Lastenhefts

A Lastenheft, often translated as a "requirements specification" or "user requirements document," is a crucial document in the development process, particularly in software engineering and product development. It is created by the client or the future user of a system or product. The Lastenheft describes the overall objectives, requirements, and constraints of the desired solution from the client's perspective. It outlines what the product or system should achieve, the problems it needs to solve, and the desired functionalities and performance characteristics.

The primary purpose of a Lastenheft is to clearly communicate the client's needs to the development team. It serves as a foundation for the subsequent specification of technical details, often referred to as the Pflichtenheft, which is created by the development team based on the Lastenheft. The Lastenheft typically focuses on the "what" – what needs to be done – rather than the "how" – how it will be implemented. It should be comprehensive and unambiguous to minimize misunderstandings and ensure that the final product meets the client's expectations.

Key elements often found in a Lastenheft include functional requirements, non-functional requirements (such as performance, security, usability, and reliability), constraints (like budget, timeline, or existing infrastructure), and acceptance criteria. It is a living document that may be refined and updated throughout the project lifecycle, but it is essential for establishing a shared understanding of the project goals from the outset.