1         What is a System?

Everyone uses the term and has an intuitive notion of what a system is, but there is a formal definition. INCOSE and ISO/IEC/IEEE define a system as:

“A combination of interacting elements organized to achieve one or more stated purposes.”

This general definition covers almost everything you can think of including household appliances, transportation management systems, the latest weapon system, even the solar system, all of these are systems.

The two elements of this definition drive many of the processes we use. They are:

• Elements that interact. A system is a sum of parts that must work together.
• Stated purpose. Those elements interact to serve a clearly defined purpose.

Without understanding the purpose, defining what a project must build becomes impossible. But with the purpose defined, those parts and how they are integrated can be measured at every step of procurement from preliminary design to operation.

Reference:  ISO/IEC/IEEE 15288-2015, ISO/IEC/IEEE International Standard – Systems and software engineering – System life cycle processes, https://standards.ieee.org/ieee/15288/5673/