Under normal building practices 'shop drawings' refers to detailed plans used to fabricate things built in a shop. Occasionally I'll draw some up, most often freehand, and not often to scale. I do them so I can send them off to an engineer (to make real ones). On rare occasions we will actually refer to shop drawings in our shop, but not often.
Shop drawings in our shop take on a whole different meaning. For us they are quick scribbles done in the shop (or on a worksite). Most often they are drawn with a piece of soap stone on the welding table, or if that is full, on the shop floor. On a worksite they are done with a felt pen or carpenter's pencil on a scrap of wood. They can be drawn in the dirt with a sharp stick as well.
Today Chris was in our shop and we were discussing how to build a rather complex piece. Simply describing how we were going to build it wouldn't do. He whipped a piece of soapstone out of his pocket and then crouched down to draw on the floor. In a couple of minutes he had drawn multiple versions and angles of viewing on the floor, complete with square tubing sizes and quantities. The notes on the floor described how pieces would be angled, where they would be welded and how other pieces would fasten on. All the information we needed was there.
Once we had settled on the solution to this complex problem there was no need for anything more. Cleanup was simple. Being in a heavy traffic area it would be gone in a few minutes. It was a green solution for no paper was used in it's execution. And as long as it works it was plenty good enough for us.