diff --git a/app/Http/Controllers/Api/V1/ItemMaster/ItemMasterFieldController.php b/app/Http/Controllers/Api/V1/ItemMaster/ItemMasterFieldController.php
deleted file mode 100644
index ff5e357..0000000
--- a/app/Http/Controllers/Api/V1/ItemMaster/ItemMasterFieldController.php
+++ /dev/null
@@ -1,58 +0,0 @@
-<?php
-
-namespace App\Http\Controllers\Api\V1\ItemMaster;
-
-use App\Http\Controllers\Controller;
-use App\Http\Requests\ItemMaster\ItemMasterFieldStoreRequest;
-use App\Http\Requests\ItemMaster\ItemMasterFieldUpdateRequest;
-use App\Helpers\ApiResponse;
-use App\Services\ItemMaster\ItemMasterFieldService;
-
-class ItemMasterFieldController extends Controller
-{
-    public function __construct(
-        protected ItemMasterFieldService $service,
-    ) {}
-
-    /**
-     * 마스터 필드 목록
-     */
-    public function index()
-    {
-        return ApiResponse::handle(function () {
-            return $this->service->index();
-        }, __('message.fetched'));
-    }
-
-    /**
-     * 마스터 필드 생성
-     */
-    public function store(ItemMasterFieldStoreRequest $request)
-    {
-        return ApiResponse::handle(function () use ($request) {
-            return $this->service->store($request->validated());
-        }, __('message.created'));
-    }
-
-    /**
-     * 마스터 필드 수정
-     */
-    public function update(int $id, ItemMasterFieldUpdateRequest $request)
-    {
-        return ApiResponse::handle(function () use ($id, $request) {
-            return $this->service->update($id, $request->validated());
-        }, __('message.updated'));
-    }
-
-    /**
-     * 마스터 필드 삭제
-     */
-    public function destroy(int $id)
-    {
-        return ApiResponse::handle(function () use ($id) {
-            $this->service->destroy($id);
-
-            return 'success';
-        }, __('message.deleted'));
-    }
-}
diff --git a/app/Http/Requests/ItemMaster/ItemBomItemStoreRequest.php b/app/Http/Requests/ItemMaster/ItemBomItemStoreRequest.php
index e1d10fe..9ab5557 100644
--- a/app/Http/Requests/ItemMaster/ItemBomItemStoreRequest.php
+++ b/app/Http/Requests/ItemMaster/ItemBomItemStoreRequest.php
@@ -14,6 +14,7 @@ public function authorize(): bool
     public function rules(): array
     {
         return [
+            'group_id' => 'nullable|integer|min:1', // 계층번호
             'item_code' => 'nullable|string|max:100',
             'item_name' => 'required|string|max:255',
             'quantity' => 'nullable|numeric|min:0',
diff --git a/app/Http/Requests/ItemMaster/ItemFieldStoreRequest.php b/app/Http/Requests/ItemMaster/ItemFieldStoreRequest.php
index e46f436..f728e8e 100644
--- a/app/Http/Requests/ItemMaster/ItemFieldStoreRequest.php
+++ b/app/Http/Requests/ItemMaster/ItemFieldStoreRequest.php
@@ -14,6 +14,7 @@ public function authorize(): bool
     public function rules(): array
     {
         return [
+            'group_id' => 'nullable|integer|min:1', // 계층번호
             'field_name' => 'required|string|max:255',
             'field_type' => 'required|in:textbox,number,dropdown,checkbox,date,textarea',
             'is_required' => 'nullable|boolean',
diff --git a/app/Http/Requests/ItemMaster/ItemMasterFieldStoreRequest.php b/app/Http/Requests/ItemMaster/ItemMasterFieldStoreRequest.php
deleted file mode 100644
index c59b55f..0000000
--- a/app/Http/Requests/ItemMaster/ItemMasterFieldStoreRequest.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-namespace App\Http\Requests\ItemMaster;
-
-use Illuminate\Foundation\Http\FormRequest;
-
-class ItemMasterFieldStoreRequest extends FormRequest
-{
-    public function authorize(): bool
-    {
-        return true;
-    }
-
-    public function rules(): array
-    {
-        return [
-            'field_name' => 'required|string|max:255',
-            'field_type' => 'required|in:textbox,number,dropdown,checkbox,date,textarea',
-            'category' => 'nullable|string|max:100',
-            'description' => 'nullable|string',
-            'is_common' => 'nullable|boolean',
-            'default_value' => 'nullable|string',
-            'options' => 'nullable|array',
-            'validation_rules' => 'nullable|array',
-            'properties' => 'nullable|array',
-        ];
-    }
-}
diff --git a/app/Http/Requests/ItemMaster/ItemMasterFieldUpdateRequest.php b/app/Http/Requests/ItemMaster/ItemMasterFieldUpdateRequest.php
deleted file mode 100644
index bfbfce3..0000000
--- a/app/Http/Requests/ItemMaster/ItemMasterFieldUpdateRequest.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-namespace App\Http\Requests\ItemMaster;
-
-use Illuminate\Foundation\Http\FormRequest;
-
-class ItemMasterFieldUpdateRequest extends FormRequest
-{
-    public function authorize(): bool
-    {
-        return true;
-    }
-
-    public function rules(): array
-    {
-        return [
-            'field_name' => 'sometimes|string|max:255',
-            'field_type' => 'sometimes|in:textbox,number,dropdown,checkbox,date,textarea',
-            'category' => 'sometimes|nullable|string|max:100',
-            'description' => 'sometimes|nullable|string',
-            'is_common' => 'sometimes|nullable|boolean',
-            'default_value' => 'sometimes|nullable|string',
-            'options' => 'sometimes|nullable|array',
-            'validation_rules' => 'sometimes|nullable|array',
-            'properties' => 'sometimes|nullable|array',
-        ];
-    }
-}
diff --git a/app/Http/Requests/ItemMaster/ItemSectionStoreRequest.php b/app/Http/Requests/ItemMaster/ItemSectionStoreRequest.php
index 968aa08..6a3fb6d 100644
--- a/app/Http/Requests/ItemMaster/ItemSectionStoreRequest.php
+++ b/app/Http/Requests/ItemMaster/ItemSectionStoreRequest.php
@@ -14,6 +14,7 @@ public function authorize(): bool
     public function rules(): array
     {
         return [
+            'group_id' => 'nullable|integer|min:1', // 계층번호
             'title' => 'required|string|max:255',
             'type' => 'required|in:fields,bom',
         ];
diff --git a/app/Models/ItemMaster/ItemBomItem.php b/app/Models/ItemMaster/ItemBomItem.php
index a1c9850..789c003 100644
--- a/app/Models/ItemMaster/ItemBomItem.php
+++ b/app/Models/ItemMaster/ItemBomItem.php
@@ -14,7 +14,6 @@ class ItemBomItem extends Model
     protected $fillable = [
         'tenant_id',
         'group_id',
-        'section_id',
         'item_code',
         'item_name',
         'quantity',
@@ -44,15 +43,7 @@ class ItemBomItem extends Model
     ];
 
