diff --git a/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGOperations.java b/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGOperations.java
index da62e4092..e20612913 100644
--- a/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGOperations.java
+++ b/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGOperations.java
@@ -51,7 +51,7 @@
 import java.util.function.Supplier;
 
 @Slf4j
-public class DAGOperations {
+public class DAGOperations implements DAGOperationsInterface {
     private static final String EXECUTION_ID = "executionId";
 
     private final ExecutorService runnerExecutor;
diff --git a/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGOperationsInterface.java b/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGOperationsInterface.java
new file mode 100644
index 000000000..e4ea2c464
--- /dev/null
+++ b/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGOperationsInterface.java
@@ -0,0 +1,18 @@
+package com.weibo.rill.flow.olympicene.traversal;
+
+import com.weibo.rill.flow.interfaces.model.task.TaskInfo;
+import com.weibo.rill.flow.olympicene.core.model.NotifyInfo;
+import com.weibo.rill.flow.olympicene.core.model.dag.DAGInfo;
+import com.weibo.rill.flow.olympicene.core.model.dag.DAGInvokeMsg;
+import com.weibo.rill.flow.olympicene.core.model.dag.DAGStatus;
+import org.apache.commons.lang3.tuple.Pair;
+
+import java.util.Collection;
+import java.util.Map;
+
+public interface DAGOperationsInterface {
+    void finishDAG(String executionId, DAGInfo dagInfo, DAGStatus dagStatus, DAGInvokeMsg dagInvokeMsg);
+    void finishTaskAsync(String executionId, String taskCategory, NotifyInfo notifyInfo, Map<String, Object> output);
+    void finishTaskSync(String executionId, String taskCategory, NotifyInfo notifyInfo, Map<String, Object> output);
+    void runTasks(String executionId, Collection<Pair<TaskInfo, Map<String, Object>>> taskInfoToContexts);
+}
diff --git a/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGTraversal.java b/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGTraversal.java
index 73b16e4db..c350133e8 100644
--- a/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGTraversal.java
+++ b/rill-flow-dag/olympicene-traversal/src/main/java/com/weibo/rill/flow/olympicene/traversal/DAGTraversal.java
@@ -56,7 +56,7 @@ public class DAGTraversal {
     private final DAGStorageProcedure dagStorageProcedure;
     private final ExecutorService traversalExecutor;
     @Setter
-    private DAGOperations dagOperations;
+    private DAGOperationsInterface dagOperations;
     @Setter
     private Stasher stasher;