diff --git a/api-v3/src/database/migrations/1790091000000-f6-solid-inventory-model.ts b/api-v3/src/database/migrations/1790091000000-f6-solid-inventory-model.ts
new file mode 100644
index 0000000..0a63dad
--- /dev/null
+++ b/api-v3/src/database/migrations/1790091000000-f6-solid-inventory-model.ts
@@ -0,0 +1,213 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+export class F6SolidInventoryModel1790091000000 implements MigrationInterface {
+  name = 'F6SolidInventoryModel1790091000000';
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    // A technical Subinstallation family may be valid under several Installation
+    // families. F3.1 used child_family_id as the PK, which made this relation
+    // accidentally one-to-one from the child's point of view.
+    await queryRunner.query(`
+      DO $$
+      DECLARE constraint_name text;
+      BEGIN
+        SELECT con.conname INTO constraint_name
+        FROM pg_constraint con
+        JOIN pg_class rel ON rel.oid=con.conrelid
+        WHERE rel.relname='inventory_family_parent_rules' AND con.contype='p'
+        LIMIT 1;
+        IF constraint_name IS NOT NULL THEN
+          EXECUTE format('ALTER TABLE inventory_family_parent_rules DROP CONSTRAINT %I',constraint_name);
+        END IF;
+      END $$;
+    `);
+    await queryRunner.query(`
+      ALTER TABLE inventory_family_parent_rules
+      ADD CONSTRAINT pk_inventory_family_parent_rules
+      PRIMARY KEY (child_family_id,parent_family_id)
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS idx_inventory_family_parent_rules_parent
+      ON inventory_family_parent_rules(parent_family_id,child_family_id)
+    `);
+
+    // Protect compatibility semantics at database level.
+    await queryRunner.query(`
+      CREATE OR REPLACE FUNCTION enforce_inventory_family_compatibility_rule()
+      RETURNS trigger LANGUAGE plpgsql AS $$
+      DECLARE child_level text; parent_level text;
+      BEGIN
+        SELECT level::text INTO child_level FROM inventory_families WHERE id=NEW.child_family_id;
+        SELECT level::text INTO parent_level FROM inventory_families WHERE id=NEW.parent_family_id;
+        IF child_level IS DISTINCT FROM 'SUBINSTALLATION' OR parent_level IS DISTINCT FROM 'INSTALLATION' THEN
+          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='La compatibilidad debe vincular Subinstalación con Instalación';
+        END IF;
+        RETURN NEW;
+      END $$;
+    `);
+    await queryRunner.query('DROP TRIGGER IF EXISTS trg_inventory_family_compatibility_rule ON inventory_family_parent_rules');
+    await queryRunner.query(`
+      CREATE TRIGGER trg_inventory_family_compatibility_rule
+      BEFORE INSERT OR UPDATE OF child_family_id,parent_family_id ON inventory_family_parent_rules
+      FOR EACH ROW EXECUTE FUNCTION enforce_inventory_family_compatibility_rule()
+    `);
+
+    // Family-specific technical fields. Generic asset type attributes remain for
+    // data genuinely shared by a whole structural level.
