Sustainability Data for Machining

Note: See Sustainability Cost Model Overview for general information about the carbon information data that aPriori provides for all supported processes.

The Machining cost model provides Sustainability data for the following processes:

Note: For a full list of the individual operations that support Sustainability within each of the processes, see the aPriori Professional Release Notes.

2/3 Axis Lathe and 3 Axis Bar Feed Lathe with Sub Spindle

The 2 Axis Lathe, 3 Axis Lathe, and 3 Axis Bar Feed Lathe with Sub Spindle (3ABFL) cost model provides the following Sustainability outputs on the Part Details / Sustainability tab in aPriori:

  • Supports Sustainability: Yes, or Partial. The value will be ‘Yes’ if aPriori is able to calculate operation Energy Usage for 100% of cycle time, otherwise it will be ‘Partial’. aPriori shows the percentage in the Cycle Time With Operation Energy Calculated value, visible in Formula Dependencies. For more details, see the description of Calculated Energy Consumption.

  • Primary Material Carbon Factor: not applicable. aPriori leaves the cell blank.

  • Energy Carbon Factor, Logistics Carbon, Annual Carbon, and Total Carbon: the calculations for these variables are the same for all processes – see Sustainability Cost Model Overview.

  • Material Carbon: aPriori sets the Material Carbon value to zero. Although you can see the Material Carbon formula in the Formula Dependencies window, all the cells are blank other than the Final Yield percentage.

  • Process Carbon: see 2/3 Axis Lathe and 3 Axis Bar Feed Lathe with Sub Spindle. Note that the Indirect Machine Power calculation included in the Process Carbon calculation is the same for all processes – see Indirect Machine Power Calculation. Also see Process Carbon in the Sustainability Cost Model Overview for some general points about the Electricity Process Carbon and Other Process Carbon calculations.

Process Carbon Calculation for 2/3 Axis Lathe and 3ABFL

Process Carbon = Electricity Process Carbon + Other Process Carbon

  • Electricity Process Carbon: the primary source of process carbon based on energy factors and energy consumption. Calculated as (Energy Carbon Factor * Energy Consumption ) / Final Yield:

    • Energy Carbon Factor: the CO2 equivalent factor for a unit of energy consumed. Specified by the top-level Digital Factory variable Electricity Carbon Factor (data provided by Ecoinvent). You can update the value in the Formula Dependencies or in the Digital Factory if you have a factor that you think is more representative of your selected location.

    • Energy Consumption: the energy consumption of the machine for the process, including direct and indirect energy consumption. See formula below.

    • Final Yield: the number of acceptable parts at the end of the entire part routing divided by the number of this process’ starting pieces including scrap. See Yields For Machining.

  • Other Process Carbon: (if applicable) any source of process carbon, including additional sources of carbon not related to electricity. If not applicable, this will have a value of 0.00.

Energy Consumption = (Direct Machine Energy Consumption + Indirect Machine Energy Consumption)

  • Direct Machine Energy Consumption: the direct energy consumption of the machine. By default, aPriori calculates this using the Calculated Energy Consumption calculation.

  • Indirect Machine Energy Consumption: the indirect energy consumption of the work center based on the overhead facility power usage. Calculated as (Indirect Machine Power * Cycle Time):

    • Indirect Machine Power: the indirect power of the work center based on the overhead facility power usage. The calculations are the same for all processes – see Sustainability Cost Model Overview. If you override the value, the Process Carbon value is adjusted accordingly.

    • Cycle Time: the time for one complete cycle of the applicable machine to make a single part. Includes the process times for each stage of the process. For details, see Process Cycle Time. If you override the Cycle Time Adjustment Factor or Process Time elements, the Process Carbon value is adjusted accordingly. If you override the total Cycle Time value, aPriori uses the Cycle Time Energy Consumption calculation instead of the Calculated Energy Consumption calculation.

