A system is a set or arrangement of things so related as to form an organic whole.

When an ADDer activates a system, s/he is freed from having to remember the individual steps and less likely to get distracted in the middle of a task.

Most people are a little fuzzy on this one, probably because the last systems development training we received was potty-training. How many of us forget to do what-comes-next when we going to the bathroom? Or even give it a thought?