公司場景 Pattern

Pattern 1: 告警規則引擎

場景：不同設備、不同客戶的告警條件不同。現場工程師需要自行調整閾值（溫度 > X 且壓力 < Y 觸發告警），不需要工程師改程式碼重新部署。

規則定義（存在 DB，UI 可編輯）

[{
  "WorkflowName": "AlarmRules_CMP01",
  "Rules": [
    {
      "RuleName": "OverTemperature",
      "Expression": "Temperature > 80",
      "SuccessEvent": "Critical",
      "ErrorMessage": "溫度 $(Temperature)°C 超過上限 80°C",
      "Properties": { "Category": "Temperature", "Priority": 1 }
    },
    {
      "RuleName": "HighPressure",
      "Expression": "Pressure > 150 OR Pressure < 30",
      "SuccessEvent": "Warning",
      "ErrorMessage": "壓力 $(Pressure) kPa 超出安全範圍 (30-150)",
      "Properties": { "Category": "Pressure", "Priority": 2 }
    },
    {
      "RuleName": "CommunicationDegraded",
      "Expression": "SuccessRate < 0.95 AND SampleCount > 100",
      "SuccessEvent": "Warning",
      "ErrorMessage": "通訊成功率 $(SuccessRate) 低於 95%",
      "Properties": { "Category": "Communication", "Priority": 3 }
    },
    {
      "RuleName": "PumpDryRun",
      "LocalParams": [
        { "Name": "isPumpRunning", "Expression": "PumpStatus == 1" },
        { "Name": "noFlow", "Expression": "FlowRate < 0.5" }
      ],
      "Expression": "isPumpRunning AND noFlow",
      "SuccessEvent": "Critical",
      "ErrorMessage": "泵浦乾轉：運轉中但流量不足"
    }
  ]
}]

告警服務實作

public class DynamicAlarmService
{
    private readonly RulesEngine.RulesEngine _rulesEngine;
    private readonly IAlarmRepository _alarmRepository;
    private readonly ILogger<DynamicAlarmService> _logger;

    public DynamicAlarmService(
        IRuleRepository ruleRepository,
        IAlarmRepository alarmRepository,
        ILogger<DynamicAlarmService> logger)
    {
        _alarmRepository = alarmRepository;
        _logger = logger;

        // 從 DB 載入規則
        var workflows = ruleRepository.GetAllWorkflows();
        _rulesEngine = new RulesEngine.RulesEngine(workflows.ToArray());
    }

    public async Task EvaluateAsync(string deviceId, SensorSnapshot snapshot)
    {
        var workflowName = $"AlarmRules_{deviceId}";
        var results = await _rulesEngine.ExecuteAllRulesAsync(workflowName, snapshot);

        foreach (var result in results.Where(r => r.IsSuccess))
        {
            var severity = Enum.Parse<AlarmSeverity>(result.Rule.SuccessEvent);
            var category = result.Rule.Properties["Category"]?.ToString();

            _logger.LogWarning(
                "Alarm triggered: {RuleName} on {DeviceId} — {Severity}",
                result.Rule.RuleName, deviceId, severity);

            await _alarmRepository.RaiseAsync(new Alarm
            {
                DeviceId = deviceId,
                RuleName = result.Rule.RuleName,
                Severity = severity,
                Category = category,
                Message = result.Rule.ErrorMessage
            });
        }
    }

    /// <summary>
    /// 規則變更時（UI 編輯後），重新載入
    /// </summary>
    public void ReloadRules(Workflow[] workflows)
    {
        _rulesEngine.ClearWorkflows();
        _rulesEngine.AddOrUpdateWorkflow(workflows);
        _logger.LogInformation("Alarm rules reloaded: {Count} workflows", workflows.Length);
    }
}

