The Mining Company The Mining Company owns and operates several open-pit mines throughout the Western United States. The Salsa mine has begun to show a profit. Open-pit mining is only profitable after removal of overburden (called stripping) by tractors, belly dumps, scrapers and similar equipment. Unlike overburden copper ore is hard and rock-like. It is freed by blasting, scooped up by giant electric shovels and carried to the top of the pit in electra-haul dump trucks. Ore is then crushed and copper particles extracted. A rift between pit operators and the mechanical maintenance department is brewing. Pit operators complain that the mechanical maintenance department is overly protective of the heavy earth moving equipment. Pit operators, who are primarily interested in getting a maximum amount of ore to the processor push equipment to the limit. According to the mechanics, "No sooner do we get a piece of equipment into operation, than it's back here in the shop because of some careless jerk."   Figure 1 The Mining Company ___________________________________________ John Williams walked down to the shop floor at 08:00am. All repair bays were filled with machines to be repaired. He said to himself... "We're really going to get a lot done today. Those two scrapers will be nearly finished by the end of this shift and those two tractors will be ready return to the pit by noon." Just as John finished reading the job tickets, Matt Reynolds, a front-line Manager from the pit, walked into the shop. Williams: What do you say, Matt? Reynolds: How fast can you get me two belly dumps? Williams: I don't know off-hand. Reynolds: Well, I have one that needs to come in for repairs pretty soon and I'm already running short. Williams: Yeah? Reynolds: No fooling, it's urgent ... or it will be in a couple of hours! I need em bad. You've got to have them ready just as fast as you can. Williams: OK. I'll get right on it. Reynolds: Thanks. John Williams went to where the scrapers were being repaired and told his men to stop work on them and to work on the belly dumps. By 10am it looked like things were coming along fine. As John Williams went into his office looking for some papers, Rex Allen rushed into the shop. Rex Allen: Where are my scrapers? I don't see your men working on a single one. We just lost another one and I'm really running short. I'll never get any dirt moved if you don't get me a scraper. It's more important to get me that scraper than anything else your men can do. If we don't move that overburden off the South rim there won't be any ore running in about 8 hours. Williams: OK, OK, I'll get right on it. John Williams went over to the bay where his men were working on a belly dump. "I want you men to stop working on that belly dump and get on one of those scrapers. Find one you can have finished by 4pm. The mechanics were obviously bothered. Mechanic 1: What's going on here? This morning you were all excited about getting belly dumps ready. Now it's a scraper. You think all we have to do is run equipment in and out of the shop. Mechanic 2: Yeah, just when we get going on one job they have us jump to another. We lose 30 minutes every time we run one of these monsters out and another one in. Williams: Just do as you're told. Rex will raise hell over this if we don't get a scraper fixed. Lunch finished and all mechanics were busy working on equipment. The phone rang and John Williams answered. Williams: Hello. Sweeney: Sweeney here. Williams: What's up? Sweeney: Jack Davis just called and gave me pressure to get out an 80-ton Electra-haul. How soon can we have one ready? Williams: We're not working on any right now. Sweeney: Well, you better get on it -- and quick. Ore can't get to the mill without trucks to haul it. Williams: OK John knew what his men were going to say when he told them to stop what they were doing and to start working on the Electra-haul.