How we simplify a complex problem to an audience?

In this case I find it simpler to forget I am an engineer and think like I am one of them , a non technical person , I pretend to explain the issue to my parents. I compare in my head nuclear physics to what I do. I understand nothing about nuclear physics . 

By dissolving it to smaller parts, and to make analogies with subjests familiar to audience.

Carefully choose an example to project parts of the problem. Use the fishbone diagram for instance. And use a proper presentation method. (I'd recommend Prezi)

Focus on the determining factor(s) of the problem the most.

Communicate the current situation clearly without any fancy words/jargons/abbreviations.

Explain the approaches taken to rectify it, and how they resulted.

Ask for feedback to see if they got 'it'.