Many CNC mills automatically calculate machining time, which is an important statistic for calculating productivity.
Machining time is a term used to describe the amount of time a machine actually spends cutting, milling, or modifying a part to be machined. It is part of what is known as the cycle time of the machine, that is, the total amount of time it takes to load and unload a piece of material, as well as the amount of time it takes to cut that material. Machining time can be calculated automatically on many CNC or computer numerically controlled machines to help improve manufacturing efficiency and cost per cut.
Processing time is another term synonymous with machining time. This calculation only measures instances where a drill or cutting tool on a machine is making cuts or removing material from a part. If, for example, a plate is to be cut on a table saw, the machining time would be the collective instances where the blade is actually removing material; this means that the blade is actively moving and cutting the material for processing. Many machines, such as CNC lathes, will have extra run time, which is any instance where the machine is active and material is on the work surface, but no cutting is being done or material is not being removed. An example of such a case would be when the drill is moved to a new position in the material in preparation for another cut.
A company might try to calculate the machining time of various machines in a shop to find where productivity has decreased and how it can be improved. A machine, for example, with a slow machining time can be upgraded or replaced with a more efficient tool that can complete the same job in less time. Some types of machines can combine functions to eliminate loading and unloading, thus improving the efficiency of a machining process. Companies can also use this calculation to determine the total cost of the finished product; it can be part of a formula that includes raw material cost, machining time, packaging costs, shipping costs, etc.
Another important reason to determine the time spent on machining is to avoid damage to the machines themselves and to know when maintenance might be required. A manufacturer may recommend a maintenance schedule based on how long the machine is in operation, and bits may also need to be replaced after a certain amount of use.