diff --git a/leak_test_project/Services/LotEngravingService.cs b/leak_test_project/Services/LotEngravingService.cs
deleted file mode 100644
index 2590ae9..0000000
--- a/leak_test_project/Services/LotEngravingService.cs
+++ /dev/null
@@ -1,104 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Text.Json;
-
-namespace leak_test_project.Services
-{
-    /// <summary>
-    /// 로트번호(Lot No)별 각인 순번을 저장하고 관리하는 서비스.
-    /// DB COUNT(*) 의존성을 제거하고, Lot No별로 검사할 때마다 무조건 +1씩 증가하며,
-    /// Lot No 변경 시 1부터 시작하고, 기존 Lot No로 복귀 시 이전 진행 번호부터 이어받아 증가합니다.
-    /// </summary>
-    public class LotEngravingService
-    {
-        private static readonly object _fileLock = new object();
-        private static LotEngravingService _instance;
-        public static LotEngravingService Instance => _instance ??= new LotEngravingService();
-
-        private readonly string _filePath;
-        private readonly Dictionary<string, int> _sequences = new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase);
-
-        public LotEngravingService()
-        {
-            string appDir = AppDomain.CurrentDomain.BaseDirectory;
-            _filePath = Path.Combine(appDir, "lot_sequences.json");
-            LoadSequences();
-        }
-
-        private void LoadSequences()
-        {
-            lock (_fileLock)
-            {
-                try
-                {
-                    if (File.Exists(_filePath))
-                    {
-                        string json = File.ReadAllText(_filePath);
-                        var data = JsonSerializer.Deserialize<Dictionary<string, int>>(json);
-                        if (data != null)
-                        {
-                            _sequences.Clear();
-                            foreach (var kvp in data)
-                            {
-                                _sequences[kvp.Key] = kvp.Value;
-                            }
-                        }
-                    }
-                }
-                catch (Exception ex)
-                {
-                    System.Diagnostics.Debug.WriteLine($"[LotEngravingService] LoadSequences Error: {ex.Message}");
-                }
-            }
-        }
-
-        private void SaveSequences()
-        {
-            lock (_fileLock)
-            {
-                try
-                {
-                    string json = JsonSerializer.Serialize(_sequences, new JsonSerializerOptions { WriteIndented = true });
-                    File.WriteAllText(_filePath, json);
-                }
-                catch (Exception ex)
-                {
-                    System.Diagnostics.Debug.WriteLine($"[LotEngravingService] SaveSequences Error: {ex.Message}");
-                }
-            }
-        }
-
-        /// <summary>
-        /// 지정한 Lot No의 현재 마지막 각인 순번을 조회합니다. (없을 경우 0)
-        /// </summary>
-        public int GetLastSequence(string lotNo)
-        {
-            if (string.IsNullOrWhiteSpace(lotNo)) return 0;
-            string key = lotNo.Trim();
-
-            lock (_fileLock)
-            {
-                return _sequences.TryGetValue(key, out int seq) ? seq : 0;
-            }
-        }
-
-        /// <summary>
-        /// 지정한 Lot No의 다음 각인 순번을 가져오고, 카운터를 +1 증가시켜 영구 저장합니다.
-        /// </summary>
-        public int GetNextSequence(string lotNo)
-        {
-            if (string.IsNullOrWhiteSpace(lotNo)) lotNo = "DEFAULT";
-            string key = lotNo.Trim();
-
-            lock (_fileLock)
-            {
-                int current = _sequences.TryGetValue(key, out int seq) ? seq : 0;
-                int next = current + 1;
-                _sequences[key] = next;
-                SaveSequences();
-                return next;
-            }
-        }
-    }
-}