The role of BDD in legacy IT systems

With legacy IT systems in banking back in the news today, it’s hard for us not to keep thinking about how behaviour driven development (BDD) could help avoid IT meltdowns like this.

“One problem that firms face, when dealing with legacy systems or integrating systems due to an acquisition, is the lack of documentation,” explains Alan Parkinson, Hindsight CEO and co-founder. “This poses a significant problem when the system needs updating. BDD is useful in documenting the current understanding of an existing system, and automation tools like Cucumber, Behat and SpecFlow can be used to check if this understanding is correct.

“This creates living documentation for the existing system, where all you have to do is run the automated checks with the BDD scenarios to discover if the requirements are being met. As and when you need to modify or replace the legacy system, you can use that living documentation to confirm that no regressions have taken place and that new functionality has been successfully implemented.”

Sounds like a certain UK high-street bank may have missed a trick there…

And this isn’t a use case for BDD that's only just occurred to us - far from it. Back in April 2014, Alan contributed to the Financial Markets Insights whitepaper “Are Financial Markets facing a Requirements Crisis? Does the answer lie in Behaviour Driven Development?” alongside other leading exponents of BDD including David Evans, Liz Keogh, Konstantin Kudryashov, Chris Matts and Dan North. It looked at how a number of firms in the financial sector are turning to BDD to ensure that complex requirements are identified, specified, communicated and continuously delivered. Alan’s contribution focused on the challenges around legacy IT systems and how BDD can play a role in overcoming these challenges. Download the whitepaper here.

Following on from the whitepaper, also in April 2014, Alan also co-led the discussion at a round table on “The Requirements Crisis in Financial Markets” hosted by the Realization Group, with delegates from across the financial industry including Bank of England, Barclays, JP Morgan and Aviva. Alan presented an appraisal of legacy systems in regulated industries, covering the need to re-capture requirements for these systems as they evolve to meet the new challenges of the digital age. Read more about the themes covered and the conclusions and ideas that emerged from the round table discussions here.

To discover more about BDD solutions offered by Hindsight, get in touch here.