+    await queryRunner.query(`
+      CREATE TABLE IF NOT EXISTS inventory_family_attribute_definitions (
+        id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+        inventory_family_id uuid NOT NULL REFERENCES inventory_families(id) ON DELETE CASCADE,
+        code varchar(80) NOT NULL,
+        name varchar(160) NOT NULL,
+        data_type asset_attribute_data_type NOT NULL,
+        is_required boolean NOT NULL DEFAULT false,
+        is_active boolean NOT NULL DEFAULT true,
+        unit varchar(40) NULL,
+        options jsonb NULL,
+        sort_order integer NOT NULL DEFAULT 0,
+        created_by uuid NULL,
+        updated_by uuid NULL,
+        created_at timestamptz NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        updated_at timestamptz NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        CONSTRAINT uq_inventory_family_attribute_code UNIQUE(inventory_family_id,code),
+        CONSTRAINT chk_inventory_family_attribute_code CHECK (code ~ '^[a-z][a-z0-9_]*$'),
+        CONSTRAINT chk_inventory_family_attribute_options CHECK (
+          (data_type='SELECT' AND options IS NOT NULL AND jsonb_typeof(options)='array')
+          OR (data_type<>'SELECT')
+        )
+      )
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS idx_inventory_family_attributes_family
+      ON inventory_family_attribute_definitions(inventory_family_id,is_active,sort_order,name)
+    `);
+
+    await queryRunner.query(`
+      CREATE TABLE IF NOT EXISTS asset_inventory_attribute_values (
+        asset_id uuid NOT NULL REFERENCES assets(id) ON DELETE CASCADE,
+        definition_id uuid NOT NULL REFERENCES inventory_family_attribute_definitions(id) ON DELETE CASCADE,
+        value jsonb NOT NULL,
+        updated_by uuid NULL,
+        updated_at timestamptz NOT NULL DEFAULT CURRENT_TIMESTAMP,
+        PRIMARY KEY(asset_id,definition_id)
+      )
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS idx_asset_inventory_attribute_values_definition
+      ON asset_inventory_attribute_values(definition_id,asset_id)
+    `);
+
+    await queryRunner.query(`
+      CREATE OR REPLACE FUNCTION enforce_asset_inventory_attribute_family()
+      RETURNS trigger LANGUAGE plpgsql AS $$
+      DECLARE asset_family uuid; definition_family uuid;
+      BEGIN
+        SELECT inventory_family_id INTO asset_family FROM assets WHERE id=NEW.asset_id;
+        SELECT inventory_family_id INTO definition_family
+        FROM inventory_family_attribute_definitions WHERE id=NEW.definition_id AND is_active=true;
+        IF asset_family IS NULL OR definition_family IS NULL OR asset_family<>definition_family THEN
+          RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='El campo técnico no pertenece a la clasificación del Inventario';
+        END IF;
+        RETURN NEW;
+      END $$;
+    `);
+    await queryRunner.query('DROP TRIGGER IF EXISTS trg_asset_inventory_attribute_family ON asset_inventory_attribute_values');
+    await queryRunner.query(`
+      CREATE TRIGGER trg_asset_inventory_attribute_family
+      BEFORE INSERT OR UPDATE OF asset_id,definition_id ON asset_inventory_attribute_values
+      FOR EACH ROW EXECUTE FUNCTION enforce_asset_inventory_attribute_family()
+    `);
+
+    // Enforce classification level and Subinstallation compatibility on every
+    // physical Inventory write, not just through the current WEB/API.
+    await queryRunner.query(`
+      CREATE OR REPLACE FUNCTION enforce_f6_asset_family_contract()
+      RETURNS trigger LANGUAGE plpgsql AS $$
+      DECLARE child_type text; family_level text; parent_family uuid;
+      BEGIN
+        SELECT lower(code) INTO child_type FROM asset_types WHERE id=NEW.asset_type_id;
+
+        IF child_type IN ('departamento','area','yacimiento') THEN
+          IF NEW.inventory_family_id IS NOT NULL THEN
+            RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='Departamento, Área y Yacimiento no llevan clasificación técnica';
+          END IF;
+          RETURN NEW;
+        END IF;
+
+        IF child_type='instalacion' THEN
+          IF NEW.inventory_family_id IS NULL THEN
+            RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='La Instalación requiere clasificación técnica';
+          END IF;
+          SELECT level::text INTO family_level FROM inventory_families WHERE id=NEW.inventory_family_id AND is_active=true;