     /**
-     * 소속 섹션 (기존 FK 기반 - 하위 호환성)
-     */
-    public function section()
-    {
-        return $this->belongsTo(ItemSection::class, 'section_id');
-    }
-
-    /**
-     * 이 BOM 항목이 연결된 섹션들 조회 (링크 테이블 기반)
+     * 이 BOM 항목이 연결된 섹션들 조회 (entity_relationships 기반)
      */
     public function linkedSections()
     {
diff --git a/app/Models/ItemMaster/ItemField.php b/app/Models/ItemMaster/ItemField.php
index c6bb740..682076d 100644
--- a/app/Models/ItemMaster/ItemField.php
+++ b/app/Models/ItemMaster/ItemField.php
@@ -14,7 +14,6 @@ class ItemField extends Model
     protected $fillable = [
         'tenant_id',
         'group_id',
-        'section_id',
         'field_name',
         'field_type',
         'order_no',
@@ -25,6 +24,9 @@ class ItemField extends Model
         'validation_rules',
         'options',
         'properties',
+        'category',
+        'description',
+        'is_common',
         'created_by',
         'updated_by',
         'deleted_by',
@@ -34,6 +36,7 @@ class ItemField extends Model
         'group_id' => 'integer',
         'order_no' => 'integer',
         'is_required' => 'boolean',
+        'is_common' => 'boolean',
         'display_condition' => 'array',
         'validation_rules' => 'array',
         'options' => 'array',
@@ -49,15 +52,7 @@ class ItemField extends Model
     ];
 
     /**
-     * 소속 섹션 (기존 FK 기반 - 하위 호환성)
-     */
-    public function section()
-    {
-        return $this->belongsTo(ItemSection::class, 'section_id');
-    }
-
-    /**
-     * 이 필드가 연결된 섹션들 조회 (링크 테이블 기반)
+     * 이 필드가 연결된 섹션들 조회 (entity_relationships 기반)
      */
     public function linkedSections()
     {
diff --git a/app/Models/ItemMaster/ItemMasterField.php b/app/Models/ItemMaster/ItemMasterField.php
deleted file mode 100644
index ca5e7f9..0000000
--- a/app/Models/ItemMaster/ItemMasterField.php
+++ /dev/null
@@ -1,46 +0,0 @@
-<?php
-
-namespace App\Models\ItemMaster;
-
-use App\Traits\BelongsToTenant;
-use App\Traits\ModelTrait;
-use Illuminate\Database\Eloquent\Model;
-use Illuminate\Database\Eloquent\SoftDeletes;
-
-class ItemMasterField extends Model
-{
-    use BelongsToTenant, ModelTrait, SoftDeletes;
-
-    protected $fillable = [
-        'tenant_id',
-        'group_id',
-        'field_name',
-        'field_type',
-        'category',
-        'description',
-        'is_common',
-        'default_value',
-        'options',
-        'validation_rules',
-        'properties',
-        'created_by',
-        'updated_by',
-        'deleted_by',
-    ];
-
-    protected $casts = [
-        'group_id' => 'integer',
-        'is_common' => 'boolean',
-        'options' => 'array',
-        'validation_rules' => 'array',
-        'properties' => 'array',
-        'created_at' => 'datetime',
-        'updated_at' => 'datetime',
-        'deleted_at' => 'datetime',
-    ];
-
-    protected $hidden = [
-        'deleted_by',
-        'deleted_at',
-    ];
-}
diff --git a/app/Models/ItemMaster/ItemSection.php b/app/Models/ItemMaster/ItemSection.php
index 6be472e..09b7984 100644
--- a/app/Models/ItemMaster/ItemSection.php
+++ b/app/Models/ItemMaster/ItemSection.php
@@ -14,7 +14,6 @@ class ItemSection extends Model
     protected $fillable = [
         'tenant_id',
         'group_id',
-        'page_id',
         'title',
         'type',
         'order_no',
@@ -58,27 +57,19 @@ public function scopeNonTemplates($query)
     ];
 
     /**
-     * 소속 페이지 (기존 FK 기반 - 하위 호환성)
-     */
-    public function page()
-    {
-        return $this->belongsTo(ItemPage::class, 'page_id');
-    }
-
-    /**
-     * 섹션의 필드 목록 (기존 FK 기반 - 하위 호환성)
+     * 섹션에 연결된 필드 목록 (entity_relationships 기반)
      */
     public function fields()
     {
-        return $this->hasMany(ItemField::class, 'section_id')->orderBy('order_no');
+        return $this->linkedFields();
     }
 
     /**
-     * 섹션의 BOM 항목 목록 (기존 FK 기반 - 하위 호환성)
+     * 섹션에 연결된 BOM 항목 목록 (entity_relationships 기반)
      */
     public function bomItems()
     {
-        return $this->hasMany(ItemBomItem::class, 'section_id');
+        return $this->linkedBomItems();
     }
 
     /**
diff --git a/app/Services/ItemMaster/ItemBomItemService.php b/app/Services/ItemMaster/ItemBomItemService.php
index 076c854..2a67d90 100644
--- a/app/Services/ItemMaster/ItemBomItemService.php
+++ b/app/Services/ItemMaster/ItemBomItemService.php
@@ -2,6 +2,7 @@
 
 namespace App\Services\ItemMaster;
 
+use App\Models\ItemMaster\EntityRelationship;
 use App\Models\ItemMaster\ItemBomItem;
 use App\Models\ItemMaster\ItemSection;
 use App\Services\Service;
@@ -37,7 +38,6 @@ public function storeIndependent(array $data): ItemBomItem
         $bomItem = ItemBomItem::create([
             'tenant_id' => $tenantId,
             'group_id' => $data['group_id'] ?? 1,
-            'section_id' => null,
             'item_code' => $data['item_code'] ?? null,
             'item_name' => $data['item_name'],
             'quantity' => $data['quantity'] ?? 1,
@@ -53,7 +53,7 @@ public function storeIndependent(array $data): ItemBomItem
     }
 
     /**
-     * BOM 항목 생성
+     * BOM 항목 생성 및 섹션에 연결
      */
     public function store(int $sectionId, array $data): ItemBomItem
     {
@@ -69,9 +69,10 @@ public function store(int $sectionId, array $data): ItemBomItem
             throw new NotFoundHttpException(__('error.not_found'));
         }
 
+        // BOM 항목 생성
         $bomItem = ItemBomItem::create([
             'tenant_id' => $tenantId,
-            'section_id' => $sectionId,
+            'group_id' => $data['group_id'] ?? 1,
             'item_code' => $data['item_code'] ?? null,
             'item_name' => $data['item_name'],
             'quantity' => $data['quantity'] ?? 1,
@@ -83,6 +84,17 @@ public function store(int $sectionId, array $data): ItemBomItem
             'created_by' => $userId,
         ]);
 
+        // 섹션-BOM 관계 생성
+        EntityRelationship::link(
+            EntityRelationship::TYPE_SECTION,
+            $sectionId,
+            EntityRelationship::TYPE_BOM,
+            $bomItem->id,
+            $tenantId,
+            $data['group_id'] ?? 1,
+            0
+        );
+
         return $bomItem;
     }
 
@@ -118,7 +130,9 @@ public function update(int $id, array $data): ItemBomItem
     }
 
     /**
-     * BOM 항목 삭제
+     * BOM 항목 삭제 (Soft Delete)
+     *
+     * 독립 엔티티 아키텍처: BOM 삭제 시 모든 부모 관계도 해제
      */
     public function destroy(int $id): void
     {
@@ -133,6 +147,13 @@ public function destroy(int $id): void
             throw new NotFoundHttpException(__('error.not_found'));
         }
 
