A key principle to understand about the foundations of Agile and DevOps is that they borrow from Deming, Lean and others belief that all decisions should be based on scientifically based evidence. This belief can be seen in Dr. Deming’s championing of statistical process control back all the way to the Physicist Daniel Bernoulli’s principle of hydrodynamics.
If we look closely at Bernoulli’s principle of hydrodynamics, we see that it is the basis of Agile and DevOps belief in iterative and incremental development. Bernoulli discovered that the pressure in a stream of fluid is reduced as the speed of flow is increased. So how does this relate to Iterative and incremental development in Agile and DevOps? Bernoulli found that as fluid flowed through a smaller pipe the fluid actually flowed faster due to less friction. This holds true when we release software in an iterative and incremental fashion, these small, frequent, and simple changes allow code to flow through the delivery pipeline much faster and with less friction resulting in the impact of the change being small, the risks reduced, and the opportunities for change increased.