Labor and Setup Costs for Sand Casting
All casting processes except Melting use the formulas in this section to determine labor and setup costs. The Melting and Stock Core processes do not incur labor or setup costs.
Labor Cost = Labor Time * Labor Rate / Final Yield
Labor cost depends on the following:
• Labor time (see formula below)
• Labor rate (specified as a machine property)
Labor Time = (Cycle Time * Number of Operators * Labor Time Standard) +
Labor Handling Time
Labor time depends on the following:
• Cycle time (see the process-specific Cycle Time formulas). Note that cycle time is 0 for Stock Core.
• Number of operators (specified as a machine property)
• Labor time standard: specified as the machine property Labor Time Standard. This multiplier is used to account for otherwise unaccounted for factors that affect labor time, such as operator fatigue or time spent by the operator for cleaning or maintenance.
• Labor handling time (see below)
Labor Handling Time = Elapsed Handling Time * Number of Handling Operators
This is 0 for automatic moldmaking. For other processes, values for elapsed handling time and number of handling operators are interpolated from values looked up by mass in the lookup table tblHandlingTimes. The mass that requires handling varies by process.
For all manual moldmaking processes, the mass that must be handled is Mass Sand per Mold. See
Mold Making:
For all refractory coating processes, the following list provides information about the mass that must be handled:
• Manual moldmaking processes: see Mass Sand per Mold in
Mold Making. (Since the mass that must be handled is the mass of the sand for the entire mold, labor handling time is amortized over the number of cavities in the mold.)
• Coremaking processes: see Mass Sand per Core in
Coremaking—All Except Stock Core and see
Coremaking--Stock Core. (Labor handling time is the sum of the handling times for the cores.)
• Mold Refractory Coating: see Mass Sand per Mold in
Mold Making. (Since the mass that must be handled is the mass of the sand for the entire mold, labor handling time is amortized over the number of cavities in the mold.)
• Core refractory coating: see Mass Sand per Core in
Coremaking—All Except Stock Core and see
Coremaking--Stock Core. (Labor handling time is the sum of the handling times for the cores.)
• Refractory Coating Air or Oven Dry: see Mass Sand per Mold in
Mold Making, see Mass Sand per Core in
Coremaking—All Except Stock Core, and see
Coremaking--Stock Core. (Labor handling time has two components: mold handling time and core handling time. Mold handling time is amortized over the number of cavities in the mold. Core handling time is the sum of the handling times for the air-dried or oven-dried cores.)
• Shakeout: mass that must be handled is the sum of the following:
o Mass Sand per Mold: see
Mold Making.
o Mass of the sand in all cores: see Mass Sand per Core in
Coremaking—All Except Stock Core. See also
Coremaking--Stock Core.
• Visual Inspection: see Mass Before Machining in
Material Cost and Utilization for Sand Casting.
Note that for manual moldmaking, the mass that must be handled includes the sand for the entire mold, so labor handling time is amortized over the number of cavities.
For coremaking processes and Core Refractory Coat, the As with other processes, coremaking and core coating elapsed handling time and number of handling operators are interpolated using tblHandlingTimes.
For all processes, the interpolated value is based on the table rows whose Max Weight values straddle the mass that must be handled. If the mass falls below the minimum mass listed in the table, the handling time is considered negligible, and is set to 0. If the mass exceeds the maximum mass listed in the table, aPriori uses the values in the row with the maximum mass.
Amortized Batch Setup =
(Setup Time * (Labor Rate + Direct Overhead Rate)) / Batch Size
Batch setup cost per part depends on the following:
• Setup time (specified as the machine property Setup Time)
• Labor rate (specified by the machine property Labor Rate)
• Direct overhead rate (see
Direct and Indirect Overhead)
• Batch size (specified in the Production Scenario screen of the Cost Guide)