Factory machines today usually have "lube systems", in which a central pump serves periodic charges of oil or grease from a reservoir through "lube lines" to the various "lube points" in the machine's bearing surfaces, bearing journals, pillow blocks, and so on. The timing and number of such "lube cycles" is controlled by the machine's computerized control, such as PLC or CNC, as well as by manual override functions when occasionally needed. This automated process is how all modern CNC machine tools and many other modern factory machines are lubricated. Similar lube systems are also used on nonautomated machines, in which case there is a hand pump that a machine operator is supposed to pump once daily (for machines in constant use) or once weekly. These are called "one-shot systems" from their chief selling point: one pull on one handle to lube the whole machine, instead of a dozen pumps of an alemite gun or oil can in a dozen different positions around the machine.