+        // 1. entity_relationships에서 이 BOM의 모든 부모 관계 해제
+        //    (section→bom 관계에서 이 BOM 제거)
+        EntityRelationship::where('child_type', EntityRelationship::TYPE_BOM)
+            ->where('child_id', $id)
+            ->delete();
+
+        // 2. BOM Soft Delete
         $bomItem->update(['deleted_by' => $userId]);
         $bomItem->delete();
     }
diff --git a/app/Services/ItemMaster/ItemFieldService.php b/app/Services/ItemMaster/ItemFieldService.php
index 30c0f9c..b2052dc 100644
--- a/app/Services/ItemMaster/ItemFieldService.php
+++ b/app/Services/ItemMaster/ItemFieldService.php
@@ -11,7 +11,7 @@
 class ItemFieldService extends Service
 {
     /**
-     * 독립 필드 목록 조회
+     * 모든 필드 목록 조회
      *
      * GET /api/v1/item-master/fields
      */
@@ -37,7 +37,6 @@ public function storeIndependent(array $data): ItemField
         $field = ItemField::create([
             'tenant_id' => $tenantId,
             'group_id' => $data['group_id'] ?? 1,
-            'section_id' => null,
             'field_name' => $data['field_name'],
             'field_type' => $data['field_type'],
             'order_no' => 0,
@@ -48,6 +47,9 @@ public function storeIndependent(array $data): ItemField
             'validation_rules' => $data['validation_rules'] ?? null,
             'options' => $data['options'] ?? null,
             'properties' => $data['properties'] ?? null,
+            'category' => $data['category'] ?? null,
+            'description' => $data['description'] ?? null,
+            'is_common' => $data['is_common'] ?? false,
             'created_by' => $userId,
         ]);
 
@@ -75,7 +77,6 @@ public function clone(int $id): ItemField
         $cloned = ItemField::create([
             'tenant_id' => $tenantId,
             'group_id' => $original->group_id,
-            'section_id' => null,
             'field_name' => $original->field_name.' (복사본)',
             'field_type' => $original->field_type,
             'order_no' => 0,
@@ -86,6 +87,9 @@ public function clone(int $id): ItemField
             'validation_rules' => $original->validation_rules,
             'options' => $original->options,
             'properties' => $original->properties,
+            'category' => $original->category,
+            'description' => $original->description,
+            'is_common' => $original->is_common,
             'created_by' => $userId,
         ]);
 
@@ -109,48 +113,36 @@ public function getUsage(int $id): array
             throw new NotFoundHttpException(__('error.field_not_found'));
         }
 
-        // 1. 기존 FK 기반 연결 (section_id)
-        $directSection = $field->section;
-
-        // 2. entity_relationships 기반 연결 - 섹션
-        $linkedSectionIds = EntityRelationship::where('child_type', EntityRelationship::TYPE_FIELD)
-            ->where('child_id', $id)
-            ->where('parent_type', EntityRelationship::TYPE_SECTION)
-            ->pluck('parent_id')
-            ->toArray();
-
-        // 3. entity_relationships 기반 연결 - 페이지 (직접 연결)
-        $linkedPageIds = EntityRelationship::where('child_type', EntityRelationship::TYPE_FIELD)
-            ->where('child_id', $id)
-            ->where('parent_type', EntityRelationship::TYPE_PAGE)
-            ->pluck('parent_id')
-            ->toArray();
+        // entity_relationships 기반 연결
+        $linkedSections = $field->linkedSections()->get();
+        $linkedPages = $field->linkedPages()->get();
 
         return [
             'field_id' => $id,
-            'direct_section' => $directSection,
-            'linked_sections' => $field->linkedSections()->get(),
-            'linked_pages' => $field->linkedPages()->get(),
-            'total_usage_count' => ($directSection ? 1 : 0) + count($linkedSectionIds) + count($linkedPageIds),
+            'linked_sections' => $linkedSections,
+            'linked_pages' => $linkedPages,
+            'total_usage_count' => $linkedSections->count() + $linkedPages->count(),
         ];
     }
 
     /**
-     * 필드 생성
+     * 필드 생성 및 섹션에 연결
      */
     public function store(int $sectionId, array $data): ItemField
     {
         $tenantId = $this->tenantId();
         $userId = $this->apiUserId();
 
-        // order_no 자동 계산 (해당 섹션의 마지막 필드 + 1)
-        $maxOrder = ItemField::where('tenant_id', $tenantId)
-            ->where('section_id', $sectionId)
+        // order_no 자동 계산 (해당 섹션에 연결된 마지막 필드 + 1)
+        $maxOrder = EntityRelationship::where('parent_type', EntityRelationship::TYPE_SECTION)
+            ->where('parent_id', $sectionId)
+            ->where('child_type', EntityRelationship::TYPE_FIELD)
             ->max('order_no');
 
+        // 필드 생성
         $field = ItemField::create([
             'tenant_id' => $tenantId,
-            'section_id' => $sectionId,
+            'group_id' => $data['group_id'] ?? 1,
             'field_name' => $data['field_name'],
             'field_type' => $data['field_type'],
             'order_no' => ($maxOrder ?? -1) + 1,
@@ -164,6 +156,17 @@ public function store(int $sectionId, array $data): ItemField
             'created_by' => $userId,
         ]);
 
+        // 섹션-필드 관계 생성
+        EntityRelationship::link(
+            EntityRelationship::TYPE_SECTION,
+            $sectionId,
+            EntityRelationship::TYPE_FIELD,
+            $field->id,
+            $tenantId,
+            $data['group_id'] ?? 1,
+            ($maxOrder ?? -1) + 1
+        );
+
         return $field;
     }
 
@@ -193,6 +196,9 @@ public function update(int $id, array $data): ItemField
             'validation_rules' => $data['validation_rules'] ?? $field->validation_rules,
             'options' => $data['options'] ?? $field->options,
             'properties' => $data['properties'] ?? $field->properties,
+            'category' => $data['category'] ?? $field->category,
+            'description' => $data['description'] ?? $field->description,
+            'is_common' => $data['is_common'] ?? $field->is_common,
             'updated_by' => $userId,
         ]);
 
@@ -201,6 +207,8 @@ public function update(int $id, array $data): ItemField
 
     /**
      * 필드 삭제 (Soft Delete)
+     *
+     * 독립 엔티티 아키텍처: 필드 삭제 시 모든 부모 관계도 해제
      */
     public function destroy(int $id): void
     {
@@ -215,28 +223,35 @@ public function destroy(int $id): void
             throw new NotFoundHttpException(__('error.not_found'));
         }
 
+        // 1. entity_relationships에서 이 필드의 모든 부모 관계 해제
+        //    (section→field, page→field 관계에서 이 필드 제거)
+        EntityRelationship::where('child_type', EntityRelationship::TYPE_FIELD)
+            ->where('child_id', $id)
+            ->delete();
+
+        // 2. 필드 Soft Delete
         $field->update(['deleted_by' => $userId]);
         $field->delete();
     }
 
