User Story is the place PO gives his ideas about features so that developers are able to know what requirements are. Acceptance tests are these show the most valuable things of the features represented by some specific cases. Usually PO defines them, but not always. Therefore, refining existing acceptance tests – even defining new ones that cover all features of the User Story must be a worth task.
 | |||
| Acceptance test with Given When Then pattern |
If we understand what we are going to do, we can complete it by 50%
I have worked with some members those just start implementing the features one by one and from top to down of the User Story description. Be honest, I am the one used to be. What a risky approach! Because it might meet a case that is very easy to miss requirements or needs to re-work after finding any misunderstood things.I have also worked with some members those accept spending a long time to clarify the User Story. Reading carefully of whole User Story by defining acceptance tests makes us more confident. Having an overview is even more important because it might link to another User Story. And that is really a good way to make the requirements clear. After receiving feedback from PO about updated acceptance tests, it is the appropriate time for implementing if all things are clear.
As a document helps other members easier to do cross-testing
Cross-testing is a task tested by other members - not the one implements the tested feature - in the team. Acceptance tests reduce the time for reading the User Story when doing this task because the pattern "Given When Then" is more readable than the long description. I don't mean reading only acceptance tests is sufficient; of course the person does cross-testing should read whole story carefully.It's useful for approaching the features with BDD practice and focusing on the most valuable customers’ needs
According to acceptance tests, we easily implement the feature with BDD approach (reference to this post to see how I started practicing BDD with "Given When Then" acceptance test pattern). Focusing on what customer needs should be always a good approach.