The concept lies with the inventor. This is what needs to be made clear to the expert technicians so that they could understand the basics and implement some innovative approaches in order to yield the best results. After listening to what the inventors think, the engineers create a concept design and show the same too them. Most of the times, the designs do not get approved because some or the other thing is always lacking in it. But frequent sessions and meetings with the inventors make the concept really clear to the engineers and as they start reading the expressions and mind of the inventors, they successfully lead to exact results and ultimately the concept design gets approved.