The INVEST Criteria for User Stories

To ensure that User Stories are effective and facilitate agile workflow, the acronym INVEST is commonly used as a guide.

INVEST represents a set of six desirable qualities that help evaluate and improve the quality of a user story.

It was proposed by Bill Wake as a reminder of the characteristics that make a story easier to understand, plan, develop and test within an agile development cycle.

Meeting these criteria is not always 100% possible, but striving to achieve them significantly improves the clarity and manageability of the backlog.

Independent, Negotiable, Valuable, Estimateable, Small, Testable

The INVEST acronym is broken down as follows:

I - Independent: The story should be as self-contained as possible, minimizing dependencies on other stories.

This allows them to be prioritized, developed and delivered with greater flexibility, without being tied to the completion of others.

N - Negotiable: A user story is not a rigid contract, but a starting point for conversation between the Product Owner and the development team.

Details are negotiated and refined through dialogue, allowing different solutions to be explored and ensuring a shared understanding prior to implementation.

V - Valuable: Each story must deliver tangible value to the end user or customer. It must be clear why the functionality is being built and what benefit it provides.

If a story does not provide perceivable value, its existence in the backlog should be questioned.

E - Estimable: The development team should be able to estimate the effort required to complete the story, at least relatively (e.g., using story points).

If a story is too vague or large to be estimated, it needs to be refined or broken down. Estimating helps with planning and understanding the scope.

S - Small / Size-Appropriate: Stories should be small enough to be completed within one iteration (Sprint).

Large stories (often called Epics) are difficult to estimate, plan and test, and delay value delivery. They should be broken down into smaller, more manageable stories.

T - Testable: It must be possible to verify that the story has been completed corre