Laser Cut, Oxy Fuel Cut, Plasma Cut
aPriori uses the formulas below to determine costs associated with these cutting processes (used for plate rolling).
Accounting Calculations
Labor Time = Cycle Time * Machine Labor Time Standard
Labor time is the product of the following
• Machine labor time standard (specified as a machine property). This value reflects the amount of time spent by machine operators in between machine cycles, including time performing maintenance and cleaning tasks as well as time pausing between tasks. The amount is expressed as a cycle time multiplier.
Labor Cost = (Labor Time / 3600) * Machine Labor Rate
Labor cost is a function of the following:
• Labor time (see formula above)
• Machine labor rate (specified as a machine property)
Direct Overhead Cost = (Cycle Time / 3600) * Machine Overhead Rate
Direct overhead cost depends on the following:
• Cycle time (see formula below)
• Machine overhead rate (specified as a machine property)
Amortized Batch Setup =
(Machine Setup Time * (Machine Labor Rate + Direct Overhead Rate)) / Batch Size
Amortized batch setup is a function of the following:
• Machine setup time (specified as a machine property)
• Machine labor rate (specified as a machine property)
• Direct overhead rate (see
Direct and Indirect Overhead)
Cycle Time Calculation
Cycle Time = (Burn Time + Pierce Time + Rapid Traverse Time + Scrap Cutting Time + Shuttle Time) /
Machine Number of Heads
Cycle depends on the following:
• Burn time, which depends on the following:
o Cross-section thickness
o Material type—aluminum, for example, cuts faster than steel
o Machine wattage
o Blank size
o Feature perimeters—burn time increases with hole size.
o Feature radii of curvature—tighter cuts are slower.
• Pierce time, which depends on the following:
o Number of holes
o Cross-section thickness
o Material type
o Machine wattage
• Rapid traverse time, which depends on the following:
o Blank size
o Machine’s rapid traverse feed rate
• Scrap cutting time
• Shuttle time (increases with blank size)
• Machine number of heads (specified as a machine property)
Pierce and burn cutting rates by machine watts and material type and thickness are contained in the following lookup tables:
• Laser smNestingCutRate
• Plasma smNestingCutRate
• OxyFuel smNestingCutRate