+          IF family_level IS DISTINCT FROM 'INSTALLATION' THEN
+            RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='La clasificación elegida no corresponde a una Instalación';
+          END IF;
+          RETURN NEW;
+        END IF;
+
+        IF child_type='subinstalacion' THEN
+          IF NEW.inventory_family_id IS NULL OR NEW.parent_id IS NULL THEN
+            RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='La Subinstalación requiere Instalación padre y clasificación técnica';
+          END IF;
+          SELECT level::text INTO family_level FROM inventory_families WHERE id=NEW.inventory_family_id AND is_active=true;
+          SELECT inventory_family_id INTO parent_family FROM assets WHERE id=NEW.parent_id;
+          IF family_level IS DISTINCT FROM 'SUBINSTALLATION' THEN
+            RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='La clasificación elegida no corresponde a una Subinstalación';
+          END IF;
+          IF parent_family IS NULL OR NOT EXISTS (
+            SELECT 1 FROM inventory_family_parent_rules rule
+            WHERE rule.child_family_id=NEW.inventory_family_id AND rule.parent_family_id=parent_family
+          ) THEN
+            RAISE EXCEPTION USING ERRCODE='23514',MESSAGE='La clasificación de Subinstalación no es compatible con la Instalación padre';
+          END IF;
+        END IF;
+        RETURN NEW;
+      END $$;
+    `);
+    await queryRunner.query('DROP TRIGGER IF EXISTS trg_f6_asset_family_contract ON assets');
+    await queryRunner.query(`
+      CREATE TRIGGER trg_f6_asset_family_contract
+      BEFORE INSERT OR UPDATE OF asset_type_id,parent_id,inventory_family_id ON assets
+      FOR EACH ROW EXECUTE FUNCTION enforce_f6_asset_family_contract()
+    `);
+
+    const [check] = (await queryRunner.query(`
+      SELECT
+        (SELECT COUNT(*)::integer FROM pg_constraint c JOIN pg_class r ON r.oid=c.conrelid
+          WHERE r.relname='inventory_family_parent_rules' AND c.contype='p'
+            AND pg_get_constraintdef(c.oid) LIKE '%child_family_id, parent_family_id%') AS composite_pk,
+        to_regclass('inventory_family_attribute_definitions') IS NOT NULL AS family_attributes,
+        to_regclass('asset_inventory_attribute_values') IS NOT NULL AS family_values
+    `)) as Array<{ composite_pk:number; family_attributes:boolean; family_values:boolean }>;
+    if (!check || Number(check.composite_pk)!==1 || !check.family_attributes || !check.family_values) {
+      throw new Error(`F6 inventory model verification failed: ${JSON.stringify(check ?? {})}`);
+    }
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query('DROP TRIGGER IF EXISTS trg_f6_asset_family_contract ON assets');
+    await queryRunner.query('DROP FUNCTION IF EXISTS enforce_f6_asset_family_contract()');
+    await queryRunner.query('DROP TRIGGER IF EXISTS trg_asset_inventory_attribute_family ON asset_inventory_attribute_values');
+    await queryRunner.query('DROP FUNCTION IF EXISTS enforce_asset_inventory_attribute_family()');
+    await queryRunner.query('DROP TABLE IF EXISTS asset_inventory_attribute_values');
+    await queryRunner.query('DROP TABLE IF EXISTS inventory_family_attribute_definitions');
+    await queryRunner.query('DROP TRIGGER IF EXISTS trg_inventory_family_compatibility_rule ON inventory_family_parent_rules');
+    await queryRunner.query('DROP FUNCTION IF EXISTS enforce_inventory_family_compatibility_rule()');
+    await queryRunner.query('DROP INDEX IF EXISTS idx_inventory_family_parent_rules_parent');
+
+    // Old schema allowed only one Installation family per Subinstallation family.
+    // Keep a deterministic first relation if F6 data must be rolled back.
+    await queryRunner.query(`
+      DELETE FROM inventory_family_parent_rules rule
+      USING inventory_family_parent_rules keep
+      WHERE rule.child_family_id=keep.child_family_id
+        AND rule.parent_family_id>keep.parent_family_id
+    `);
+    await queryRunner.query('ALTER TABLE inventory_family_parent_rules DROP CONSTRAINT IF EXISTS pk_inventory_family_parent_rules');
+    await queryRunner.query(`
+      ALTER TABLE inventory_family_parent_rules
+      ADD CONSTRAINT inventory_family_parent_rules_pkey PRIMARY KEY(child_family_id)
+    `);
+  }
+}