diff --git a/tests/grpc/grpc_test.go b/tests/grpc/grpc_test.go
index adbb3cd..2c8bc77 100644
--- a/tests/grpc/grpc_test.go
+++ b/tests/grpc/grpc_test.go
@@ -5,7 +5,6 @@ import (
 	"errors"
 	"fmt"
 	"log"
-	"math/rand"
 	"net"
 	"os"
 	"testing"
@@ -253,7 +252,7 @@ func Test_Grpc_ReuseInstanceIDSkip(t *testing.T) {
 	cancelListener := startGrpcListener(t, r)
 	defer cancelListener()
 	instanceIDs := api.InstanceID("SKIP_IF_RUNNING_OR_COMPLETED")
-	ReuseIdOption := api.OrchestrationIDReuseOption{
+	reuseIdOption := api.OrchestrationIDReuseOption{
 		CreateOrchestrationAction: protos.CreateOrchestrationAction_SKIP,
 		OrchestrationStatuses: []protos.OrchestrationStatus{
 			protos.OrchestrationStatus_ORCHESTRATION_STATUS_RUNNING,
@@ -264,19 +263,21 @@ func Test_Grpc_ReuseInstanceIDSkip(t *testing.T) {
 
 	id, err := grpcClient.ScheduleNewOrchestration(ctx, "SingleActivity", api.WithInput("世界"), api.WithInstanceID(instanceIDs))
 	require.NoError(t, err)
-	// random sleep a time from 0 to 5 seconds, to allow previous orchestration instance to set in different status
-	randomeDuration := time.Duration(rand.Intn(6)) * time.Second
-	time.Sleep(randomeDuration)
-	// schedule again
-	id, err = grpcClient.ScheduleNewOrchestration(ctx, "SingleActivity", api.WithInput("世界"), api.WithInstanceID(id), api.WithOrchestrationReuseOption(ReuseIdOption))
+	// wait orchestration to start
+	grpcClient.WaitForOrchestrationStart(ctx, id)
+	pivotTime := time.Now()
+	// schedule again, it should skip creating the new orchestration
+	id, err = grpcClient.ScheduleNewOrchestration(ctx, "SingleActivity", api.WithInput("World"), api.WithInstanceID(id), api.WithOrchestrationReuseOption(reuseIdOption))
 	require.NoError(t, err)
 	timeoutCtx, cancelTimeout := context.WithTimeout(ctx, 30*time.Second)
 	defer cancelTimeout()
 	metadata, err := grpcClient.WaitForOrchestrationCompletion(timeoutCtx, id, api.WithFetchPayloads(true))
 	require.NoError(t, err)
 	assert.Equal(t, true, metadata.IsComplete())
+	// the first orchestration should complete as the second one is skipped 
 	assert.Equal(t, `"Hello, 世界!"`, metadata.SerializedOutput)
-	time.Sleep(1 * time.Second)
+	// assert the orchestration created timestamp
+	assert.True(t, pivotTime.After(metadata.CreatedAt))
 }
 
 func Test_Grpc_ReuseInstanceIDTerminate(t *testing.T) {
@@ -303,7 +304,7 @@ func Test_Grpc_ReuseInstanceIDTerminate(t *testing.T) {
 	cancelListener := startGrpcListener(t, r)
 	defer cancelListener()
 	instanceIDs := api.InstanceID("TERMINATE_IF_RUNNING_OR_COMPLETED")
-	ReuseIdOption := api.OrchestrationIDReuseOption{
+	reuseIdOption := api.OrchestrationIDReuseOption{
 		CreateOrchestrationAction: protos.CreateOrchestrationAction_TERMINATE,
 		OrchestrationStatuses: []protos.OrchestrationStatus{
 			protos.OrchestrationStatus_ORCHESTRATION_STATUS_RUNNING,
@@ -314,19 +315,21 @@ func Test_Grpc_ReuseInstanceIDTerminate(t *testing.T) {
 
 	id, err := grpcClient.ScheduleNewOrchestration(ctx, "SingleActivity", api.WithInput("世界"), api.WithInstanceID(instanceIDs))
 	require.NoError(t, err)
-	// random sleep a time from 0 to 5 seconds, to allow previous orchestration instance to set in different status
-	randomeDuration := time.Duration(rand.Intn(6)) * time.Second
-	time.Sleep(randomeDuration)
-	// schedule again
-	id, err = grpcClient.ScheduleNewOrchestration(ctx, "SingleActivity", api.WithInput("世界"), api.WithInstanceID(id), api.WithOrchestrationReuseOption(ReuseIdOption))
+	// wait orchestration to start
+	grpcClient.WaitForOrchestrationStart(ctx, id)
+	pivotTime := time.Now()
+	// schedule again, it should terminate the first orchestration and start a new one
+	id, err = grpcClient.ScheduleNewOrchestration(ctx, "SingleActivity", api.WithInput("World"), api.WithInstanceID(id), api.WithOrchestrationReuseOption(reuseIdOption))
 	require.NoError(t, err)
 	timeoutCtx, cancelTimeout := context.WithTimeout(ctx, 30*time.Second)
 	defer cancelTimeout()
 	metadata, err := grpcClient.WaitForOrchestrationCompletion(timeoutCtx, id, api.WithFetchPayloads(true))
 	require.NoError(t, err)
 	assert.Equal(t, true, metadata.IsComplete())
-	assert.Equal(t, `"Hello, 世界!"`, metadata.SerializedOutput)
-	time.Sleep(1 * time.Second)
+	// the second orchestration should complete.
+	assert.Equal(t, `"Hello, World!"`, metadata.SerializedOutput)
+	// assert the orchestration created timestamp
+	assert.True(t, pivotTime.Before(metadata.CreatedAt))
 }
 
 func Test_Grpc_ReuseInstanceIDThrow(t *testing.T) {
@@ -360,5 +363,4 @@ func Test_Grpc_ReuseInstanceIDThrow(t *testing.T) {
 	if assert.Error(t, err) {
 		assert.Contains(t, err.Error(), "orchestration instance already exists")
 	}
-	time.Sleep(1 * time.Second)
 }