a purchase order request and send to the vendor who will send back a confirmation email with total cost and estimated delivery time.

Next, the company continuously check to see if it receives the order. If after one week from the estimated delivery time the company does not receive the order, it will send a reminder to the vendor. If the order is still delayed by one more week after sending the reminder, then the company will cancel the order. [Note: you will need to include loop logics so the company will continuously check if they receive the order]

Once the company receives the order, it will need to verify whether the received order matches the original purchase order. If the verification fails, the company will need to notify the vendor AND the purchasing department simultaneously. Usually the error comes from a delay in delivery. The vendor will correct the error and send the missing items. The company will have to go through the verification process again. Only when the verification succeeds, the company will send the vendor a check to finalize the order.