A system and method of describing and executing autonomous or autonomous device behaviors via a computer-implemented system incorporating a fuzzy language, a simulator, and one or more runtimes. The fuzzy language combines high level behaviors and produces a set of parameter descriptions. The parameter descriptions are behavior characteristics whose values are not yet necessarily known or selected. The parameter descriptions are used via simulation to find relevant parameters and acceptable parameter values that result or will result in the autonomous or semi-autonomous device behaving as desired.