diff --git a/app/Http/Controllers/Admin/Inventory/ProductionController.php b/app/Http/Controllers/Admin/Inventory/ProductionController.php
index 6c598fa..219a136 100644
--- a/app/Http/Controllers/Admin/Inventory/ProductionController.php
+++ b/app/Http/Controllers/Admin/Inventory/ProductionController.php
@@ -155,8 +155,22 @@ class ProductionController extends Controller
 
         $defaultLocationId = $production->location_id;
 
+        // N-04 (Nachprüfung 08.09.2026): Bei gebuchter Produktion zeigt die Vorschau den
+        // gespeicherten Verpackungs-Snapshot, solange die Ergebnissummen unverändert sind
+        // (dieselbe Regel wie ProductionService::updateProduction, F-05).
+        $production->loadMissing('productionPackagings.packagingItem');
+        $packagingSnapshot = $production->isDraft() ? [] : $production->productionPackagings
+            ->map(fn ($row) => ['name' => $row->packagingItem?->name ?? ('#'.$row->packaging_item_id), 'pieces' => (int) $row->quantity_used])
+            ->values()->all();
+        $initialOutputTotals = [];
+        foreach ($production->outputs as $output) {
+            $initialOutputTotals[(int) $output->product_id] = ($initialOutputTotals[(int) $output->product_id] ?? 0) + (int) $output->quantity;
+        }
+
         return view('admin.inventory.productions.edit', [
             'model' => $production,
+            'packagingSnapshot' => $packagingSnapshot,
+            'initialOutputTotals' => $initialOutputTotals,
             ...$this->productCatalogs($production),
             'locations' => Location::query()->where('active', true)->orderBy('name')->get(),
             'defaultLocationId' => $defaultLocationId,
diff --git a/resources/views/admin/inventory/productions/_form_fields.blade.php b/resources/views/admin/inventory/productions/_form_fields.blade.php
index 5e548a8..c5bc930 100644
--- a/resources/views/admin/inventory/productions/_form_fields.blade.php
+++ b/resources/views/admin/inventory/productions/_form_fields.blade.php
@@ -159,6 +159,7 @@
         <table class="table table-sm mb-0">
             <thead><tr><th>{{ __('Artikel') }}</th><th>{{ __('Stück gesamt') }}</th></tr></thead>
             <tbody id="recipe-packaging-preview"></tbody>
+            <tfoot><tr><td colspan="2" class="text-muted small" id="recipe-packaging-hint"></td></tr></tfoot>
         </table>
     </div>
 
@@ -197,7 +198,8 @@
     <div class="col-sm-3">{{ __('Chargen-Nr.') }}</div>
     <div class="col-sm-1"></div>
 </div>
-<div id="production-outputs" data-initial='@json($initialOutputs)' data-packaging-bom='@json(($packagingBom ?? []) === [] ? (object) [] : $packagingBom)'></div>
+<div id="production-outputs" data-initial='@json($initialOutputs)' data-packaging-bom='@json(($packagingBom ?? []) === [] ? (object) [] : $packagingBom)'
+     data-packaging-snapshot='@json($packagingSnapshot ?? [])' data-initial-output-totals='@json(($initialOutputTotals ?? []) === [] ? (object) [] : $initialOutputTotals)'></div>
 <button type="button" class="btn btn-sm btn-outline-secondary mb-3" id="btn-add-output">{{ __('+ weitere Ergebniszeile') }}</button>
 
 <script type="text/template" id="output-row-template">
diff --git a/resources/views/admin/inventory/productions/_scripts.blade.php b/resources/views/admin/inventory/productions/_scripts.blade.php
index ee8c3c3..7d6efa5 100644
--- a/resources/views/admin/inventory/productions/_scripts.blade.php
+++ b/resources/views/admin/inventory/productions/_scripts.blade.php
@@ -366,7 +366,48 @@
         // F-07: Verpackungs-Vorschau aus dem Produktionsergebnis (Outputs × Stückliste),
         // dieselbe Basis wie die Buchung beim Abschluss — nicht aus Planungsprodukt/-menge.
         var packagingBom = $('#production-outputs').data('packaging-bom') || {};
+        // N-04: gespeicherter Snapshot einer gebuchten Produktion + Ergebnissummen beim Öffnen.