     /**
-     * 필드 순서 변경
+     * 필드 순서 변경 (entity_relationships 기반)
      *
      * @param  array  $items  [['id' => 1, 'order_no' => 0], ['id' => 2, 'order_no' => 1], ...]
      */
     public function reorder(int $sectionId, array $items): void
     {
-        $tenantId = $this->tenantId();
-        $userId = $this->apiUserId();
-
         foreach ($items as $item) {
-            ItemField::where('tenant_id', $tenantId)
-                ->where('section_id', $sectionId)
-                ->where('id', $item['id'])
-                ->update([
-                    'order_no' => $item['order_no'],
-                    'updated_by' => $userId,
-                ]);
+            // entity_relationships에서 순서 업데이트
+            EntityRelationship::where('parent_type', EntityRelationship::TYPE_SECTION)
+                ->where('parent_id', $sectionId)
+                ->where('child_type', EntityRelationship::TYPE_FIELD)
+                ->where('child_id', $item['id'])
+                ->update(['order_no' => $item['order_no']]);
+
+            // 필드 자체의 order_no도 동기화
+            ItemField::where('id', $item['id'])
+                ->update(['order_no' => $item['order_no']]);
         }
     }
 }
diff --git a/app/Services/ItemMaster/ItemMasterFieldService.php b/app/Services/ItemMaster/ItemMasterFieldService.php
deleted file mode 100644
index 490446b..0000000
--- a/app/Services/ItemMaster/ItemMasterFieldService.php
+++ /dev/null
@@ -1,101 +0,0 @@
-<?php
-
-namespace App\Services\ItemMaster;
-
-use App\Models\ItemMaster\ItemMasterField;
-use App\Services\Service;
-use Illuminate\Database\Eloquent\Collection;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
-
-class ItemMasterFieldService extends Service
-{
-    /**
-     * 마스터 필드 목록
-     */
-    public function index(): Collection
-    {
-        $tenantId = $this->tenantId();
-
-        return ItemMasterField::where('tenant_id', $tenantId)
-            ->orderBy('category')
-            ->orderBy('field_name')
-            ->get();
-    }
-
-    /**
-     * 마스터 필드 생성
-     */
-    public function store(array $data): ItemMasterField
-    {
-        $tenantId = $this->tenantId();
-        $userId = $this->apiUserId();
-
-        $field = ItemMasterField::create([
-            'tenant_id' => $tenantId,
-            'field_name' => $data['field_name'],
-            'field_type' => $data['field_type'],
-            'category' => $data['category'] ?? null,
-            'description' => $data['description'] ?? null,
-            'is_common' => $data['is_common'] ?? false,
-            'default_value' => $data['default_value'] ?? null,
-            'options' => $data['options'] ?? null,
-            'validation_rules' => $data['validation_rules'] ?? null,
-            'properties' => $data['properties'] ?? null,
-            'created_by' => $userId,
-        ]);
-
-        return $field;
-    }
-
-    /**
-     * 마스터 필드 수정
-     */
-    public function update(int $id, array $data): ItemMasterField
-    {
-        $tenantId = $this->tenantId();
-        $userId = $this->apiUserId();
-
-        $field = ItemMasterField::where('tenant_id', $tenantId)
-            ->where('id', $id)
-            ->first();
-
-        if (! $field) {
-            throw new NotFoundHttpException(__('error.not_found'));
-        }
-
-        $field->update([
-            'field_name' => $data['field_name'] ?? $field->field_name,
-            'field_type' => $data['field_type'] ?? $field->field_type,
-            'category' => $data['category'] ?? $field->category,
-            'description' => $data['description'] ?? $field->description,
-            'is_common' => $data['is_common'] ?? $field->is_common,
-            'default_value' => $data['default_value'] ?? $field->default_value,
-            'options' => $data['options'] ?? $field->options,
-            'validation_rules' => $data['validation_rules'] ?? $field->validation_rules,
-            'properties' => $data['properties'] ?? $field->properties,
-            'updated_by' => $userId,
-        ]);
-
-        return $field->fresh();
-    }
-
-    /**
-     * 마스터 필드 삭제
-     */
-    public function destroy(int $id): void
-    {
-        $tenantId = $this->tenantId();
-        $userId = $this->apiUserId();
-
-        $field = ItemMasterField::where('tenant_id', $tenantId)
-            ->where('id', $id)
-            ->first();
-
-        if (! $field) {
-            throw new NotFoundHttpException(__('error.not_found'));
-        }
-
-        $field->update(['deleted_by' => $userId]);
-        $field->delete();
-    }
-}
diff --git a/app/Services/ItemMaster/ItemPageService.php b/app/Services/ItemMaster/ItemPageService.php
index 4ab5223..14af2fe 100644
--- a/app/Services/ItemMaster/ItemPageService.php
+++ b/app/Services/ItemMaster/ItemPageService.php
@@ -2,6 +2,7 @@
 
 namespace App\Services\ItemMaster;
 
+use App\Models\ItemMaster\EntityRelationship;
 use App\Models\ItemMaster\ItemPage;
 use App\Services\Service;
 use Illuminate\Support\Collection;
@@ -87,6 +88,8 @@ public function update(int $id, array $data): ItemPage
 
     /**
      * 페이지 삭제 (Soft Delete)
+     *
+     * 독립 엔티티 아키텍처: 페이지만 삭제하고 연결된 섹션/필드는 unlink만 수행
      */
     public function destroy(int $id): void
     {
@@ -101,23 +104,14 @@ public function destroy(int $id): void
             throw new NotFoundHttpException(__('error.not_found'));
         }
 
+        // 1. entity_relationships에서 이 페이지의 모든 자식 관계 해제
+        //    (page→section, page→field 관계 삭제)
+        EntityRelationship::where('parent_type', EntityRelationship::TYPE_PAGE)
+            ->where('parent_id', $id)
+            ->delete();
+
+        // 2. 페이지만 Soft Delete (섹션/필드는 독립 엔티티로 유지)
         $page->update(['deleted_by' => $userId]);
         $page->delete();
-
-        // Cascade: 하위 섹션/필드도 Soft Delete
-        foreach ($page->sections as $section) {
-            $section->update(['deleted_by' => $userId]);
-            $section->delete();
-
-            foreach ($section->fields as $field) {
-                $field->update(['deleted_by' => $userId]);
-                $field->delete();
-            }
-
-            foreach ($section->bomItems as $bomItem) {
-                $bomItem->update(['deleted_by' => $userId]);
-                $bomItem->delete();
-            }
-        }
     }
 }
diff --git a/app/Services/ItemMaster/ItemSectionService.php b/app/Services/ItemMaster/ItemSectionService.php
index d8c2277..9dd71a7 100644
--- a/app/Services/ItemMaster/ItemSectionService.php
+++ b/app/Services/ItemMaster/ItemSectionService.php
@@ -13,7 +13,7 @@
 class ItemSectionService extends Service
 {
     /**
-     * 독립 섹션 목록 조회
+     * 모든 섹션 목록 조회
      *
      * GET /api/v1/item-master/sections
      */
@@ -21,8 +21,7 @@ public function index(?bool $isTemplate = null): Collection
     {
         $tenantId = $this->tenantId();
 
