Say ‘cloud’ and by now anyone in the tech sector – and a good few people outside it – will be able to rattle off the benefits. Security, scalability, flexibility, resilience, cost-efficiency. Cloud is no longer a challenger delivery model – increasingly, it’s the dominant way of doing things.
For new companies, or companies building new applications, that’s good news. They can build from scratch in the public cloud and access the benefits straight away. Indeed, Gartner recently published a report revealing that the majority of cloud implementations are new builds.
The use of cloud for new builds is now well-established. Organisations always want new software, either brand new, large applications or smaller ones that sit at the edge of their system. Faced with the decision on where to run these apps, organisations are increasingly putting them directly into the cloud. If you were to start your own business now, you’d put it all in the cloud – it’s been done enough times now that the pathway to the cloud via public providers like AWS and Azure is well-trodden.
How do you move apps to the cloud?
But the flipside of that good news is that for those organisations that have essential, hefty applications sitting in a data centre, things are more complex.
It’s far from simple to recreate existing, organically-grown apps and guarantee that the new version will provide exactly the same results as the old one. Testing and the creation of test data is problematic, especially identifying the edge cases where differences in computation will produce different results.
Testing applications is particularly difficult where the passage of time is an important dimension. For example, interest calculations in banking and credit card applications or utility bill and statement systems can only be tested over several  periods. Because the bill is due on a certain date and automated

View Entire Article on