How we change what others think, feel, believe and do
Understand something by considering it as a whole system. Analyze not just the parts but also the relationships between the parts.
You can use decompositional reasoning to identify parts, but go beyond this in considering the additional things beyond just the parts.
I argue for a new square in the middle of town by considering the aesthetics of space and the relationships between the empty square and the tall buildings around it. I also consider the dynamics of movement and pauses of people during parts of the day and weekend, including in other squares.
A 'system' is a set of connected parts, each of which may be considered as system in its own right. An individual part can have any number of different relationships with any other part of the system. Thus there are relationships between me and the seat I am sitting on based on space, friction, electromagnetism, gravity, and so on.
A closed system assumes that there is no external influences. Science likes closed systems as this allows deterministic answers.
An open system assumes that everything can be connected to everything else. The ultimate open system is the universe, with any part being able to influence any other part. This is much harder to analyze and understand, but it is also much more real.
Systems also may consider whether or not each part of the system has purpose and will. Thus, for example, a company is made up of people, all of whom may have purpose beyond that of the company (and thus making achieving the company's purpose more complex than it might at first seem).
And the big