Waterfall Methodology

Waterfall structures a project as a series of distinct phases that flow downward in one direction, much like a physical waterfall. Each phase produces a defined deliverable (a requirements document, a design spec, a tested build) that gates entry to the next phase. There's little expectation of revisiting earlier phases once they're closed out, which makes planning, budgeting, and scheduling straightforward up front. This rigidity is Waterfall's biggest strength and its biggest weakness. It suits projects with stable, well-understood requirements and heavy compliance or contractual documentation needs — construction, manufacturing, government contracts, and regulated industries still rely on it. But because problems in early assumptions often surface only during testing, late-stage discoveries can be expensive to fix, and Waterfall struggles when a customer's needs are likely to change mid-project. That trade-off is why most modern software and product teams use Agile methodologies instead, which deliver in small iterations and adapt as they go. PMP®-certified project managers are expected to know both: PMI's exam covers predictive (Waterfall-style), agile, and hybrid approaches, and choosing the right one for a given project is a core PM competency covered in CertScope's PMP training.