diff --git a/models/workflow_execution/workflow_scheduler.go b/models/workflow_execution/workflow_scheduler.go
index 087086f..16ee325 100644
--- a/models/workflow_execution/workflow_scheduler.go
+++ b/models/workflow_execution/workflow_scheduler.go
@@ -55,7 +55,7 @@ func NewScheduler(start string, end string, durationInS float64, cron string) *W
 }
 
 func (ws *WorkflowSchedule) CheckBooking(wfID string, request *tools.APIRequest) (bool, *workflow.Workflow, []*WorkflowExecution, []*booking.Booking, error) {
-	l := logs.GetLogger().With().Str("SchedulerID",ws.UUID).Logger()
+	l := logs.GetLogger().With().Str("SchedulerID", ws.UUID).Logger()
 	l.Debug().Msg("Checking booking")
 	if request.Caller == nil && request.Caller.URLS == nil && request.Caller.URLS[tools.BOOKING] == nil || request.Caller.URLS[tools.BOOKING][tools.GET] == "" {
 		return false, nil, []*WorkflowExecution{}, []*booking.Booking{}, errors.New("no caller defined")
@@ -88,9 +88,9 @@ func (ws *WorkflowSchedule) CheckBooking(wfID string, request *tools.APIRequest)
 
 	errCh := make(chan error, len(bookings))
 	var m sync.Mutex
-	
+
 	for _, b := range bookings {
-		go getBooking(l, b, request, wf, execs, bookings, errCh, &m)	
+		go getBooking(l, b, request, wf, execs, bookings, errCh, &m)
 	}
 
 	for i := 0; i < len(bookings); i++ {
@@ -103,18 +103,15 @@ func (ws *WorkflowSchedule) CheckBooking(wfID string, request *tools.APIRequest)
 }
 
 func getBooking(l zerolog.Logger, b *booking.Booking, request *tools.APIRequest, wf *workflow.Workflow, execs []*WorkflowExecution, bookings []*booking.Booking, errCh chan error, m *sync.Mutex) {
-	
+
 	m.Lock()
-	// deep copy du caller
-	var c tools.HTTPCaller
-	err := request.Caller.DeepCopy(c)
-	if err != nil{
+	c, err := getCallerCopy(request, errCh)
+	if err != nil {
 		errCh <- err
 		return
 	}
-	c.URLS = request.Caller.URLS
 	m.Unlock()
-	// Delock
+
 	bl := l.With().Str("booking", b.UUID).Logger()
 	meth := request.Caller.URLS[tools.BOOKING][tools.GET]
 	meth = strings.ReplaceAll(meth, ":id", b.ResourceID)
@@ -132,6 +129,17 @@ func getBooking(l zerolog.Logger, b *booking.Booking, request *tools.APIRequest,
 	errCh <- nil
 }
 
+func getCallerCopy(request *tools.APIRequest, errCh chan error) (tools.HTTPCaller, error) {
+	var c tools.HTTPCaller
+	err := request.Caller.DeepCopy(c)
+	if err != nil {
+		errCh <- err
+		return tools.HTTPCaller{}, nil
+	}
+	c.URLS = request.Caller.URLS
+	return c, err
+}
+
 func (ws *WorkflowSchedule) Schedules(wfID string, request *tools.APIRequest) (*WorkflowSchedule, *workflow.Workflow, []*WorkflowExecution, error) {
 	if request == nil {
 		return ws, nil, []*WorkflowExecution{}, errors.New("no request found")
@@ -150,16 +158,20 @@ func (ws *WorkflowSchedule) Schedules(wfID string, request *tools.APIRequest) (*
 		return ws, nil, executions, errors.New("could not book the workflow : " + fmt.Sprintf("%v", err))
 	}
 	ws.Workflow = wf
+
+	var errCh = make(chan error, len(bookings))
+	var m sync.Mutex
+
 	for _, booking := range bookings {
-		l := logs.GetLogger().With().Str("SchedulerID",ws.UUID).Logger()
-		l.Debug().Msg("Booking " + booking.UUID + " on " + booking.DestPeerID)
-		_, err := (&peer.Peer{}).LaunchPeerExecution(booking.DestPeerID, "",
-			tools.BOOKING, tools.POST, booking.Serialize(booking), request.Caller)
-		l.Debug().Msg("Received answer for booking " + booking.UUID + " on " + booking.DestPeerID)
-		if err != nil {
-			return ws, wf, executions, errors.New("could not launch the peer execution : " + fmt.Sprintf("%v", err))
+		go ws.BookExecs(booking, request, errCh, &m)
+		
+		for i := 0; i < len(bookings); i++ {
+			if err := <- errCh ; err != nil {
+				return ws, wf, executions, errors.New("could not launch the peer execution : " + fmt.Sprintf("%v", err))
+			}
 		}
 	}
+
 	fmt.Println("Schedules")
 	for _, exec := range executions {
 		err := exec.PurgeDraft(request)
@@ -173,6 +185,30 @@ func (ws *WorkflowSchedule) Schedules(wfID string, request *tools.APIRequest) (*
 	return ws, wf, executions, nil
 }
 
+func (ws *WorkflowSchedule) BookExecs(booking *booking.Booking, request *tools.APIRequest, errCh chan error, m *sync.Mutex) {
+
+	m.Lock()
+	c, err := getCallerCopy(request, errCh)
+	if err != nil {
+		errCh <- err
+		return
+	}
+	m.Unlock()
+
+	l := logs.GetLogger().With().Str("SchedulerID", ws.UUID).Logger()
+	l.Debug().Msg("Booking " + booking.UUID + " on " + booking.DestPeerID)
+	_, err = (&peer.Peer{}).LaunchPeerExecution(booking.DestPeerID, "",
+		tools.BOOKING, tools.POST, booking.Serialize(booking), &c)
+	l.Debug().Msg("Received answer for booking " + booking.UUID + " on " + booking.DestPeerID)
+	
+	if err != nil {
+		errCh <- err
+		return
+	}
+
+	errCh <- nil
+}
+
 /*
 BOOKING IMPLIED TIME, not of subscription but of execution
 so is processing time execution time applied on computes