Today control system is a science with art still playing an important role.
what do you mean by saying a science with art?
This demonstrates the importance of the wise use of commas: there should be one between 'science' and 'with'--
'Today's control system is a science, with art still playing an important role.'
But the context has nothing to do with art.
The phrase with art must be a part that modify science, rather than to be connected with the latter part .
Do you think so ?
I agree with Mr Micawber. By art, they could mean that science alone is not enough- art could cover many things here.
If we say something is an art not a science, we mean that it involves judgement rather than simply assessing things statistically, say, so politics is an art not a science. Presumably that is what is behind this sentence.