diff --git a/ZoneManager.py b/ZoneManager.py
index 84a0b0a..2ef1d91 100644
--- a/ZoneManager.py
+++ b/ZoneManager.py
@@ -12,8 +12,8 @@ class ZoneManager:
         self.zones = fileIO.loadZones()
         for zone in self.zones:
             zone.setZoneManager(self)
-        self.pipeLine = [] #todo Thread Synchron
-        #self.lock = threading.Lock()
+        self.pipeLine = []
+        self.piplineMutexLock = threading.Lock()
 
     def getZone(self, number):
         for zone in self.zones:
@@ -21,22 +21,23 @@ class ZoneManager:
                 return zone
 
     def addIrrigationJob(self, job):
-        #with self.lock:
+        with self.piplineMutexLock:
             self.pipeLine.append(job)
 
     def deleteIrrigationJobByID(self, id):
-        #with self.lock:
-            i = 0
+        i = 0
+        with self.piplineMutexLock:
             while i < (len(self.pipeLine)):
                 irrigationJob = self.pipeLine[i]
                 if(irrigationJob.id == id):
                     self.pipeLine.pop(i)
+                    break
                 else:
                     i = i + 1
 
     def deleteIrrigationJobsForZone(self, zone):
-        #with self.lock:
-            i = 0
+        i = 0
+        with self.piplineMutexLock:
             while i < (len(self.pipeLine)):
                 irrigationJob = self.pipeLine[i]
                 if (irrigationJob.zone == zone):
@@ -62,10 +63,10 @@ class ZoneManager:
 
     def getPlanedDurationForZone(self, zone):
         totalDuration = 0
-        #with self.lock:
-        for irrigationJob in self.pipeLine:
-            if(irrigationJob.zone == zone):
-                totalDuration = totalDuration + irrigationJob.duration
+        with self.piplineMutexLock:
+            for irrigationJob in self.pipeLine:
+                if(irrigationJob.zone == zone):
+                    totalDuration = totalDuration + irrigationJob.duration
         return totalDuration
 
     def refreshStates(self):
@@ -73,16 +74,21 @@ class ZoneManager:
             zone.refreshState()
 
     def processPipeline(self):
-        #with self.lock:
-            if(len(self.pipeLine) > 0 and (not self.isAnyZoneBusy())):
-                irrigationJob = self.pipeLine[0]
-                irrigationJob.process()
-                self.pipeLine.pop(0)
+        self.piplineMutexLock.acquire()
+        if(len(self.pipeLine) > 0 and (not self.isAnyZoneBusy())):
+            irrigationJob = self.pipeLine[0]
+            self.pipeLine.pop(0)
+            self.piplineMutexLock.release()
+            irrigationJob.process()
+        else:
+            self.piplineMutexLock.release()
+
+
 
     def cronJobs(self):
         self.refreshStates()
         self.processPipeline()
-        print("Executed Cron Jobs of ZoneManager.\nactual Time: " + str(time()))
+        print("Executed Cron Jobs of ZoneManager.")
 
 
 
diff --git a/main.py b/main.py
index 419c506..8645ade 100644
--- a/main.py
+++ b/main.py
@@ -13,8 +13,9 @@ webserver = Webserver(zoneManager=zoneManager, port=80)
 
 def cronJobs():
     while True:
-        time.sleep(0.5)
         zoneManager.cronJobs()
+        print("Cronjobs done\nactual Time: " + str(time.time()))
+        time.sleep(0.5)
 
 if __name__ == "__main__":
     cronjob_Thread = threading.Thread(target=cronJobs)