Waterfall

an exaggerated delivery approach based on stage containment between requirement, design, development, and test.

— DevOps for the Modern Enterprise, Mirco Hering

The traditional way to organize IT delivery projects, by dividing them into phases with one phase following another linearly. When represented on a Gantt chart, which it typically was, such a project resembled a waterfall. A waterfall project is carefully planned out in advance, with the requirements defined up front, and a series of milestones planned out to gauge the project’s progress. In general, the IT system was delivered at the end of the project, in a single large delivery. Success in a waterfall project is measured by adherence to the project plan and schedule. Although this is the traditional way to organize IT projects, it has proven to be largely ineffective and has been replaced by Agile delivery approaches.

— War and Peace and IT: Glossary, Mark Schwartz

The traditional development of cyber-physical solutions has been conducted through a serial life cycle flow of design, development, and testing (known as waterfall)

— Industrial DevOps, in “Chapter 1: Toward a Practice of Industrial DevOps”, Dr. Suzette Johnson and Robin Yeman

Specification-driven delivery (also known as waterfall)

— Progressive Delivery, in “Chapter 1: Progressive Delivery”, James Governor, Kim Harrison, Heidi Waterhouse, Adam Zimman

The word “waterfall” is used as there is a sequential, stage-gate process, where work is completed at one stage before flowing to the next stage and so on. It is one-way, with big batches of work passing by job role.

— Sooner Safer Happier, in “Chapter 0: How We Got Here”, Jonathan Smart

traditional sequential “waterfall” methods that emphasize documentation over validated capabilities

— Industrial DevOps Reader's Guide, in the text

The waterfall model—in which a requirements document is created for a project based on the company’s needs at that moment in time and set in stone for the duration of the project

— War and Peace and IT Reader's Guide, in the text

Waterfall is called Waterfall because it's a very traditional approach of software development where you gather requirements, you lock yourself in a room, you work through the problem, and when you get out of the room, you're like, "Hey, this is your solution."

— Tejas Chopra · DevOps at Netflix, Las Vegas 2023 · at 6:13