Methods, systems, and apparatus, including computer program products, for implementing a software architecture design for a software application implementing strategic sourcing. The application is structured as multiple process components interacting with each other through service interfaces, and multiple service operations, each being implemented for a respective process component. The process components include a Purchasing Contract Processing process component, a Supplier Invoicing process component, a Product Catalog Authoring process component, and a Source of Supply Determination process component.