Calculated Energy Consumption

Calculated Energy Consumption = Calculated Energy Consumption * Cycle Time Adjustment Factor

  • Calculated Energy Consumption: aPriori sums the Energy Usage value of each operation to produce a Calculated Energy Consumption figure. See Example Calculated Energy Consumption Calculation. Cycle Time With Operation Energy Calculated (visible in Formula Dependencies) indicates the portion of cycle time that has operation energy calculated, represented as a percentage of cycle time in brackets. For example, a value of ‘2m6s (90%)’ indicates that 90% of cycle time has operation energy usage calculated, which amounts to 2 minutes and 6 secs. A value of 100% indicates that aPriori has calculated operation energy usage for 100% of cycle time. If you override the Calculated Energy Consumption value or the Cycle Time Adjustment Factor, the Process Carbon value is adjusted accordingly.

  • Cycle Time Adjustment Factor: the value of the cost model variable cycleTimeAdjustmentFactor. This is set to 1 in starting point Digital Factories.

Cycle Time Energy Consumption

This is the energy consumption based on the cycle time and power factors. Calculated as: (Machine Power * Applied Power Factor) * Cycle Time:

  • Machine Power: specified by the machine property Machine Power.

  • Applied Power Factor: aPriori applies a power factor of 1 to the Machine Power .

  • Cycle Time: the time for one complete cycle of the applicable machine to make a single part. Includes the process times for each stage of the process. For details, see Process Cycle Time.

3/4/5 Axis Mill

The 3 Axis Mill, 4 Axis Mill, and 5 Axis Mill cost model provides the following Sustainability outputs on the Part Details / Sustainability tab in aPriori:

  • Supports Sustainability: Yes, or Partial. The value will be ‘Yes’ if aPriori is able to calculate operation Energy Usage for 100% of cycle time, otherwise it will be ‘Partial’. aPriori shows the percentage in the Cycle Time With Operation Energy Calculated value, visible in Formula Dependencies. For more details, see the description of Calculated Energy Consumption.

  • Primary Material Carbon Factor: not applicable. aPriori leaves the cell blank.

  • Energy Carbon Factor, Logistics Carbon, Annual Carbon, and Total Carbon: the calculations for these variables are the same for all processes – see Sustainability Cost Model Overview.

  • Material Carbon: aPriori sets the Material Carbon value to zero. Although you can see the Material Carbon formula in the Formula Dependencies window, all the cells are blank other than the Final Yield percentage.

  • Process Carbon: same as for Process Carbon Calculation for 2/3 Axis Lathe and 3ABFL.

Drill Press

The Drill Press cost model provides the following Sustainability outputs on the Part Details / Sustainability tab in aPriori:

  • Supports Sustainability: Yes, or Partial. The value will be ‘Yes’ if aPriori is able to calculate operation Energy Usage for 100% of cycle time, otherwise it will be ‘Partial’. aPriori shows the percentage in the Cycle Time With Operation Energy Calculated value, visible in Formula Dependencies. For more details, see the description of Calculated Energy Consumption.

  • Primary Material Carbon Factor: not applicable. aPriori leaves the cell blank.

  • Energy Carbon Factor, Logistics Carbon, Annual Carbon, and Total Carbon: the calculations for these variables are the same for all processes – see Sustainability Cost Model Overview.

  • Material Carbon: aPriori sets the Material Carbon value to zero. Although you can see the Material Carbon formula in the Formula Dependencies window, all the cells are blank other than the Final Yield percentage.

  • Process Carbon: same as for Process Carbon Calculation for 2/3 Axis Lathe and 3ABFL.

Example Calculated Energy Consumption Calculation

aPriori sums the Energy Usage value of each operation and produces a final Calculated Energy Consumption figure. Here is a simplified example using the 3 Axis Mill process:

  1. aPriori calculates an Energy Usage value for each individual operation, for example:

    1. Side Milling produces two Energy Usage values for Curved Wall:1 and 2.

    2. Facing produces four Energy Usage values for Planar Face:1, 2, 3 and 4.

    3. Slot Milling produces two Energy Usage values for Slot:1, and 2.

  2. aPriori sums the individual Energy Usage values and displays the result as the Calculated Energy Consumption value.

Note: The cost model is sensitive to changes in the values of some lathe and mill GCD setup options. For example, changes to Requested Feed Per Rev or Requested Tool Cutting Speed may impact energy consumption. For some operations (for example Rough Milling on Pocket GCDs), aPriori provides the information-only setup options Power Requirement for Requested Cutting Parameters and Spindle Speed Requirement for Requested Cutting Parameters indicate how much of available machine power is required for the operation.