-        $query = ItemSection::where('tenant_id', $tenantId)
-            ->with(['fields', 'bomItems']);
+        $query = ItemSection::where('tenant_id', $tenantId);
 
         if ($isTemplate === true) {
             $query->templates();
@@ -46,7 +45,6 @@ public function storeIndependent(array $data): ItemSection
         $section = ItemSection::create([
             'tenant_id' => $tenantId,
             'group_id' => $data['group_id'] ?? 1,
-            'page_id' => null,
             'title' => $data['title'],
             'type' => $data['type'],
             'order_no' => 0,
@@ -82,7 +80,6 @@ public function clone(int $id): ItemSection
         $cloned = ItemSection::create([
             'tenant_id' => $tenantId,
             'group_id' => $original->group_id,
-            'page_id' => null,
             'title' => $original->title.' (복사본)',
             'type' => $original->type,
             'order_no' => 0,
@@ -150,46 +147,51 @@ public function getUsage(int $id): array
             throw new NotFoundHttpException(__('error.section_not_found'));
         }
 
-        // 1. 기존 FK 기반 연결 (page_id)
-        $directPage = $section->page;
-
-        // 2. entity_relationships 기반 연결
-        $linkedPageIds = EntityRelationship::where('child_type', EntityRelationship::TYPE_SECTION)
-            ->where('child_id', $id)
-            ->where('parent_type', EntityRelationship::TYPE_PAGE)
-            ->pluck('parent_id')
-            ->toArray();
+        // entity_relationships 기반 연결
+        $linkedPages = $section->linkedPages()->get();
 
         return [
             'section_id' => $id,
-            'direct_page' => $directPage,
-            'linked_pages' => $section->linkedPages()->get(),
-            'total_usage_count' => ($directPage ? 1 : 0) + count($linkedPageIds),
+            'linked_pages' => $linkedPages,
+            'total_usage_count' => $linkedPages->count(),
         ];
     }
 
     /**
-     * 섹션 생성
+     * 섹션 생성 및 페이지에 연결
      */
     public function store(int $pageId, array $data): ItemSection
     {
         $tenantId = $this->tenantId();
         $userId = $this->apiUserId();
 
-        // order_no 자동 계산 (해당 페이지의 마지막 섹션 + 1)
-        $maxOrder = ItemSection::where('tenant_id', $tenantId)
-            ->where('page_id', $pageId)
+        // order_no 자동 계산 (해당 페이지에 연결된 마지막 섹션 + 1)
+        $maxOrder = EntityRelationship::where('parent_type', EntityRelationship::TYPE_PAGE)
+            ->where('parent_id', $pageId)
+            ->where('child_type', EntityRelationship::TYPE_SECTION)
             ->max('order_no');
 
+        // 섹션 생성
         $section = ItemSection::create([
             'tenant_id' => $tenantId,
-            'page_id' => $pageId,
+            'group_id' => $data['group_id'] ?? 1,
             'title' => $data['title'],
             'type' => $data['type'],
             'order_no' => ($maxOrder ?? -1) + 1,
             'created_by' => $userId,
         ]);
 
+        // 페이지-섹션 관계 생성
+        EntityRelationship::link(
+            EntityRelationship::TYPE_PAGE,
+            $pageId,
+            EntityRelationship::TYPE_SECTION,
+            $section->id,
+            $tenantId,
+            $data['group_id'] ?? 1,
+            ($maxOrder ?? -1) + 1
+        );
+
         $section->load(['fields', 'bomItems']);
 
         return $section;
@@ -223,6 +225,8 @@ public function update(int $id, array $data): ItemSection
 
     /**
      * 섹션 삭제 (Soft Delete)
+     *
+     * 독립 엔티티 아키텍처: 섹션만 삭제하고 연결된 필드/BOM은 unlink만 수행
      */
     public function destroy(int $id): void
     {
@@ -237,39 +241,41 @@ public function destroy(int $id): void
             throw new NotFoundHttpException(__('error.not_found'));
         }
 
+        // 1. entity_relationships에서 이 섹션의 모든 부모 관계 해제
+        //    (page→section 관계에서 이 섹션 제거)
+        EntityRelationship::where('child_type', EntityRelationship::TYPE_SECTION)
+            ->where('child_id', $id)
+            ->delete();
+
+        // 2. entity_relationships에서 이 섹션의 모든 자식 관계 해제
+        //    (section→field, section→bom 관계 삭제)
+        EntityRelationship::where('parent_type', EntityRelationship::TYPE_SECTION)
+            ->where('parent_id', $id)
+            ->delete();
+
+        // 3. 섹션만 Soft Delete (필드/BOM은 독립 엔티티로 유지)
         $section->update(['deleted_by' => $userId]);
         $section->delete();
-
-        // Cascade: 하위 필드도 Soft Delete
-        foreach ($section->fields as $field) {
-            $field->update(['deleted_by' => $userId]);
-            $field->delete();
-        }
-
-        foreach ($section->bomItems as $bomItem) {
-            $bomItem->update(['deleted_by' => $userId]);
-            $bomItem->delete();
-        }
     }
 
