diff --git a/examples/python/scheduling_with_transitions_sat.py b/examples/python/scheduling_with_transitions_sat.py
index 6c91f31d8b..29fdef10b0 100644
--- a/examples/python/scheduling_with_transitions_sat.py
+++ b/examples/python/scheduling_with_transitions_sat.py
@@ -33,11 +33,56 @@ def main():
   """Solves the scheduling with transitions problem."""
 
   #----------------------------------------------------------------------------
-  jobs = [[[(100, 0, 'R6'), (2, 1, 'R6')]], [[(2, 0, 'R3'), (100, 1, 'R3')]],
-          [[(100, 0, 'R1'), (16, 1, 'R1')]], [[(1, 0, 'R1'), (38, 1, 'R1')]],
-          [[(14, 0, 'R1'), (10, 1, 'R1')]], [[(16, 0, 'R3'), (17, 1, 'R3')]],
-          [[(14, 0, 'R3'), (14, 1, 'R3')]], [[(14, 0, 'R3'), (15, 1, 'R3')]],
-          [[(14, 0, 'R3'), (13, 1, 'R3')]], [[(100, 0, 'R1'), (38, 1, 'R1')]]]
+  small_jobs = [[[(100, 0, 'R6'), (2, 1, 'R6')]],
+                [[(2, 0, 'R3'), (100, 1, 'R3')]],
+                [[(100, 0, 'R1'), (16, 1, 'R1')]],
+                [[(1, 0, 'R1'), (38, 1, 'R1')]],
+                [[(14, 0, 'R1'), (10, 1, 'R1')]],
+                [[(16, 0, 'R3'), (17, 1, 'R3')]],
+                [[(14, 0, 'R3'), (14, 1, 'R3')]],
+                [[(14, 0, 'R3'), (15, 1, 'R3')]],
+                [[(14, 0, 'R3'), (13, 1, 'R3')]],
+                [[(100, 0, 'R1'), (38, 1, 'R1')]]]
+
+  large_jobs = [
+      [[(-1, 0, 'R1'), (10, 1, 'R1')]], [[(9, 0, 'R3'),  (22, 1, 'R3')]],
+      [[(-1, 0, 'R3'), (13, 1, 'R3')]], [[(-1, 0, 'R3'), (38, 1, 'R3')]],
+      [[(-1, 0, 'R3'), (38, 1, 'R3')]], [[(-1, 0, 'R3'), (16, 1, 'R3')]],
+      [[(-1, 0, 'R3'), (11, 1, 'R3')]], [[(-1, 0, 'R3'), (13, 1, 'R3')]],
+      [[(13, 0, 'R3'), (-1, 1, 'R3')]], [[(13, 0, 'R3'), (-1, 1, 'R3')]],
+      [[(-1, 0, 'R3'), (15, 1, 'R3')]], [[(12, 0, 'R1'), (-1, 1, 'R1')]],
+      [[(14, 0, 'R1'), (-1, 1, 'R1')]], [[(13, 0, 'R3'), (-1, 1, 'R3')]],
+      [[(-1, 0, 'R3'), (15, 1, 'R3')]], [[(14, 0, 'R1'), (-1, 1, 'R1')]],
+      [[(13, 0, 'R3'), (-1, 1, 'R3')]], [[(14, 0, 'R3'), (-1, 1, 'R3')]],
+      [[(13, 0, 'R1'), (-1, 1, 'R1')]], [[(15, 0, 'R1'), (-1, 1, 'R1')]],
+      [[(-1, 0, 'R2'), (16, 1, 'R2')]], [[(-1, 0, 'R2'), (16, 1, 'R2')]],
+      [[(-1, 0, 'R5'), (27, 1, 'R5')]], [[(-1, 0, 'R5'), (13, 1, 'R5')]],
+      [[(-1, 0, 'R5'), (13, 1, 'R5')]], [[(-1, 0, 'R5'), (13, 1, 'R5')]],
+      [[(13, 0, 'R1'), (-1, 1, 'R1')]], [[(-1, 0, 'R1'), (17, 1, 'R1')]],
+      [[(14, 0, 'R4'), (-1, 1, 'R4')]], [[(13, 0, 'R1'), (-1, 1, 'R1')]],
+      [[(16, 0, 'R4'), (-1, 1, 'R4')]], [[(16, 0, 'R4'), (-1, 1, 'R4')]],
+      [[(16, 0, 'R4'), (-1, 1, 'R4')]], [[(16, 0, 'R4'), (-1, 1, 'R4')]],
+      [[(13, 0, 'R1'), (-1, 1, 'R1')]], [[(13, 0, 'R1'), (-1, 1, 'R1')]],
+      [[(14, 0, 'R4'), (-1, 1, 'R4')]], [[(13, 0, 'R1'), (-1, 1, 'R1')]],
+      [[(12, 0, 'R1'), (-1, 1, 'R1')]], [[(14, 0, 'R4'), (-1, 1, 'R4')]],
+      [[(-1, 0, 'R5'), (14, 1, 'R5')]], [[(14, 0, 'R4'), (-1, 1, 'R4')]],
+      [[(14, 0, 'R4'), (-1, 1, 'R4')]], [[(14, 0, 'R4'), (-1, 1, 'R4')]],
+      [[(14, 0, 'R4'), (-1, 1, 'R4')]], [[(-1, 0, 'R1'), (21, 1, 'R1')]],
+      [[(-1, 0, 'R1'), (21, 1, 'R1')]], [[(-1, 0, 'R1'), (21, 1, 'R1')]],
+      [[(13, 0, 'R6'), (-1, 1, 'R6')]], [[(13, 0, 'R2'), (-1, 1, 'R2')]],
+      [[(-1, 0, 'R6'), (12, 1, 'R6')]], [[(13, 0, 'R1'), (-1, 1, 'R1')]],
+      [[(13, 0, 'R1'), (-1, 1, 'R1')]], [[(-1, 0, 'R6'), (14, 1, 'R6')]],
+      [[(-1, 0, 'R5'), (5, 1, 'R5')]], [[(3, 0, 'R2'), (-1, 1, 'R2')]],
+      [[(-1, 0, 'R1'), (21, 1, 'R1')]], [[(-1, 0, 'R1'), (21, 1, 'R1')]],
+      [[(-1, 0, 'R1'), (21, 1, 'R1')]], [[(-1, 0, 'R5'), (1, 1, 'R5')]],
+      [[(1, 0, 'R2'), (-1, 1, 'R2')]], [[(-1, 0, 'R2'), (19, 1, 'R2')]],
+      [[(13, 0, 'R4'), (-1, 1, 'R4')]], [[(12, 0, 'R4'), (-1, 1, 'R4')]],
+      [[(-1, 0, 'R3'), (2, 1, 'R3')]], [[(11, 0, 'R4'), (-1, 1, 'R4')]],
+      [[(6, 0, 'R6'), (-1, 1, 'R6')]], [[(6, 0, 'R6'), (-1, 1, 'R6')]],
+      [[(1, 0, 'R2'), (-1, 1, 'R2')]], [[(12, 0, 'R4'), (-1, 1, 'R4')]]
+  ]
+
+  jobs = large_jobs
 
