Everyone knows that there's a correct way to carve poultry into parts. In fact, basic carving methods haven't changed much since the time of the Roman Empire a couple of thousand years ago. If you want to be considered a great cook, you need to learn these ancient lessons. For chickens, it usually sounds something like this:
Place the chicken on the cutting board. Pull the leg away from the body and cut through the joint between the leg and the body to separate the leg. Place the chicken leg on the cutting board. Cut through the joint to separate the drumstick from the thigh. ...
Enterprise Architecture Lesson No. 1: When defining the start and end points of enterprise business processes and the scope of their supporting enterprise applications, cut through the joints.
This is the Natural Boundaries Principle and the concept of loose coupling applied to the enterprise level. The Natural Boundaries Principle is one of the most important enterprise architecture principles. It goes something like this: "Design systems around natural boundaries of business processes and data, tight-coupling within and loose coupling between." Business process and system scope, especially enterprise business process and enterprise system scope should not be arbitrary. Look for the joints, places where your enterprise chicken bends!
If you ignore natural breakpoints when carving either poultry or enterprise business processes and supporting systems into parts, it is really messy. One of the most obvious symptoms of improper enterprise carving methods is a messy multitude of interfaces. Another symptom is enterprise projects that are significantly delayed because they have to figure out how to deal with that messy multitude of interfaces.
If you get the natural boundaries right, it simplifies the number and complexity of interfaces. It also enables loose coupling between enterprise applications. This lowers costs by reducing complexity and redundant data and increases flexibility by maximizing autonomy between systems. Lower costs, increased flexibility. That's why the Natural Boundaries Principle is so important to your enterprise.
So how do we find the natural breakpoints in our enterprise business processes and systems? Well, you can't see the parts without looking at the whole. It's a basic engineering design principle. We have to "take a gander" at our enterprise goose, the whole thing. That's why enterprise architecture includes the development of enterprise business process and data models.
Avoid spending a lifetime creating the models of your enterprise with 20 people locked up in conference rooms filled with flip-chart wallpaper. Take advantage of what's already available from industry associations. Do some internal and external research to find models you can refine and utilize. Take a look at how market-leading software companies modularize their suite of solutions in each functional area, because that's where you're most likely to get your chicken parts from.