     /**
-     * 섹션 순서 변경
+     * 섹션 순서 변경 (entity_relationships 기반)
      *
      * @param  array  $items  [['id' => 1, 'order_no' => 0], ['id' => 2, 'order_no' => 1], ...]
      */
     public function reorder(int $pageId, array $items): void
     {
-        $tenantId = $this->tenantId();
-        $userId = $this->apiUserId();
-
         foreach ($items as $item) {
-            ItemSection::where('tenant_id', $tenantId)
-                ->where('page_id', $pageId)
-                ->where('id', $item['id'])
-                ->update([
-                    'order_no' => $item['order_no'],
-                    'updated_by' => $userId,
-                ]);
+            // entity_relationships에서 순서 업데이트
+            EntityRelationship::where('parent_type', EntityRelationship::TYPE_PAGE)
+                ->where('parent_id', $pageId)
+                ->where('child_type', EntityRelationship::TYPE_SECTION)
+                ->where('child_id', $item['id'])
+                ->update(['order_no' => $item['order_no']]);
+
+            // 섹션 자체의 order_no도 동기화
+            ItemSection::where('id', $item['id'])
+                ->update(['order_no' => $item['order_no']]);
         }
     }
 }
diff --git a/app/Swagger/v1/ItemMasterApi.php b/app/Swagger/v1/ItemMasterApi.php
index 7567196..172fb5d 100644
--- a/app/Swagger/v1/ItemMasterApi.php
+++ b/app/Swagger/v1/ItemMasterApi.php
@@ -32,11 +32,11 @@
  * @OA\Schema(
  *   schema="ItemSection",
  *   type="object",
+ *   description="독립 엔티티 - 관계는 entity_relationships로 관리",
  *
  *   @OA\Property(property="id", type="integer", example=1),
  *   @OA\Property(property="tenant_id", type="integer", example=1),
- *   @OA\Property(property="group_id", type="integer", nullable=true, example=1),
- *   @OA\Property(property="page_id", type="integer", nullable=true, example=1),
+ *   @OA\Property(property="group_id", type="integer", nullable=true, example=1, description="계층번호"),
  *   @OA\Property(property="title", type="string", example="제품 상세"),
  *   @OA\Property(property="type", type="string", enum={"fields","bom"}, example="fields"),
  *   @OA\Property(property="order_no", type="integer", example=0),
@@ -63,10 +63,11 @@
  * @OA\Schema(
  *   schema="ItemField",
  *   type="object",
+ *   description="독립 엔티티 - 관계는 entity_relationships로 관리",
  *
  *   @OA\Property(property="id", type="integer", example=1),
  *   @OA\Property(property="tenant_id", type="integer", example=1),
- *   @OA\Property(property="section_id", type="integer", example=1),
+ *   @OA\Property(property="group_id", type="integer", nullable=true, example=1, description="계층번호"),
  *   @OA\Property(property="field_name", type="string", example="제품명"),
  *   @OA\Property(property="field_type", type="string", enum={"textbox","number","dropdown","checkbox","date","textarea"}, example="textbox"),
  *   @OA\Property(property="order_no", type="integer", example=0),
@@ -77,6 +78,9 @@
  *   @OA\Property(property="validation_rules", type="object", nullable=true, example=null),
  *   @OA\Property(property="options", type="object", nullable=true, example=null),
  *   @OA\Property(property="properties", type="object", nullable=true, example=null),
+ *   @OA\Property(property="category", type="string", nullable=true, example="basic", description="필드 카테고리"),
+ *   @OA\Property(property="description", type="string", nullable=true, example="필드 설명"),
+ *   @OA\Property(property="is_common", type="boolean", example=false, description="공통 필드 여부"),
  *   @OA\Property(property="created_at", type="string", example="2025-11-20 10:00:00"),
  *   @OA\Property(property="updated_at", type="string", example="2025-11-20 10:00:00")
  * )
@@ -84,10 +88,11 @@
  * @OA\Schema(
  *   schema="ItemBomItem",
  *   type="object",
+ *   description="독립 엔티티 - 관계는 entity_relationships로 관리",
  *
  *   @OA\Property(property="id", type="integer", example=1),
  *   @OA\Property(property="tenant_id", type="integer", example=1),
- *   @OA\Property(property="section_id", type="integer", example=1),
+ *   @OA\Property(property="group_id", type="integer", nullable=true, example=1, description="계층번호"),
  *   @OA\Property(property="item_code", type="string", nullable=true, example="ITEM001"),
  *   @OA\Property(property="item_name", type="string", example="부품 A"),
  *   @OA\Property(property="quantity", type="number", format="float", example=1.5),
@@ -115,25 +120,6 @@
  * )
  *
  * @OA\Schema(
- *   schema="ItemMasterField",
- *   type="object",
- *
- *   @OA\Property(property="id", type="integer", example=1),
- *   @OA\Property(property="tenant_id", type="integer", example=1),
- *   @OA\Property(property="field_name", type="string", example="제품명"),
- *   @OA\Property(property="field_type", type="string", enum={"textbox","number","dropdown","checkbox","date","textarea"}, example="textbox"),
- *   @OA\Property(property="category", type="string", nullable=true, example="basic"),
- *   @OA\Property(property="description", type="string", nullable=true, example="설명"),
- *   @OA\Property(property="is_common", type="boolean", example=true),
- *   @OA\Property(property="default_value", type="string", nullable=true, example=null),
- *   @OA\Property(property="options", type="object", nullable=true, example=null),
- *   @OA\Property(property="validation_rules", type="object", nullable=true, example=null),
- *   @OA\Property(property="properties", type="object", nullable=true, example=null),
- *   @OA\Property(property="created_at", type="string", example="2025-11-20 10:00:00"),
- *   @OA\Property(property="updated_at", type="string", example="2025-11-20 10:00:00")
- * )
- *
- * @OA\Schema(
  *   schema="CustomTab",
  *   type="object",
  *
@@ -187,6 +173,7 @@
  *   type="object",
  *   required={"title","type"},
  *
+ *   @OA\Property(property="group_id", type="integer", nullable=true, example=1, description="계층번호"),
  *   @OA\Property(property="title", type="string", maxLength=255, example="제품 상세"),
  *   @OA\Property(property="type", type="string", enum={"fields","bom"}, example="fields")
  * )
@@ -196,7 +183,7 @@
  *   type="object",
  *   required={"title","type"},
  *
- *   @OA\Property(property="group_id", type="integer", nullable=true, example=1),
+ *   @OA\Property(property="group_id", type="integer", nullable=true, example=1, description="계층번호"),
  *   @OA\Property(property="title", type="string", maxLength=255, example="독립 섹션"),
  *   @OA\Property(property="type", type="string", enum={"fields","bom"}, example="fields"),
  *   @OA\Property(property="is_template", type="boolean", example=false),
@@ -209,7 +196,7 @@
  *   type="object",
  *   required={"field_name","field_type"},
  *
- *   @OA\Property(property="group_id", type="integer", nullable=true, example=1),
