Perils of Legacy Design Description in an Increasing Agile World

摘要

Producing design documentation is a fact of life for systems and software development. But why is this documentation generated? And how much documentation is enough? If you query project managers, the response is likely to be contractual/regulatory requirements to the former and a verbose 20th century template to the latter. Ask software developers the same questions and you'll likely elicit a litany of tirades not suited for publication. There must be a better reason to allocate significant resources to something that is often a source of aggravation and typically relegated to shelfware. The United States Citizenship and Immigration Services (USCIS), a Department of Homeland Security component at the forefront of the Agile and DevOps movement in the federal space, has embarked on a concerted effort to address these and other issues impacting post-legacy SDLC environments. The agency is committed to employing Lean Architecture, Lean Software Engineering and Lean Manufacturing techniques across the enterprise to ensure that maximum benefit is derived from its Agile and DevOps investments. This commitment includes a "Three Bears" approach to system and software documentation: not too little, not too much, but just enough. This paper describes a broad Voice-of-the-Customer effort conducted by USCIS that resulted in an innovative paradigm shift to documenting software design; one grounded in Lean principles and Systems Thinking concepts that exceeded the expectations of most ardent Agile practitioners while satisfying applicable regulations.