[krasicki]

Design a notation based on existing norms to whatever specificity you deem adequate).

I like process boxes with four sides.

Left side takes input, the right spits output.

Top side takes constraints, rules, or links to specs.

Bottom accepts triggering mechanism, temporal/sequential constraints, polling, and other controls.

Complex Processes get decomposed down to autonomous objects that can be programmed as desired.

Many of the stripped down existing iconic notations can be similarly instrumented to be useful. Be your own guru.