Before revision: ACM Press - Pearson Educational, London 2002 Development 180px|An example of two components in UML: Checkout processes a customer's order, which requires the other one to bill the credit card.
After revision: ACM Press - Pearson Educational, London 2002 Considerations 180px|An example of two components in UML: Checkout processes a customer's order, which requires the other one to bill the credit card.