---

Pattern 2: MES 整合判斷

場景：不同客戶的 MES 系統有不同的資料格式和判斷邏輯。用 RulesEngine 讓每個客戶的整合邏輯可配置，不需要為每家 MES 寫一套程式碼。

[{
  "WorkflowName": "MES_Validation_Walton",
  "Rules": [
    {
      "RuleName": "ValidateLotId",
      "Expression": "LotId != null AND LotId.Length == 12 AND LotId.StartsWith(\"WLT\")",
      "ErrorMessage": "Walton Lot ID 必須為 12 碼且以 WLT 開頭"
    },
    {
      "RuleName": "ValidateRecipeMatch",
      "Expression": "MesRecipeId == EquipmentRecipeId",
      "ErrorMessage": "MES Recipe $(MesRecipeId) 與設備 Recipe $(EquipmentRecipeId) 不匹配"
    },
    {
      "RuleName": "ValidateOperator",
      "Expression": "OperatorId != null AND IsOperatorCertified == true",
      "ErrorMessage": "操作員 $(OperatorId) 未通過認證"
    }
  ]
},
{
  "WorkflowName": "MES_Validation_Jope",
  "Rules": [
    {
      "RuleName": "ValidateLotId",
      "Expression": "LotId != null AND LotId.Length >= 8",
      "ErrorMessage": "Jope Lot ID 至少 8 碼"
    },
    {
      "RuleName": "CheckMaintenanceWindow",
      "Expression": "IsInMaintenanceWindow == false",
      "ErrorMessage": "設備在維護時段，不允許投產"
    }
  ]
}]

public class MesIntegrationService
{
    private readonly RulesEngine.RulesEngine _rulesEngine;

    public async Task<ValidationResult> ValidateLotStartAsync(
        string customerId, LotStartRequest request)
    {
        var workflowName = $"MES_Validation_{customerId}";
        var results = await _rulesEngine.ExecuteAllRulesAsync(workflowName, request);

        var failures = results
            .Where(r => !r.IsSuccess)
            .Select(r => r.Rule.ErrorMessage)
            .ToList();

        return new ValidationResult
        {
            IsValid = failures.Count == 0,
            Errors = failures
        };
    }
}

---

Pattern 3: Recipe 進階條件（未來擴充）

場景：目前 EndConditionType 提供三種固定類型（時間、計數、條件）。如果未來需要支援任意複合條件，可以用 RulesEngine 表達式：

{
  "WorkflowName": "RecipeEndCondition",
  "Rules": [{
    "RuleName": "ComplexEndCondition",
    "Expression": "Concentration >= TargetConcentration AND pH >= 6.5 AND pH <= 7.5 AND ElapsedMinutes >= MinProcessTime",
    "SuccessEvent": "EndProcess"
  }]
}

public class RecipeStepExecutor
{
    private readonly RulesEngine.RulesEngine _rulesEngine;

    public async Task<bool> ShouldEndStepAsync(RecipeStep step, ProcessState state)
    {
        // 固定條件用原本的 enum
        if (step.EndConditionType != EndConditionType.Expression)
        {
            return EvaluateFixedCondition(step, state);
        }

        // 動態表達式用 RulesEngine
        var input = new
        {
            state.Concentration,
            step.TargetConcentration,
            state.pH,
            ElapsedMinutes = state.Elapsed.TotalMinutes,
            step.MinProcessTime
        };

        var results = await _rulesEngine.ExecuteAllRulesAsync(
            "RecipeEndCondition", input);

        return results.Any(r => r.IsSuccess && r.Rule.SuccessEvent == "EndProcess");
    }
}

何時引入

這是未來擴充的方向。目前三種 EndConditionType 夠用時，不需要提前引入 RulesEngine 增加複雜度。等到確實有客戶需求要求更靈活的結束條件時再啟用。

