Machining Time / Machine Time

Machining time is the time when a machine is actually processing something. Generally, machining time is the term used when there is a removal of unwanted material. For example, in a drill press, machining time is when the cutting edge is moving forward and making a hole. This is known as subtractive manufacturing, as opposed to the relatively new method of additive manufacturing, such as seen in 3D printing.

For the purposes of continuous improvement planning, “machine time” is also used to describe other automated processes, such as when a machine installs screws in a case automatically. While this is not technically “machining time”, the math and planning behind the process works the same way.

The machining time, combined with the loading and unloading time, yields the machine cycle time, or the amount of time that the machine must commit to each part, once it is set up to run that product.

Lean puts a strain on the total machining time that is available. Because we don’t like to run large batches, we must do frequent changeovers. Each changeover takes away some of the machine time available during the day. On the surface, this seems counter to production goals. But small batches have been proven time and time again to make work flow better.

Of course, to make sure enough machining time is available, you have two options. The first is to reduce the machine cycle time, whether the actual machining time, or the loading and unloading steps. This can be done with product redesign, or through kaizen.

The other option, and generally the one with more potential, is setup reduction. It reduces the time that the machine is not processing a part, so more time is available to produce.