Yields for Sand Casting
This section describes how yields are calculated for all Casting processes, except for coremaking processes.
Final Yield = Final Output Volume / Input Volume
Final yield affects labor and overhead costs per part (it does not affect material cost—but see Non-foundry Yield in
Material Cost and Utilization for Sand Casting). It is the fraction of the total number of parts created by this process in the current production scenario that will survive as good parts once any secondary processes are completed. That is, final yield is the fraction of parts created by this process that are
not discarded as scrap parts, either by this process or by a downstream process. Final yield depends on the following:
• Final output volume (product of the annual volume and number of production years, specified in the Production Scenario screen of the Cost Guide)
• Input volume (see the formula below). This is the total number of parts produced by this process, including all parts discarded as scrap from this process or downstream processes.
Input Volume = Local Output Volume + Number of Scrap Parts for This Process
Input volume is the total number of parts produced by this process in the current scenario, including all parts discarded as scrap from this process or downstream processes. It is the sum of the following:
• Local output volume (see the formula below). This is the number of parts produced by this process, excluding parts discarded as scrap by this process, but including parts that are discarded as scrap by downstream processes.
• Number of scrap parts for this process (see the formula below)
Local Output Volume = Final Output Volume + Number of Scrap Parts Downstream
Local output volume is the number of parts produced by this process in the current scenario, excluding parts discarded as scrap by this process, but including parts that are discarded as scrap by downstream processes. It is the sum of the following:
• Final output volume (product of volume and number of production years, specified in the Production Scenario screen of the Cost Guide)
• Number of Scrap Parts Downstream. This is the number of parts discarded as scrap by downstream processes.
Number of Scrap Parts for This Process =
(Local Output Volume / Good Part Yield) – Local Output Volume
Number of scrap parts for this process is the number of parts produced by this process in the current scenario that are discarded as scrap by this process, before any downstream process is performed on them. It is a function of the following:
• Local output volume (see the formula above)
• Good part yield (specified by the machine property Good Part Yield). This is the fraction of parts produced by this process that are not discarded as scrap by this process but may be discarded as scrap by downstream processes.