+ *   @OA\Property(property="group_id", type="integer", nullable=true, example=1, description="계층번호"),
  *   @OA\Property(property="field_name", type="string", maxLength=255, example="제품명"),
  *   @OA\Property(property="field_type", type="string", enum={"textbox","number","dropdown","checkbox","date","textarea"}, example="textbox"),
  *   @OA\Property(property="is_required", type="boolean", example=false),
@@ -226,7 +213,7 @@
  *   type="object",
  *   required={"item_name"},
  *
- *   @OA\Property(property="group_id", type="integer", nullable=true, example=1),
+ *   @OA\Property(property="group_id", type="integer", nullable=true, example=1, description="계층번호"),
  *   @OA\Property(property="item_code", type="string", nullable=true, maxLength=100, example="ITEM001"),
  *   @OA\Property(property="item_name", type="string", maxLength=255, example="부품 A"),
  *   @OA\Property(property="quantity", type="number", format="float", example=1),
@@ -240,9 +227,9 @@
  * @OA\Schema(
  *   schema="SectionUsageResponse",
  *   type="object",
+ *   description="섹션 사용처 응답 (entity_relationships 기반)",
  *
  *   @OA\Property(property="section_id", type="integer", example=1),
- *   @OA\Property(property="direct_page", type="object", nullable=true),
  *   @OA\Property(property="linked_pages", type="array", @OA\Items(type="object")),
  *   @OA\Property(property="total_usage_count", type="integer", example=2)
  * )
@@ -250,9 +237,9 @@
  * @OA\Schema(
  *   schema="FieldUsageResponse",
  *   type="object",
+ *   description="필드 사용처 응답 (entity_relationships 기반)",
  *
  *   @OA\Property(property="field_id", type="integer", example=1),
- *   @OA\Property(property="direct_section", type="object", nullable=true),
  *   @OA\Property(property="linked_sections", type="array", @OA\Items(type="object")),
  *   @OA\Property(property="linked_pages", type="array", @OA\Items(type="object")),
  *   @OA\Property(property="total_usage_count", type="integer", example=3)
@@ -270,6 +257,7 @@
  *   type="object",
  *   required={"field_name","field_type"},
  *
+ *   @OA\Property(property="group_id", type="integer", nullable=true, example=1, description="계층번호"),
  *   @OA\Property(property="field_name", type="string", maxLength=255, example="제품명"),
  *   @OA\Property(property="field_type", type="string", enum={"textbox","number","dropdown","checkbox","date","textarea"}, example="textbox"),
  *   @OA\Property(property="is_required", type="boolean", example=true),
@@ -301,6 +289,7 @@
  *   type="object",
  *   required={"item_name"},
  *
+ *   @OA\Property(property="group_id", type="integer", nullable=true, example=1, description="계층번호"),
  *   @OA\Property(property="item_code", type="string", nullable=true, maxLength=100, example="ITEM001"),
  *   @OA\Property(property="item_name", type="string", maxLength=255, example="부품 A"),
  *   @OA\Property(property="quantity", type="number", format="float", example=1.5),
@@ -348,37 +337,6 @@
  * )
  *
  * @OA\Schema(
- *   schema="ItemMasterFieldStoreRequest",
- *   type="object",
- *   required={"field_name","field_type"},
- *
- *   @OA\Property(property="field_name", type="string", maxLength=255, example="제품명"),
- *   @OA\Property(property="field_type", type="string", enum={"textbox","number","dropdown","checkbox","date","textarea"}, example="textbox"),
- *   @OA\Property(property="category", type="string", nullable=true, maxLength=100, example="basic"),
- *   @OA\Property(property="description", type="string", nullable=true, example="설명"),
- *   @OA\Property(property="is_common", type="boolean", example=true),
- *   @OA\Property(property="default_value", type="string", nullable=true, example=null),
- *   @OA\Property(property="options", type="object", nullable=true, example=null),
- *   @OA\Property(property="validation_rules", type="object", nullable=true, example=null),
- *   @OA\Property(property="properties", type="object", nullable=true, example=null)
- * )
- *
- * @OA\Schema(
- *   schema="ItemMasterFieldUpdateRequest",
- *   type="object",
- *
- *   @OA\Property(property="field_name", type="string", maxLength=255, example="제품명"),
- *   @OA\Property(property="field_type", type="string", enum={"textbox","number","dropdown","checkbox","date","textarea"}, example="textbox"),
- *   @OA\Property(property="category", type="string", nullable=true, maxLength=100, example="basic"),
- *   @OA\Property(property="description", type="string", nullable=true, example="설명"),
- *   @OA\Property(property="is_common", type="boolean", example=true),
- *   @OA\Property(property="default_value", type="string", nullable=true, example=null),
- *   @OA\Property(property="options", type="object", nullable=true, example=null),
- *   @OA\Property(property="validation_rules", type="object", nullable=true, example=null),
- *   @OA\Property(property="properties", type="object", nullable=true, example=null)
- * )
- *
- * @OA\Schema(
  *   schema="CustomTabStoreRequest",
  *   type="object",
  *   required={"label"},
@@ -451,13 +409,6 @@
  *   ),
  *
  *   @OA\Property(
- *     property="masterFields",
- *     type="array",
- *
- *     @OA\Items(ref="#/components/schemas/ItemMasterField")
- *   ),
- *
- *   @OA\Property(
  *     property="customTabs",
  *     type="array",
  *
@@ -570,7 +521,8 @@ public function updatePages() {}
      * @OA\Delete(
      *   path="/api/v1/item-master/pages/{id}",
      *   tags={"ItemMaster"},
-     *   summary="페이지 삭제 (Cascade)",
+     *   summary="페이지 삭제",
+     *   description="페이지를 삭제합니다. 연결된 섹션/필드는 삭제되지 않고 관계만 해제됩니다.",
      *   security={{"ApiKeyAuth":{}},{"BearerAuth":{}}},
      *
      *   @OA\Parameter(name="id", in="path", required=true, @OA\Schema(type="integer")),
@@ -658,7 +610,7 @@ public function cloneSection() {}
      *   path="/api/v1/item-master/sections/{id}/usage",
      *   tags={"ItemMaster"},
      *   summary="섹션 사용처 조회",
-     *   description="섹션이 어떤 페이지에 연결되어 있는지 조회합니다. FK 기반 연결과 entity_relationships 기반 연결 모두 조회됩니다.",
+     *   description="섹션이 어떤 페이지에 연결되어 있는지 조회합니다 (entity_relationships 기반).",
      *   security={{"ApiKeyAuth":{}},{"BearerAuth":{}}},
      *
      *   @OA\Parameter(name="id", in="path", required=true, description="섹션 ID", @OA\Schema(type="integer")),
@@ -871,7 +823,8 @@ public function updateSections() {}
      * @OA\Delete(
      *   path="/api/v1/item-master/sections/{id}",
      *   tags={"ItemMaster"},
-     *   summary="섹션 삭제 (Cascade)",
+     *   summary="섹션 삭제",
+     *   description="섹션을 삭제합니다. 연결된 필드/BOM은 삭제되지 않고 관계만 해제됩니다.",
      *   security={{"ApiKeyAuth":{}},{"BearerAuth":{}}},
      *
      *   @OA\Parameter(name="id", in="path", required=true, @OA\Schema(type="integer")),
@@ -1130,90 +1083,6 @@ public function updateSectionTemplates() {}
      */
     public function destroySectionTemplates() {}
 
