Time and profits are wasted as your employees look for tools and material on the jobsite.
On the way to my favorite fishing hole with two of my close friends, we stopped at one of our jobsites. I did my normal jobsite safety inspection, which took almost an hour while they looked around at what the crews were doing. Neither had ever been involved in construction and both were very interested in what they saw.
When we got back into my truck, the older gentlemen asked me why we didn't use a quartermaster to provide everything that the craftsman needs to get his job done. The job was behind schedule and we had talked about our skilled craft shortage before we got to the jobsite.