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Item Sets and Attribute Tolerances

All nine machined parts are in one item class, CoreForge\WIP\Machined, but they belong to three families with different specs. An item set groups items when the item classes don't match the grouping you need. Each item can belong to only one item set.

Create the item sets
  1. Navigate to Configuration → Ops → Materials and confirm CoreForge\WIP\Machined contains CP-, PR- and SC- items in 2024, 6061 and 7075. If not, import items-coreforge-wip-machined.json.
  2. Navigate to Configuration → Quality → Item Sets and open the item set editor.
  3. Create three enabled item sets: Coupling Pins, Precision Rods and Shaft Cores.
  4. Link CP-2024, CP-6061 and CP-7075 to Coupling Pins, the PR- items to Precision Rods, and the SC- items to Shaft Cores.
Reference Materials: Item Sets

Product (Items) are naturally grouped in Item Classes. However it is possible that you may want to group a set of items that are in different classes when configuring check sheets that should only be enabled for a certain grouping of products. Item Sets can also be used to group together items that share a common set of tolerance specifications and the ability to do this really simplifies the management of tolerances rather than having to specify the same tolerances for every product you have.

Item Sets

Use the Item Sets to open up the Item Set Editor. you can add, edit and delete Item sets here.

Select any number of items and press the Item Sets to link these items together.

Note An item can only belong to one item set at a time, ensuring clarity in determining which tolerances apply.

From Item Sets →

An attribute is a named quality variable, such as a diameter, that check items can refer to. Its tolerances can be set per asset, item, item set, or for all items, so the check item doesn't need a hard-coded spec.

Create the FAI Diameter attribute
  1. Navigate to Configuration → Quality → Attributes and create the folders CoreForge and Machining, then an attribute FAI Diameter inside them.

  2. On its Tolerance tab, add one tolerance for each item set (all values in mm):

    Item setLELLSLLCLTargetUCLUSLUEL
    Coupling Pins9.859.909.9510.0010.0510.1010.15
    Precision Rods14.8014.8814.9415.0015.0615.1215.20
    Shaft Cores24.7024.8224.9125.0025.0925.1825.30
  3. Make sure each tolerance is enabled, and save.

A value between the control and spec limits passes but is highlighted as a warning. A value outside the spec limits (LSL/USL) fails. A value outside the entry limits (LEL/UEL) can't be entered.

Reference Materials: Attribute Tolerances

Tolerances​

One or more specifications (or tolerances) can be added to an attribute. A tolerance can be applied to all items by leaving the Asset, Item and Item Set fields blank. Otherwise, the Asset and Item selectors can be used to set tolerances by individual item, asset or item set. To add a new tolerance, click the

Add Tolerance button on the left of the Tolerance tab.

When a check is to be taken, it will first check if a tolerance exists for the current item. If no tolerance is found, it will check if the current item belongs to an item set that has a tolerance. If no item set tolerance has been configured, it will use the tolerance defined for all items.

Attributes

Tolerance Parameters

  • LEL Lower Entry Limit: Defines the minimum value that can be entered.
  • LSL Lower Spec Limit: Defines the lower Pass / Fail condition. Failing values will be highlighted red.
  • LCL Lower Control Limit: Defines the lower limit condition. Values below the LCL will be considered as passing but will be highlighted orange.
  • Target: Defines the expected ideal value
  • UCL Upper Control Limit: Defines the upper limit condition. Values exceeding the UCL will be considered as passing but will be highlighted orange.
  • USL - Upper Spec Limit: Defines the upper Pass / Fail condition. Failing values will be highlighted red.
  • UEL - Upper Entry Limit: Defines the maximum value that can be entered.
note

Tolerance parameter values must make logical sense or will be highlighted in red as a warning. For instance, the Upper Entry Limit cannot be smaller than the Lower Entry Limit.