+        var packagingSnapshot = $('#production-outputs').data('packaging-snapshot') || [];
+        var initialOutputTotals = $('#production-outputs').data('initial-output-totals') || {};
+
+        function currentOutputTotals() {
+            var totals = {};
+            $('#production-outputs .output-row').each(function () {
+                var pid = String($(this).find('.output-product').val() || '');
+                var qty = parseInt($(this).find('.output-quantity').val(), 10) || 0;
+                if (pid) {
+                    totals[pid] = (totals[pid] || 0) + qty;
+                }
+            });
+            return totals;
+        }
+
+        function sameTotals(a, b) {
+            var keys = Object.keys(a).concat(Object.keys(b));
+            for (var i = 0; i < keys.length; i++) {
+                if ((a[keys[i]] || 0) !== (b[keys[i]] || 0)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
         function renderPackagingPreview() {
+            var $hint = $('#recipe-packaging-hint');
+            if (packagingSnapshot.length > 0 && sameTotals(currentOutputTotals(), initialOutputTotals)) {
+                var $snap = $('#recipe-packaging-preview').empty();
+                packagingSnapshot.forEach(function (pk) {
+                    $snap.append($('<tr></tr>')
+                        .append($('<td></td>').text(pk.name))
+                        .append($('<td></td>').text(pk.pieces)));
+                });
+                $hint.text('{{ __('Gespeicherter Verpackungsverbrauch dieser Produktion — bleibt erhalten, solange Ergebnisprodukte und Stückzahlen unverändert sind.') }}');
+                return;
+            }
+            $hint.text(packagingSnapshot.length > 0
+                ? '{{ __('Ergebnis geändert — Verpackungsverbrauch wird beim Speichern mit der aktuellen Stückliste neu berechnet.') }}'
+                : '');
+
             var totals = {};
             var order = [];
             $('#production-outputs .output-row').each(function () {
diff --git a/tests/Feature/ProductionDraftTest.php b/tests/Feature/ProductionDraftTest.php
index 3a19720..056cd29 100644
--- a/tests/Feature/ProductionDraftTest.php
+++ b/tests/Feature/ProductionDraftTest.php
@@ -3,12 +3,15 @@
 use App\Models\Country;
 use App\Models\Ingredient;
 use App\Models\Location;
+use App\Models\PackagingItem;
+use App\Models\PackagingMaterial;
 use App\Models\Product;
 use App\Models\ProductIngredient;
 use App\Models\Production;
 use App\Models\RecipePhase;
 use App\Models\StockEntry;
 use App\Models\Supplier;
+use App\Repositories\ProductRepository;
 use App\Services\InventoryService;
 use App\Services\ProductionService;
 use App\Services\ProductStockService;
@@ -443,3 +446,124 @@ test('F-18: mehrere zwischenspeichern-buttons und touch-regeln für das notizfel
     $edit = $this->get(route('admin.inventory.productions.edit', $done))->assertOk()->getContent();
     expect(substr_count($edit, 'btn-save-draft'))->toBe(0);
 });
+
+test('N-01: ist-menge ohne gewählte charge bleibt im entwurf erhalten und wird beim wiederöffnen vorbelegt', function () {
+    $user = draftUser();
+    $location = Location::factory()->create();
+    $supplier = Supplier::factory()->create();
+    $ing = draftIngredient();
+    $product = draftRecipeProduct($ing);
+    $stock = draftStock($ing, $location, $supplier, $user);
+
+    Passport::actingAs($user);
+    $this->actingAs($user, 'user');
+    $head = ['product_id' => $product->id, 'location_id' => $location->id, 'produced_at' => '2026-08-01', 'quantity' => 1];
+
+    $this->post(route('admin.inventory.productions.store'), $head + [
