Engineering has not really changed in end results for centuries: however, the tools and methods have. For example, the Rolls-Royce Merlin engine of WW2 went through many changes, including fuel refinements, adding a supercharger, and fuel intake methods. Designed by engineers, it was then built out of wood to look for problem areas, then steel and aluminum, first with just a couple of cylinders for proof of concept, then expanded to a full engine that went through exhaustive testing before being mounted on an actual aircraft, and finally the flight test. In addition to this, the whole engine manufacturing process includes testing. Testing was performed in the early stages, and they would pick one out of five engines and run it until it failed, this number would go to 1 in 100 over time, as fewer defects were detected. Today, there are many other ways to ensure quality and speed design, but the end result is still the same. The other interesting thing was how they also had to rethink how to make the engines, to begin with, as usual, it would take a team of engineers to produce such an engine, but they needed as many as could be produced, and their labor force were not engineers.
Today we do what is known as Model-Based Systems Engineering (MBSE) a software-based tool to look for flaws and weed them out before production. Still, in systems engineering as we look at not only the engine but how it would be used. Like before, models are made, this time in software. The main advantage here is that things do not have to be made to examine their properties but can be simulated instead. MBSE has taken on some importance not just for cost, but for the schedule and cost of the final project. Another example of doing the engineering upfront rather than building and experimentation. This is done virtually.
With newer tools, MBSE does not even need programming skills but can be accomplished in something much closer to human language, while still synaptic, still maps to parts of speech such as nouns, verbs, adjectives (itlities), and adverbs to describe the system and interfaces.
As with all systems engineering, whether you’re adding to a system or making a new one, still comes down to the four basics: requirements, behavior (or Concept of Operations), architecture, and verification on validation. By being able to do this is in a software model, much of the work can be performed without actually building anything which is a huge leap in the design process. But as always, the requirements and how you are going to use them are paramount. In the case of the Merlin Engine, was the mainstay of the British air force powering everything thing from the Spitfire to the Mosquito and later the US P-51 Mustang.