Shakeout provides the following option:

For machines whose Shakeout Type is table, the default number of parts processed in one machine cycle is the maximum number of parts that can fit on the machine (see Shakeout Machine Selection). You can override the default, and specify a smaller number with this setup option. Note that the maximum number of parts you can enter is bounded above by the maximum number of parts that can fit on the currently selected machine. See also Shakeout Formulas.