I’ve done this with a lot of difference companies and a lot of different development and project management philosophies though, and they all fail.
We’ve gone full waterfall, we’ve gone full agile and everything in between. We’ve done long detailed requirement specifications and we’ve invited companies into the heart of our business, to let them literally work inside our offices sitting shoulder to shoulder with our domain knowledge. None of it produces high quality software.
The highest quality software we have, aside from a few small suppliers, is the software we build ourselves. It’s anecdotal again, but it’s the same story I hear in my network of digitalisation managers across the countries public sector and banking.