Bend Brake

aPriori uses the formulas below to determine costs associated with this process.

Accounting Calculations

Labor Time = Cycle Time * Machine Labor Time Standard *
Machine Labor Ratio

Labor time is the product of the following

  • Cycle time (see Cycle Time Calculation)

  • 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.

  • Machine labor ratio (specified as a machine property)

Labor Cost = ((Labor Time / 3600) *
Labor Rate) / Process Yield

Labor cost is a function of the following:

  • Labor time (see formula above)

  • Labor rate: this is the product of the following:

    • Machine property Labor Rate
    • Cost model variable laborRateAdjustmentFactor (1 in starting point Digital Factories)
    • Machine property Work Center Labor Rate Factor (1 in starting point Digital Factories)

  • Process yield (see formula below)

Amortized Batch Setup = (Machine Setup Time *
(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)

Period Overhead = Labor Cost * Machine Period Overhead Coefficient

Period overhead is the product of the following:

  • Labor cost (see formula above)

  • Machine period overhead coefficient (specified as a machine property)

Process Yield = 1 / (Machine Process Yield/100)

Process yield depends on the machine property Process Yield.

Cycle Time Calculation

Cycle Time = Load and Unload Time +
Number of Bends * (Bending Time + Part Manipulation Time)

Cycle time depends on the following:

  • Load and unload time (obtained from lookup table; see below; increases with part mass, which increases with material density).

  • Number of bends (obtained from GCD extraction)

  • Bending time (specified as a machine property)

  • Part manipulation time (obtained from lookup table; see below; increases with part mass, which increases with material density)

Load and unload times and manipulation times by part mass are contained in the lookup table bendBrakeHandling.

Bending Operation Cycle Time Calculation

Cycle Time = Number of Bend Operations * (Bend Cycle Time + Manipulation Time Per Bend)

  • Number of Bend Operations: This can take the following values:

    • 2: If it is a standard Hem GCD and Number of Outer Bends And Forms is 0.

      • Number of Outer Bends And Forms: This is the total count of ‘Lies Outside’ GCD Relations comprising Form, Shear Form, Straight Bend, and Multi Bend GCDs.

      Or if the Define When Gussets Can be Formed setup option is set to ‘After Bend - All at once’ and Gusset Count is greater than 0.

      • Gusset Count: This is the total count of Form GCDs that have a Sub Type property of GUSSET.

    • 1 + Gusset Count: If Define When Gussets Can be Formed is set to ‘After Bend - 1 by 1’.

    • 1: In all other circumstances.

  • Bend Cycle Time: This is specified by the machine property Bend Cycle Time.

  • Manipulation Time Per Bend: aPriori performs a lookup in the smBendBrakeHandling table and returns the Manipulation Allowance value corresponding to the Weight entry that is greater than or equal to the Finish Mass of the part.