Iterative Development Model
The iterative development model builds software through repeated development cycles, refining and improving the product with each iteration.
“A type of software development lifecycle model in which the component or system is developed through a series of repeated cycles.”
(Definition reproduced from the ISTQB Glossary. Copyright belongs to ISTQB.)
View the complete ISTQB GlossaryWhat is Iterative Development Model?
Each iteration produces a working version of the software, allowing feedback and lessons learned to influence future development.
Repeated refinement: Features improve over multiple iterations.
Continuous feedback: User input shapes future development.
Testing impact: Every iteration requires regression and integration testing.
Real World Example
A team builds a customer loyalty points system using an Iterative development model: a short first cycle delivers basic point accrual, the next adds redemption, and a third adds tiered rewards — each cycle producing a working, testable increment.
On a previous project built as one long linear delivery, testers only received the entire loyalty system at once after months of work, and by the time a defect in the basic accrual logic was found, the redemption and tiering features already built on top of it needed rework too.
This time, testers get involved at the end of each short cycle, testing the working increment — accrual first, then redemption, then tiering — as soon as it exists, rather than waiting for every feature to be finished together.
A defect in how points accrue on partial refunds is caught and fixed at the end of the very first cycle, before redemption and tiering are built on top of the same flawed calculation — the fast feedback loop an Iterative development model is structured to provide, and that one big delivery at the end would have delayed for months.
Practice Questions
Question 1
A team delivers a customer loyalty system in short repeated cycles: accrual first, then redemption, then tiered rewards, each producing a working increment. Which development lifecycle model does this describe?
Question 2
What testing benefit does an iterative development model MOST directly provide compared to one large linear delivery at the end?
Test your knowledge with real ISTQB-style questions
You’ve learned Iterative Development Model. Test your understanding with topic-specific questions in our Mock Exams.