diff --git a/app/Services/WorkOrderService.php b/app/Services/WorkOrderService.php
index 62d44aa..d0ee318 100644
--- a/app/Services/WorkOrderService.php
+++ b/app/Services/WorkOrderService.php
@@ -1092,7 +1092,7 @@ public function updateItemStatus(int $workOrderId, int $itemId, string $status)
      * 작업지시에 필요한 자재 목록 조회 (BOM 기반 + 로트별 재고)
      *
      * 작업지시 품목의 BOM 자재별로 StockLot(입고 로트)를 FIFO 순서로 반환합니다.
-     * 로트번호는 입고관리(Receiving)에서 생성된 실제 로트번호입니다.
+     * 동일 자재가 여러 작업지시 품목에 걸쳐 있으면 필요수량을 합산하고 로트는 중복 없이 반환합니다.
      *
      * @param  int  $workOrderId  작업지시 ID
      * @return array 자재 목록 (로트 단위)
@@ -1109,8 +1109,8 @@ public function getMaterials(int $workOrderId): array
             throw new NotFoundHttpException(__('error.not_found'));
         }
 
-        $materials = [];
-        $rank = 1;
+        // Phase 1: 작업지시 품목들에서 유니크 자재 목록 수집 (item_id 기준 합산)
+        $uniqueMaterials = [];
 
         foreach ($workOrder->items as $woItem) {
             $materialItems = [];
@@ -1140,7 +1140,6 @@ public function getMaterials(int $workOrderId): array
                             'item' => $childItem,
                             'bom_qty' => $bomQty,
                             'required_qty' => $bomQty * ($woItem->quantity ?? 1),
-                            'work_order_item_id' => $woItem->id,
                         ];
                     }
                 }
@@ -1152,73 +1151,83 @@ public function getMaterials(int $workOrderId): array
                     'item' => $woItem->item,
                     'bom_qty' => 1,
                     'required_qty' => $woItem->quantity ?? 1,
-                    'work_order_item_id' => $woItem->id,
                 ];
             }
 
-            // 각 자재별로 StockLot(입고 로트) 조회
+            // 유니크 자재 수집 (같은 item_id면 required_qty 합산)
             foreach ($materialItems as $matInfo) {
-                $materialItem = $matInfo['item'];
-
-                // Stock 조회
-                $stock = \App\Models\Tenants\Stock::where('tenant_id', $tenantId)
-                    ->where('item_id', $materialItem->id)
-                    ->first();
-
-                if ($stock) {
-                    // 가용 로트를 FIFO 순서로 조회
-                    $lots = \App\Models\Tenants\StockLot::where('tenant_id', $tenantId)
-                        ->where('stock_id', $stock->id)
-                        ->where('status', 'available')
-                        ->where('available_qty', '>', 0)
-                        ->orderBy('fifo_order', 'asc')
-                        ->get();
-
-                    foreach ($lots as $lot) {
-                        $materials[] = [
-                            'stock_lot_id' => $lot->id,
-                            'item_id' => $materialItem->id,
-                            'work_order_item_id' => $matInfo['work_order_item_id'],
-                            'lot_no' => $lot->lot_no,
-                            'material_code' => $materialItem->code,
-                            'material_name' => $materialItem->name,
-                            'specification' => $materialItem->specification,
-                            'unit' => $lot->unit ?? $materialItem->unit ?? 'EA',
-                            'bom_qty' => $matInfo['bom_qty'],
-                            'required_qty' => $matInfo['required_qty'],
-                            'lot_qty' => (float) $lot->qty,
-                            'lot_available_qty' => (float) $lot->available_qty,
-                            'lot_reserved_qty' => (float) $lot->reserved_qty,
-                            'receipt_date' => $lot->receipt_date,
-                            'supplier' => $lot->supplier,
-                            'fifo_rank' => $rank++,
-                        ];
-                    }
+                $itemId = $matInfo['item']->id;
+                if (isset($uniqueMaterials[$itemId])) {
+                    $uniqueMaterials[$itemId]['required_qty'] += $matInfo['required_qty'];
+                } else {
+                    $uniqueMaterials[$itemId] = $matInfo;
                 }
+            }
+        }
 
-                // 가용 로트가 없는 경우 자재 정보만 반환 (재고 없음 표시)
-                $hasLots = collect($materials)->where('item_id', $materialItem->id)->isNotEmpty();
-                if (! $hasLots) {
+        // Phase 2: 유니크 자재별로 StockLot 조회
+        $materials = [];
+        $rank = 1;
+
+        foreach ($uniqueMaterials as $matInfo) {
+            $materialItem = $matInfo['item'];
+
+            $stock = \App\Models\Tenants\Stock::where('tenant_id', $tenantId)
+                ->where('item_id', $materialItem->id)
+                ->first();
+
+            $lotsFound = false;
+
+            if ($stock) {
+                $lots = \App\Models\Tenants\StockLot::where('tenant_id', $tenantId)
+                    ->where('stock_id', $stock->id)
+                    ->where('status', 'available')
+                    ->where('available_qty', '>', 0)
+                    ->orderBy('fifo_order', 'asc')
+                    ->get();
+
+                foreach ($lots as $lot) {
+                    $lotsFound = true;
                     $materials[] = [
-                        'stock_lot_id' => null,
+                        'stock_lot_id' => $lot->id,
                         'item_id' => $materialItem->id,
-                        'work_order_item_id' => $matInfo['work_order_item_id'],
-                        'lot_no' => null,
+                        'lot_no' => $lot->lot_no,
                         'material_code' => $materialItem->code,
                         'material_name' => $materialItem->name,
                         'specification' => $materialItem->specification,
-                        'unit' => $materialItem->unit ?? 'EA',
+                        'unit' => $lot->unit ?? $materialItem->unit ?? 'EA',
                         'bom_qty' => $matInfo['bom_qty'],
                         'required_qty' => $matInfo['required_qty'],
-                        'lot_qty' => 0,
-                        'lot_available_qty' => 0,
-                        'lot_reserved_qty' => 0,
-                        'receipt_date' => null,
-                        'supplier' => null,
+                        'lot_qty' => (float) $lot->qty,
+                        'lot_available_qty' => (float) $lot->available_qty,
+                        'lot_reserved_qty' => (float) $lot->reserved_qty,
+                        'receipt_date' => $lot->receipt_date,
+                        'supplier' => $lot->supplier,
                         'fifo_rank' => $rank++,
                     ];
                 }
             }
+
+            // 가용 로트가 없는 경우 자재 정보만 반환 (재고 없음 표시)
+            if (! $lotsFound) {
+                $materials[] = [
+                    'stock_lot_id' => null,
+                    'item_id' => $materialItem->id,
+                    'lot_no' => null,
+                    'material_code' => $materialItem->code,
+                    'material_name' => $materialItem->name,
+                    'specification' => $materialItem->specification,
+                    'unit' => $materialItem->unit ?? 'EA',
+                    'bom_qty' => $matInfo['bom_qty'],
+                    'required_qty' => $matInfo['required_qty'],
+                    'lot_qty' => 0,
+                    'lot_available_qty' => 0,
+                    'lot_reserved_qty' => 0,
+                    'receipt_date' => null,
+                    'supplier' => null,
+                    'fifo_rank' => $rank++,
+                ];
+            }
         }
 
         return $materials;