+        'save_mode' => 'draft',
+        'ingredient_lines' => [['ingredient_id' => $ing->id, 'batch_key' => '', 'quantity_used' => '9,8']],
+    ])->assertRedirect()->assertSessionHasNoErrors();
+
+    $draft = Production::query()->where('product_id', $product->id)->sole();
+    $line = $draft->productionIngredients()->sole();
+    expect((float) $line->quantity_used)->toBe(9.8)
+        ->and($line->stock_entry_id)->toBeNull()
+        ->and($line->batch_key)->toBeNull();
+
+    $html = $this->get(route('admin.inventory.productions.edit', $draft))->assertOk()->getContent();
+    $start = strpos($html, 'var existingLines = ') + strlen('var existingLines = ');
+    $existing = json_decode(substr($html, $start, strpos($html, ';', $start) - $start), true);
+    expect($existing[$ing->id.'|'][0]['batch_key'])->toBe('')
+        ->and((float) $existing[$ing->id.'|'][0]['quantity_used'])->toBe(9.8);
+
+    // Abschluss ohne Charge scheitert (Charge ist Pflicht), mit Charge klappt es.
+    $this->from(route('admin.inventory.productions.edit', $draft))->put(route('admin.inventory.productions.update', $draft), $head + [
+        'save_mode' => 'complete',
+        'ingredient_lines' => [['ingredient_id' => $ing->id, 'batch_key' => '', 'quantity_used' => '9,8']],
+        'outputs' => [['product_id' => $product->id, 'quantity' => 1, 'batch_number' => null]],
+    ])->assertSessionHasErrors();
+    $this->put(route('admin.inventory.productions.update', $draft), $head + [
+        'save_mode' => 'complete',
+        'ingredient_lines' => [['ingredient_id' => $ing->id, 'batch_key' => $stock->batchGroupKey(), 'quantity_used' => '9,8']],
+        'outputs' => [['product_id' => $product->id, 'quantity' => 1, 'batch_number' => null]],
+    ])->assertSessionHasNoErrors();
+    expect($draft->fresh()->isDraft())->toBeFalse();
+});
+
+test('N-02: unverändertes artikelspeichern erhält die phasenzuordnung der produktionszeilen; doppelter rohstoff je phase wird abgelehnt', function () {
+    $user = draftUser();
+    $location = Location::factory()->create();
+    $supplier = Supplier::factory()->create();
+    $ing = draftIngredient();
+    $stock = draftStock($ing, $location, $supplier, $user);
+
+    $product = Product::query()->create(['name' => 'Draft-N02', 'title' => 'Draft-N02', 'active' => true]);
+    $repo = new ProductRepository($product);
+    $recipe = [
+        'id' => (string) $product->id, 'name' => $product->name, 'title' => $product->title, 'active' => '1',
+        'manufacturer_inci_sync_sent' => '1',
+        'mfg_phase_name' => ['Phase A', 'Phase B'], 'mfg_phase_note' => ['', ''],
+        'mfg_ingredient_id' => [$ing->id, $ing->id], 'mfg_gram' => ['6', '4'], 'mfg_factor' => ['1', '1'], 'mfg_row_phase' => ['0', '1'],
+    ];
+    $repo->update($recipe);
+    $phases = RecipePhase::query()->where('product_id', $product->id)->orderBy('pos')->get();
+    expect($phases)->toHaveCount(2);
+    [$phaseA, $phaseB] = [$phases[0], $phases[1]];
+
+    $draft = app(ProductionService::class)->store(
+        ['product_id' => $product->id, 'location_id' => $location->id, 'produced_at' => '2026-08-01', 'quantity' => 1, 'notes' => null],
+        [
+            ['ingredient_id' => $ing->id, 'stock_entry_id' => $stock->id, 'recipe_phase_id' => $phaseA->id, 'quantity_used' => '6'],
+            ['ingredient_id' => $ing->id, 'stock_entry_id' => $stock->id, 'recipe_phase_id' => $phaseB->id, 'quantity_used' => '4'],
+        ],
+        $user->id, [], true
+    );
+
+    // Artikel unverändert erneut speichern (wie das Produktformular) → Phasen-IDs bleiben.
