Blog: Requirements and Gherkin

We have been kicking off our ePRO study (more on this study later) and there are a range of partners in the study. We needed to quickly progress to a level of detail in requirements to ensure common ground even before we get IP and ethics in place.

For this work, I have chosen to use Gherkin, trying to drive some behaviour driven development (BDD). We are not expecting that we will use Gherkin throughout the development — each of the partners has their own methods and tooling and Gherkin / Cucumber is not used. Gherkin does provide a clear and accessible convention to structure requirements as features and scenarios.

Further, as domain specific languages are becoming a popular topic in our lab, it seems fitting to use another one for requirements.

Gherkin Materials

For those not familiar with Gherkin, several people have written about it better than I could here. For example:

• The source on GitHub: https://github.com/cucumber/cucumber/wiki/Gherkin
• Cucumber.io: https://cucumber.io/docs/reference
• Behat has a great description with solid examples: http://docs.behat.org/en/v2.5/guides/1.gherkin.html
• And there is the cucumber book: https://media.pragprog.com/titles/hwcuc/gherkin.pdf

Gherkin and ePRO

We have completed several drafts of the requirements iterating with our partners. The requirements have grown from a half dozen high-level features to 20 pages of more detailed features and scenarios. We have found it useful to organize the features around several actors and the partner / data streams. This works well, given how the project is structured as well as how the ePRO intervention was conceptualized. These requirements now include details such as example data to help the team members. Gherkin’s structure was well suited for this kind of work and the organization by actor was definitely useful.

Gherkin: Business Readable? Business Writable?

I appreciated a post from Martin Fowler reflecting if domain specific languages should be business readable or business writable. In our project, so far, it has been used in a business readable manner. That is, I have been the primary author and I invited comments from the team. Business owners are providing feedback, questions, changes, and notice areas where there is need for more detail. My role in our team is often a bridging role – I span clinical and information science – and that seems to be a good fit for me using a language like Gherkin.

Next Steps

This work will feed into some user centred design and testing cycles for ePRO that I am very much looking forward to starting.