---

Pattern 4: 資料品質檢查

場景：感測器數據在寫入資料庫前需要驗證合理性。規則隨設備校正狀態調整。

[{
  "WorkflowName": "DataQuality_TemperatureSensor",
  "Rules": [
    {
      "RuleName": "PhysicalRange",
      "Expression": "Value >= -50 AND Value <= 500",
      "ErrorMessage": "溫度 $(Value)°C 超出物理量程 (-50 ~ 500)"
    },
    {
      "RuleName": "RateOfChange",
      "Expression": "Math.Abs(Value - PreviousValue) < 50",
      "ErrorMessage": "溫度變化率異常：$(Value) → $(PreviousValue)，差值超過 50°C"
    },
    {
      "RuleName": "SensorOnline",
      "Expression": "TimeSinceLastUpdate.TotalSeconds < 30",
      "ErrorMessage": "感測器超過 30 秒無更新"
    }
  ]
}]

public class DataQualityService
{
    private readonly RulesEngine.RulesEngine _rulesEngine;
    private readonly ILogger<DataQualityService> _logger;

    public async Task<bool> ValidateReadingAsync(
        string sensorType, SensorReading reading, SensorReading? previous)
    {
        var input = new
        {
            reading.Value,
            PreviousValue = previous?.Value ?? reading.Value,
            TimeSinceLastUpdate = DateTime.UtcNow - (previous?.Timestamp ?? DateTime.UtcNow)
        };

        var workflowName = $"DataQuality_{sensorType}";
        var results = await _rulesEngine.ExecuteAllRulesAsync(workflowName, input);

        var failures = results.Where(r => !r.IsSuccess).ToList();
        if (failures.Any())
        {
            _logger.LogWarning(
                "Data quality check failed for {SensorType}: {Failures}",
                sensorType,
                string.Join("; ", failures.Select(f => f.Rule.ErrorMessage)));
            return false;
        }

        return true;
    }
}

---

DI 整合

public static class RulesEngineServiceExtensions
{
    public static IServiceCollection AddRulesEngine(
        this IServiceCollection services,
        IConfiguration configuration)
    {
        services.AddSingleton(sp =>
        {
            var ruleRepo = sp.GetRequiredService<IRuleRepository>();
            var workflows = ruleRepo.GetAllWorkflows();

            var settings = new ReSettings
            {
                EnableExceptionAsErrorMessage = true,
                CustomActions = new Dictionary<string, Func<ActionBase>>
                {
                    { "RaiseAlarm", () => sp.GetRequiredService<RaiseAlarmAction>() }
                }
            };

            return new RulesEngine.RulesEngine(workflows.ToArray(), settings);
        });

        services.AddTransient<RaiseAlarmAction>();
        services.AddTransient<DynamicAlarmService>();
        services.AddTransient<DataQualityService>();

        return services;
    }
}

---

規則版本控制與審計（FDA Part 11）

對於合規場景，規則的變更需要完整的審計軌跡：

public class AuditableRuleRepository : IRuleRepository
{
    private readonly IDbContext _db;
    private readonly ILogger<AuditableRuleRepository> _logger;

    public async Task UpdateRuleAsync(
        string workflowName,
        string ruleName,
        string newExpression,
        string modifiedBy)
    {
        var existing = await _db.Rules
            .FirstAsync(r => r.WorkflowName == workflowName && r.RuleName == ruleName);

        // 記錄變更歷史
        await _db.RuleAuditLogs.AddAsync(new RuleAuditLog
        {
            WorkflowName = workflowName,
            RuleName = ruleName,
            OldExpression = existing.Expression,
            NewExpression = newExpression,
            ModifiedBy = modifiedBy,
            ModifiedAt = DateTime.UtcNow,
            Reason = $"Rule updated by {modifiedBy}"
        });

        existing.Expression = newExpression;
        existing.Version++;
        await _db.SaveChangesAsync();

        _logger.LogWarning(
            "Rule {RuleName} in {WorkflowName} modified by {ModifiedBy}: {OldExpr} → {NewExpr}",
            ruleName, workflowName, modifiedBy,
            existing.Expression, newExpression);
    }
}

---

延伸閱讀

• 概觀 — RulesEngine 基礎概念、適用場景判斷
• FluentValidation 驗證 — 編譯期靜態驗證規則
• Serilog 結構化日誌 — 規則評估結果的結構化記錄