Which development model is the classic approach to software development?

The Waterfall model is considered the classic and traditional approach to the software development life cycle (SDLC). It is a linear-sequential model where progress flows in one direction, downwards through distinct phases: requirements, design, implementation, verification, and maintenance. Each phase must be fully completed before the next can begin. This rigid, structured methodology was one of the earliest formalized models, making it the foundational or "classic" approach, in contrast to more modern, flexible, and iterative methodologies.

B. Scrum: This is a modern, iterative, and incremental framework within the Agile methodology, not the classic sequential model.

C. Kanban: This is a method for managing workflow, often used in Agile development, that emphasizes continuous delivery and visualizing tasks, not a classic SDLC model.

D. Lean: This is a modern philosophy focused on maximizing value and minimizing waste, which influences Agile practices, rather than being the classic development model itself.

1. Juniper Networks Education Services. (2021). Junos Automation and DevOps (JAUT) Student Guide. Chapter 2: Software Development Methodologies. The guide introduces the Waterfall model as a "traditional software development" method characterized by its "sequential design process."

2. Royce

W. W. (1970). "Managing the Development of Large Software Systems". Proceedings of IEEE WESCON 26 (August): 1–9. This paper is widely cited as the origin of the Waterfall model

describing the sequential phasing that defines this classic approach.

3. Massachusetts Institute of Technology. (2018). 6.033 Computer System Engineering

Spring 2018. MIT OpenCourseWare. Lecture 2: The Software Crisis

and Other Problems. This lecture discusses the historical evolution of software engineering

presenting the Waterfall model as the first major structured process designed to bring order to software development.