Sequential Development Model
A sequential development model is a software development approach in which project phases are completed one after another with minimal overlap.
“A type of software development lifecycle model in which a complete system is developed in a linear way of several discrete and successive phases with no overlap between them.”
(Definition reproduced from the ISTQB Glossary. Copyright belongs to ISTQB.)
View the complete ISTQB GlossaryWhat is Sequential Development Model?
Each phase must be completed before the next begins, making planning predictable but reducing flexibility when requirements change.
Linear progression: Activities follow a fixed sequence.
Clear milestones: Each phase has defined deliverables.
Limited flexibility: Changes become more expensive later in the project.
Real World Example
A regulated product team is preparing a release where Sequential development model appears in reviews, test design conversations, or defect triage rather than as an isolated glossary word.
The risk is that the team treats Sequential development model as interchangeable with nearby ISTQB terms. That makes test scope blurry and can lead to weak evidence for the release decision.
The tester anchors the discussion in the official definition, asks where the concept appears in the product, and designs examples that show the difference between Sequential development model and similar ideas.
The page becomes useful in practice because Sequential development model is connected to a specific testing decision, not memorized as a detached definition.
Practice Questions
Question 1
Which statement BEST describes Sequential development model in the context of ISTQB terminology?
Question 2
A tester needs to explain Sequential development model to a non‑technical stakeholder. Which approach is MOST appropriate?
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