Methods, systems, and apparatus, including computer program products, for implementing a software architecture design for a software application implementing time recording. The application is structured as multiple process components interacting with each other through service interfaces, and multiple service interface operations, each being implemented for a respective process component. The process components include a Project Processing component that is responsible for structuring, planning, and executing measures or projects, a Time and Labor Management process component that supports the definition of employees' planned working time as well as the recording or the actual working times and absences, an Accounting process component that records relevant business transactions, and a Goods and Service Acknowledgement process component that includes the Goods and Service Acknowledgement business object, which is a document that states the recipient's obligation to pay the supplier for goods received or services rendered.