As you look at any of the machine tools on display at IMTS, you may ask yourself, Does my shop have the work it will take to keep this machine cutting?
Don't answer yet. Instead, pause to consider whether that's the right question. For many shops, a better question may be this one: Are there operators or machinists in my shop right now who could work more efficiently if they had this machine available?
I can understand the habit of asking question number one. At one time, whenever I visited a shop, I would make a point of counting how many machine tools were actually making chips. Counting these machines seemed like a good way to measure efficiency. Assuming the shop had enough work to go around, the proportion of machines that were in-cut would indicate how effective that shop was at keeping the work flowing. Or so I thought.
For many shops, this measure of efficiency is exactly right. However, there are many other shops—perhaps a growing number—in which the picture of effective asset utilization has changed. The reason has to do with economics. While the cost of many types of CNC machines has come down, other costs have not.
How much the cost of some machines has dropped was apparent to me the day I visited a shop that had a vertical machining center 15 or more years old running across the aisle from a VMC only 1 year old. The two machines were comparable in terms of size and power, but according to the shop owner, the newer machine's purchase price was less than half of what the older machine's price had been. And that's before allowing for inflation.
Meanwhile, that same shop owner had seen other costs dramatically rise. Labor costs in particular have gone up—at this shop and throughout the industry. With fewer people choosing vocations in metalworking, the ones who remain command greater compensation.
All of this helps to explain why a machine may be a good buy today even if it will see a level of idle time that would have been too costly in years past. With the cost of machine hours going down and the cost of labor hours going up . . . a little machine idle time may be a bargain if the corresponding in-cut time lets skilled personnel work more productively.
Effective asset utilization is still the goal. However, when you think in these terms, think first about which of your shop's assets are truly the most expensive.