Age Process

The Age process is described on the following sections:

Machine Selection for the Age Process

For the Age process, aPriori selects the feasible machine with the lowest overhead per part. Overhead per part is the sum of the machine properties Direct Overhead Rate and Indirect Overhead Rate, amortized over the number of parts in one oven batch (see the formula for Oven Batch Size in Cycle Time for the Age Process).

A machine is considered feasible if the Calculated Oven Max Capacity is not 0.

aPriori selects only from preferred machines, if there is a feasible preferred machine and the cost model variable usePreferredMachines is set to true (the default in starting point Digital Factories). If there is no feasible preferred machine, or if the cost model variable usePreferredMachines is set to false, aPriori selects from all machines. A machine is preferred if the machine property isPreferred (typically displayed as Is Preferred) is true.

Feasibility and Routing for the Age Process

Age is automatically included in routings for Bar & Tube parts that use extruded stock. You can include it manually for other parts, as desired.

Age is feasible only if the current material does not have cut code 41, 42, 51, or 52.

Formulas for the Age Process

aPriori uses the formulas in the following sections to determine costs associated with this bending process:

Direct Overhead Cost for the Age Process

Direct Overhead Cost per Part =
((Labor Cost * Overhead Multiplier) + (Direct Overhead Rate * Cycle Time)) /
Final Yield

Direct overhead cost depends on the following:

Labor Cost for the Age Process

Labor Cost = (Labor Rate * Labor Time) / Final Yield

Labor cost depends on the following:

  • 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)

  • Labor time (see formula)

  • Final yield (see Heat Treatment Yields)

Labor Time = Racking Labor Time *
Number of Operators * Labor Time Standard

Labor time is the product of the following:

  • Racking labor time: see formula

  • Number of operators (specified by the machine property Number of Operators)

  • 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.

Racking Labor Time = 1 / Racking Rate

Racking labor time per part is the reciprocal of the racking rate, where the racking rate is the number of parts that can be racked or wired up per unit time. The racking rate is specified in parts per hour by one of the following cost model variables:

  • smallPartsRackingRatePerHr (200 per hour in starting point Digital Factories): for parts with mass less than the cost model variable smallPartsWeightLimit (2.25kg in starting point Digital Factories).

  • mediumPartsRackingRatePerHr (100 per hour in starting point Digital Factories): for parts with mass greater than or equal to smallPartsWeightLimit and less than mediumPartsWeightLimit (11.4kg in starting point Digital Factories).

  • largePartsRackingRatePerHr (50 per hour in starting point Digital Factories): for parts with mass greater than or equal to the value of the cost model variable mediumPartsWeightLimit.

The racking rate is converted to parts per second for use in this formula.

Cycle Time for the Age Process

Cycle Time = Process Time * Cycle Time Adjustment Factor

Cycle time depends on the following:

  • Process time: see formula.

  • Cycle time adjustment factor: specified by the cost model variable cycleTimeAdjustmentFactor (1 in starting point Digital Factories). Administrators can customize this value in order to globally adjust cycle times for Bar & Tube.

Process Time = Aging Time / Oven Batch Size

Process time is the time a batch of parts remains in the oven, amortized over the number of parts in the batch. It depends on the following:

  • Aging time: this is the time a batch of parts remains in the oven. By default, this is looked up by material type in the lookup table tblMaterialAgingTime. In starting point Digital Factories, aging time for all materials is listed as 7 hours. Administrators can modify the lookup table to provide times that vary by material.

    Note: Costing fails if the same material appears more than once in the lookup table.

If the current material is absent from the lookup table, default aging time is specified by the cost model variable defaultAgingTime (7 hours in starting point Digital Factories).

Users can override the default with the setup option Aging Time.

  • Oven batch size: by default, this is either the production batch size or the number of parts that can fit in the oven, whichever is smaller. See formula.

Oven Batch Size = min(Calculated Oven Max Capacity, Batch Size)

By default, oven batch size is either the production batch size or the number of parts that can fit in the oven, whichever is smaller. Default oven batch size depends on the following:

  • Calculated oven max capacity: see Calculated Oven Max Capacity.

  • Batch size: specified in the Production Scenario screen of the Cost Guide.

Users can override the default with the setup option Oven Batch Size.

Calculated Oven Max Capacity

The cost model determines the current machine’s maximum capacity by finding the most efficient of six possible orientations of the part within the oven container:

  • Part width aligned with oven width and part length aligned with oven length

  • Part width aligned with oven width and part height aligned with oven length

  • Part length aligned with oven width and part width aligned with oven length

  • Part length aligned with oven width and part height aligned with oven length

  • Part height aligned with oven width and part length aligned with oven length

  • Part height aligned with oven width and part width aligned with oven length

For each orientation, the cost model calculates the number of parts that fit in the oven container using a space allowance specified by the cost model variable agingPartNestingAlowance (13mm in starting point Digital Factories). The allowance is added to each dimension of each part.

The calculation assumes that part bounding boxes (supplemented by the nesting allowance) do not overlap.

Part length is given by the following geometric properties:

  • Sheet Metal parts: SER Length of the part’s blank

  • Bar & Tube parts: Length of the part’s cross section

  • All other parts: Length of the part

Part width is given by the following geometric properties:

  • Sheet Metal parts: SER Width of the part’s blank

  • Bar & Tube parts: Width or (if there is no Width) Outside Diameter of the part’s cross section

  • All other parts: Width of the part

Part width is given by the following geometric properties:

  • Sheet Metal parts: Thickness of the part’s blank

  • Bar & Tube parts: Height or (if there is no Height) Outside Diameter of the part’s cross section

  • All other parts: Height of the part

The oven container dimensions are given by the following machine properties:

  • Internal Width

  • Internal Length

  • Internal Height

Calculated oven max capacity drives cycle time; see Cycle Time for the Age Process.

Setup Options for the Age Process

The Age process provides the following option:

Aging Time

This is the time a batch of parts remains in the oven. By default, it is looked up by material type in the lookup table tblMaterialAgingTime. In starting point Digital Factories, aging time for all materials is listed as 7 hours. Administrators can modify the lookup table to provide times that vary by material.

Note: Costing fails if the same material appears more than once in the lookup table.

If the current material is absent from the lookup table, default aging time is specified by the cost model variable defaultAgingTime (7 hours in starting point Digital Factories).

Users can override the default with this setup option. Aging time drives cycle time; see Cycle Time for the Age Process.

Oven Batch Size

By default, oven batch size is either the production batch size or the number of parts that can fit in the oven, whichever is smaller. See Cycle Time for the Age Process. Users can override the default with this setup option.