1. Using Product Development
  2. Rules About Item Structures

Rules About Item Structures

Here are some rules about item structures.

During the Item Lifecycle Phase

  • You can’t reinstate the parent item in a structure if the child component is marked obsolete.

  • You can assign an item in Draft approval status to an item structure.

  • A component's lifecycle phase should be the same or higher than the parent assembly's lifecycle phase; this applies to items of lifecycle phase Preproduction or Production only.

  • If an assembly is approved, components in the draft status can't be added. This applies to items of lifecycle phase Preproduction or Production only.

  • A hand-over of a structure to the downstream processes is triggered by changing the lifecycle phase of the parent item to Preproduction or Production.

When You Create Change Orders

  • You can edit an item without going through change management control, only if the item isn't assigned as an affected object to a change order.

  • If you're unable to add an item to a structure, here are some of the possible reasons:

    • There's another, later revision of the parent item.

    • The parent item is on a change order with a pending revision.

    • The item was earlier assigned to a change order and the change order is complete. So you're not allowed to modify the item's attributes, structure, AML, or attachments. To modify the item, assign it to a new change order.

    • The item is a duplicate component, or you’re adding a parent component to a child component.

      The restriction on adding a duplicate component doesn't apply if you opt in to the feature Add Find Number and Suggested Operation Sequence for Structure Components. This feature allows you to differentiate between multiple instances of a component within a structure using find numbers.

    • If the item is a commercial item, you can't add it to an engineering change order.

When You Deprecate Items

  • You can deprecate an item if it isn't used in another structure.

  • A child item can still be active if its parent is obsoleted.

  • A child item can't be obsoleted if the parent item is active.

To Calculate Item Grade

  • You can add items or other subassemblies to the top-level item. After you add the items, the grade of the top-level item must be refreshed. This results in a display of a newly calculated value of the grade.

  • The grade of the entire top-level assembly or item takes into account various statuses of the child items within the structure.

  • You must examine a structure to see which items don't have an AML or which ones have pending changes. Based on these conditions, you can decide to improve the grade, and then publish the item for manufacturing readiness.