Drive testing upstream and save costs

Regarding the costs, I am inclined to say that, on average, the Dynamics 365 Business Central project goes 25% over budget in the end, mainly due to after go-live bug fixing. I am not going to elaborate much on who's to pay for this, but my experiences are that it's often the implementation partner. The math is quite simple if assuming that to be the case. If you're spending 25% extra on your own account at the end of the line, why not push it upstream and spend it during the development phase on automated testing, building up a reusable collateral?

During my time at Microsoft in the 2000s, research had been performed on the cost of catching a bug in the different stages of developing a major release of a product. If my memory is not failing, the cost of catching a bug after release was found to be approximately 1,000 times higher than when catching the bug already at requirement specification.

Translating this to the world of an independent software vendor (ISV), this might roughly be a factor 10 lower. So, the cost of catching a bug all the way downstream would be 100 times higher than all the way upstream. In case of a value-added reseller (VAR) doing one-off projects, this could be another factor of 10 lower. Whatever the factors would be, any spending upstream is more cost effective than downstream, be it more formalized testing, better app coding, code inspection, or more detailed requirements specifying.