Material Groups are configured in Pipeline LBM (PLBM) and referenced by the Takeoff workspace. If a Material Group is deleted in PLBM while still in use by active takeoffs, it can affect syncing and quantity behavior. This article explains what happens when Material Groups are deleted and how to work safely with existing takeoff data.

When a Material Group is deleted in PLBM:

• The group is no longer available for selection in PLBM.
• The Takeoff workspace may continue to display the Material Group for existing measurements.
• New takeoff measurements cannot reliably use the deleted group.

How the Takeoff workspace behaves after a Material Group is deleted

PTO does not immediately remove deleted Material Groups from existing takeoff data. This prevents sudden data loss but can cause sync issues if the group remains referenced.

Key behaviors:

• Existing measurements may still show the deleted Material Group.
• The group may appear selectable until the Takeoff workspace is refreshed.
• Syncing quantities that reference a deleted group may fail.

What happens during quantity sync

During sync, PLBM validates that each referenced Material Group exists and is active. If a takeoff measurement references a deleted Material Group, PLBM cannot accept the quantity.

As a result:

• The sync may fail with an error.
• Quantities for that Material Group are not updated in PLBM.
• Previously synced quantities remain unchanged until corrected.

Common scenarios

A Material Group is deleted while a job is active:

• Existing takeoff data continues to reference the deleted group.
• Sync fails until measurements are reassigned.

A Material Group is deleted after quantities were already synced:

• Existing quantities remain in PLBM.
• Future syncs may fail if deleted groups are still referenced.

How to resolve issues caused by deleted Material Groups

To restore successful syncing:

• Identify measurements using deleted Material Groups.
• Update those measurements to use an active Material Group.
• Refresh the Takeoff workspace.
• Sync quantities again.

What deleting a Material Group does not do

Deleting a Material Group does not:

• Delete existing takeoff measurements in the Takeoff workspace.
• Automatically remove quantities from PLBM.
• Delete jobs, products, or BOMs in PLBM.

Best practices

To avoid issues when managing Material Groups:

• Avoid deleting Material Groups used by active jobs.
• Coordinate configuration changes with estimators.
• Refresh the Takeoff workspace after Material Group changes in PLBM.
• Reassign takeoff data before syncing if groups are removed.