-    /**
-     * @OA\Get(
-     *   path="/api/v1/item-master/master-fields",
-     *   tags={"ItemMaster"},
-     *   summary="마스터 필드 목록",
-     *   security={{"ApiKeyAuth":{}},{"BearerAuth":{}}},
-     *
-     *   @OA\Response(response=200, description="조회 성공",
-     *
-     *     @OA\JsonContent(allOf={
-     *
-     *       @OA\Schema(ref="#/components/schemas/ApiResponse"),
-     *       @OA\Schema(@OA\Property(property="data", type="array", @OA\Items(ref="#/components/schemas/ItemMasterField")))
-     *     })
-     *   ),
-     *
-     *   @OA\Response(response=401, description="인증 실패", @OA\JsonContent(ref="#/components/schemas/ErrorResponse"))
-     * )
-     */
-    public function indexMasterFields() {}
-
-    /**
-     * @OA\Post(
-     *   path="/api/v1/item-master/master-fields",
-     *   tags={"ItemMaster"},
-     *   summary="마스터 필드 생성",
-     *   security={{"ApiKeyAuth":{}},{"BearerAuth":{}}},
-     *
-     *   @OA\RequestBody(required=true, @OA\JsonContent(ref="#/components/schemas/ItemMasterFieldStoreRequest")),
-     *
-     *   @OA\Response(response=200, description="생성 성공",
-     *
-     *     @OA\JsonContent(allOf={
-     *
-     *       @OA\Schema(ref="#/components/schemas/ApiResponse"),
-     *       @OA\Schema(@OA\Property(property="data", ref="#/components/schemas/ItemMasterField"))
-     *     })
-     *   ),
-     *
-     *   @OA\Response(response=422, description="검증 실패", @OA\JsonContent(ref="#/components/schemas/ErrorResponse"))
-     * )
-     */
-    public function storeMasterFields() {}
-
-    /**
-     * @OA\Put(
-     *   path="/api/v1/item-master/master-fields/{id}",
-     *   tags={"ItemMaster"},
-     *   summary="마스터 필드 수정",
-     *   security={{"ApiKeyAuth":{}},{"BearerAuth":{}}},
-     *
-     *   @OA\Parameter(name="id", in="path", required=true, @OA\Schema(type="integer")),
-     *
-     *   @OA\RequestBody(required=true, @OA\JsonContent(ref="#/components/schemas/ItemMasterFieldUpdateRequest")),
-     *
-     *   @OA\Response(response=200, description="수정 성공",
-     *
-     *     @OA\JsonContent(allOf={
-     *
-     *       @OA\Schema(ref="#/components/schemas/ApiResponse"),
-     *       @OA\Schema(@OA\Property(property="data", ref="#/components/schemas/ItemMasterField"))
-     *     })
-     *   ),
-     *
-     *   @OA\Response(response=404, description="데이터 없음", @OA\JsonContent(ref="#/components/schemas/ErrorResponse"))
-     * )
-     */
-    public function updateMasterFields() {}
-
-    /**
-     * @OA\Delete(
-     *   path="/api/v1/item-master/master-fields/{id}",
-     *   tags={"ItemMaster"},
-     *   summary="마스터 필드 삭제",
-     *   security={{"ApiKeyAuth":{}},{"BearerAuth":{}}},
-     *
-     *   @OA\Parameter(name="id", in="path", required=true, @OA\Schema(type="integer")),
-     *
-     *   @OA\Response(response=200, description="삭제 성공", @OA\JsonContent(ref="#/components/schemas/ApiResponse")),
-     *   @OA\Response(response=404, description="데이터 없음", @OA\JsonContent(ref="#/components/schemas/ErrorResponse"))
-     * )
-     */
-    public function destroyMasterFields() {}
-
     /**
      * @OA\Get(
      *   path="/api/v1/item-master/custom-tabs",
diff --git a/database/migrations/2025_11_27_090523_drop_item_master_fields_table.php b/database/migrations/2025_11_27_090523_drop_item_master_fields_table.php
new file mode 100644
index 0000000..19e2204
--- /dev/null
+++ b/database/migrations/2025_11_27_090523_drop_item_master_fields_table.php
@@ -0,0 +1,31 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Support\Facades\Schema;
+
+/**
+ * item_master_fields 테이블 삭제
+ *
+ * 이유: item_fields로 통합 완료 (2025_11_26_230132 마이그레이션)
+ * - 데이터는 이미 item_fields로 이관됨
+ * - 관련 Model, Service, Controller도 함께 삭제
+ */
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::dropIfExists('item_master_fields');
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        // 테이블 복원이 필요한 경우 2025_11_20_100002 마이그레이션 참조
+        // 데이터는 복원 불가
+    }
+};
diff --git a/database/migrations/2025_11_27_092448_remove_fk_columns_from_item_tables.php b/database/migrations/2025_11_27_092448_remove_fk_columns_from_item_tables.php
new file mode 100644
index 0000000..3cb05a1
--- /dev/null
+++ b/database/migrations/2025_11_27_092448_remove_fk_columns_from_item_tables.php
@@ -0,0 +1,156 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+/**
+ * FK 컬럼 제거 마이그레이션
+ *
+ * 목적: 모든 엔티티를 완전히 독립적으로 만들고, 관계는 entity_relationships로만 관리
+ *
+ * 제거 대상:
+ * - item_sections.page_id
+ * - item_fields.section_id
+ * - item_bom_items.section_id
+ *
+ * 데이터 이관:
+ * - 기존 FK 데이터는 entity_relationships로 이관 후 컬럼 삭제
+ */
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        // 1. item_sections.page_id → entity_relationships 이관
+        $sections = DB::table('item_sections')
+            ->whereNotNull('page_id')
+            ->whereNull('deleted_at')
+            ->get();
+
+        foreach ($sections as $section) {
+            DB::table('entity_relationships')->insertOrIgnore([
+                'tenant_id' => $section->tenant_id,
+                'group_id' => $section->group_id ?? 1,
+                'parent_type' => 'page',
+                'parent_id' => $section->page_id,
+                'child_type' => 'section',
+                'child_id' => $section->id,
+                'order_no' => $section->order_no ?? 0,
+                'created_at' => now(),
+                'updated_at' => now(),
+            ]);
+        }
+
+        // 2. item_fields.section_id → entity_relationships 이관
+        $fields = DB::table('item_fields')
+            ->whereNotNull('section_id')
+            ->whereNull('deleted_at')
+            ->get();
+
+        foreach ($fields as $field) {
+            DB::table('entity_relationships')->insertOrIgnore([
+                'tenant_id' => $field->tenant_id,
+                'group_id' => $field->group_id ?? 1,
+                'parent_type' => 'section',
+                'parent_id' => $field->section_id,
+                'child_type' => 'field',
+                'child_id' => $field->id,
+                'order_no' => $field->order_no ?? 0,
+                'created_at' => now(),
+                'updated_at' => now(),
+            ]);
+        }
+
+        // 3. item_bom_items.section_id → entity_relationships 이관
+        $bomItems = DB::table('item_bom_items')
+            ->whereNotNull('section_id')
+            ->whereNull('deleted_at')
+            ->get();
+
+        foreach ($bomItems as $bom) {
+            DB::table('entity_relationships')->insertOrIgnore([
+                'tenant_id' => $bom->tenant_id,
+                'group_id' => $bom->group_id ?? 1,
+                'parent_type' => 'section',
+                'parent_id' => $bom->section_id,
+                'child_type' => 'bom',
+                'child_id' => $bom->id,
+                'order_no' => 0,
+                'created_at' => now(),
+                'updated_at' => now(),
+            ]);
+        }
+
+        // 4. FK 컬럼 삭제
+        Schema::table('item_sections', function (Blueprint $table) {
+            $table->dropColumn('page_id');
+        });
+
+        Schema::table('item_fields', function (Blueprint $table) {
+            $table->dropColumn('section_id');
+        });
+
+        Schema::table('item_bom_items', function (Blueprint $table) {
+            $table->dropColumn('section_id');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        // 1. FK 컬럼 복원
+        Schema::table('item_sections', function (Blueprint $table) {
+            $table->unsignedBigInteger('page_id')->nullable()->after('group_id')->comment('페이지 ID');
+        });
+
+        Schema::table('item_fields', function (Blueprint $table) {
+            $table->unsignedBigInteger('section_id')->nullable()->after('group_id')->comment('섹션 ID');
+        });
+
+        Schema::table('item_bom_items', function (Blueprint $table) {
+            $table->unsignedBigInteger('section_id')->nullable()->after('group_id')->comment('섹션 ID');
+        });
+
+        // 2. entity_relationships → FK 복원 (page-section)
+        $pageRelations = DB::table('entity_relationships')
+            ->where('parent_type', 'page')
+            ->where('child_type', 'section')
+            ->get();
+
+        foreach ($pageRelations as $rel) {
+            DB::table('item_sections')
+                ->where('id', $rel->child_id)
+                ->update(['page_id' => $rel->parent_id]);
+        }
+
+        // 3. entity_relationships → FK 복원 (section-field)
+        $fieldRelations = DB::table('entity_relationships')
+            ->where('parent_type', 'section')
+            ->where('child_type', 'field')
+            ->get();
+
+        foreach ($fieldRelations as $rel) {
+            DB::table('item_fields')
+                ->where('id', $rel->child_id)
+                ->update(['section_id' => $rel->parent_id]);
+        }
+
+        // 4. entity_relationships → FK 복원 (section-bom)
+        $bomRelations = DB::table('entity_relationships')
+            ->where('parent_type', 'section')
+            ->where('child_type', 'bom')
+            ->get();
+
+        foreach ($bomRelations as $rel) {
+            DB::table('item_bom_items')
+                ->where('id', $rel->child_id)
+                ->update(['section_id' => $rel->parent_id]);
+        }
+    }
+};