+    (new ProductRepository($product->fresh()))->update($recipe);
+    $after = RecipePhase::query()->where('product_id', $product->id)->orderBy('pos')->pluck('id')->all();
+    expect($after)->toBe([$phaseA->id, $phaseB->id])
+        ->and($draft->productionIngredients()->where('recipe_phase_id', $phaseA->id)->sum('quantity_used'))->toEqual(6)
+        ->and($draft->productionIngredients()->where('recipe_phase_id', $phaseB->id)->sum('quantity_used'))->toEqual(4);
+
+    // Umbenennen + zusätzliche Phase: bestehende Phasen bleiben, neue kommt dazu.
+    (new ProductRepository($product->fresh()))->update(array_merge($recipe, [
+        'mfg_phase_name' => ['Phase A', 'Phase B neu', 'Phase C'], 'mfg_phase_note' => ['', '', ''],
+        'mfg_ingredient_id' => [$ing->id, $ing->id], 'mfg_row_phase' => ['0', '1'],
+    ]));
+    expect(RecipePhase::query()->where('product_id', $product->id)->count())->toBe(3)
+        ->and($phaseB->fresh()->name)->toBe('Phase B neu')
+        ->and($draft->productionIngredients()->whereNull('recipe_phase_id')->count())->toBe(0);
+
+    // Derselbe Rohstoff zweimal in derselben Phase wird abgelehnt.
+    expect(fn () => (new ProductRepository($product->fresh()))->update(array_merge($recipe, [
+        'mfg_ingredient_id' => [$ing->id, $ing->id], 'mfg_row_phase' => ['0', '0'],
+    ])))->toThrow(ValidationException::class);
+});
+
+test('N-04: bearbeitungsformular einer gebuchten produktion liefert den gespeicherten verpackungs-snapshot und die ergebnissummen', function () {
+    $user = draftUser();
+    $location = Location::factory()->create();
+    $supplier = Supplier::factory()->create();
+    $material = PackagingMaterial::factory()->create();
+    $pk = PackagingItem::factory()->create(['packaging_material_id' => $material->id, 'supplier_id' => $supplier->id, 'name' => 'N04-Tiegel', 'category' => 'packaging']);
+    $product = Product::query()->create(['name' => 'Draft-N04', 'title' => 'Draft-N04', 'active' => true, 'no_recipe_required' => true]);
+    $product->packagings()->sync([$pk->id => ['quantity' => 1, 'pos' => 0]]);
+
+    $done = app(ProductionService::class)->store(
+        ['product_id' => $product->id, 'location_id' => $location->id, 'produced_at' => '2026-08-01', 'quantity' => 1, 'notes' => null],
+        [], $user->id, [['product_id' => $product->id, 'quantity' => 1, 'batch_number' => null]]
+    );
+    $product->packagings()->sync([$pk->id => ['quantity' => 2, 'pos' => 0]]);
+
+    $this->actingAs($user, 'user');
+    $html = $this->get(route('admin.inventory.productions.edit', $done))->assertOk()->getContent();
+    $start = strpos($html, "data-packaging-snapshot='") + strlen("data-packaging-snapshot='");
+    $snapshot = json_decode(substr($html, $start, strpos($html, "'", $start) - $start), true);
+    $start = strpos($html, "data-initial-output-totals='") + strlen("data-initial-output-totals='");
+    $totals = json_decode(substr($html, $start, strpos($html, "'", $start) - $start), true);
+
+    expect($snapshot)->toBe([['name' => 'N04-Tiegel', 'pieces' => 1]])
+        ->and($totals)->toBe([(string) $product->id => 1])
+        ->and($html)->toContain('Gespeicherter Verpackungsverbrauch');
+});