diff --git a/src/components/Dashboard/common/ObjectChildTable.jsx b/src/components/Dashboard/common/ObjectChildTable.jsx
index 6269136..6c9d898 100644
--- a/src/components/Dashboard/common/ObjectChildTable.jsx
+++ b/src/components/Dashboard/common/ObjectChildTable.jsx
@@ -47,6 +47,7 @@ const createSkeletonRows = (rowCount, keyPrefix, keyName) => {
 
 const ObjectChildTable = ({
   maxWidth = '100%',
+  name,
   properties = [],
   columns = [],
   visibleColumns = {},
@@ -264,6 +265,17 @@ const ObjectChildTable = ({
   const rollupDataSource = useMemo(() => {
     if (!rollups || rollups.length === 0) return []
 
+    // Use value from form/props, or fall back to objectData when entering edit mode
+    // (form may not have populated the field yet)
+    const itemsForRollup =
+      value ?? (name && objectData ? objectData[name] : null) ?? []
+
+    // Build parent object with children array for rollup functions (e.g. objectData.parts)
+    const updatedObjectData = { ...objectData }
+    if (name) {
+      updatedObjectData[name] = itemsForRollup
+    }
+
     // Single summary row where each rollup value is placed under
     // the column that matches its `property` field.
     const summaryRow = {}
@@ -275,8 +287,6 @@ const ObjectChildTable = ({
 
       if (rollup && typeof rollup.value === 'function') {
         try {
-          const updatedObjectData = { ...objectData }
-          updatedObjectData[property.name] = value
           summaryRow[property.name] = rollup.value(updatedObjectData)
         } catch (e) {
           // Fail quietly but log for debugging
@@ -289,7 +299,7 @@ const ObjectChildTable = ({
     })
 
     return [summaryRow]
-  }, [properties, rollups, objectData, value])
+  }, [properties, rollups, objectData, value, name])
 
   const rollupColumns = useMemo(() => {
     const propertyColumns = properties.map((property, index) => {
@@ -455,6 +465,7 @@ const ObjectChildTable = ({
 }
 
 ObjectChildTable.propTypes = {
+  name: PropTypes.string,
   properties: PropTypes.arrayOf(
     PropTypes.shape({
       name: PropTypes.string.isRequired,
diff --git a/src/components/Dashboard/common/ObjectProperty.jsx b/src/components/Dashboard/common/ObjectProperty.jsx
index e1e3f93..e63072c 100644
--- a/src/components/Dashboard/common/ObjectProperty.jsx
+++ b/src/components/Dashboard/common/ObjectProperty.jsx
@@ -407,6 +407,7 @@ const ObjectProperty = ({
         case 'objectChildren': {
           return (
             <ObjectChildTable
+              name={name}
               value={value}
               properties={properties}
               objectData={objectData}
@@ -797,6 +798,7 @@ const ObjectProperty = ({
         case 'objectChildren': {
           return (
             <ObjectChildTable
+              name={name}
               properties={properties}
               objectData={objectData}
               isEditing={true}