   #----------------------------------------------------------------------------
   # Helper data.
@@ -51,7 +96,7 @@ def main():
   model = cp_model.CpModel()
 
   #----------------------------------------------------------------------------
-  # Sum each lot longest process time for max makespan.
+  # Compute a maximum makespan greedily.
   horizon = 0
   for job in jobs:
     for task in job:
@@ -63,7 +108,7 @@ def main():
   print('Horizon = %i' % horizon)
 
   #----------------------------------------------------------------------------
-  # Scan the jobs and create the relevant variables and intervals.
+  # Global storage of variables.
   intervals_per_machines = collections.defaultdict(list)
   presences_per_machines = collections.defaultdict(list)
   starts_per_machines = collections.defaultdict(list)
@@ -76,6 +121,8 @@ def main():
   job_ranks = {}  # indexed by (job_id, task_id, alt_id).
   job_ends = []  # indexed by job_id
 
+  #----------------------------------------------------------------------------
+  # Scan the jobs and create the relevant variables and intervals.
   for job_id in all_jobs:
     job = jobs[job_id]
     num_tasks = len(job)
@@ -223,6 +270,7 @@ def main():
   # Solve.
   solver = cp_model.CpSolver()
   solver.parameters.max_time_in_seconds = 60 * 60 * 2
+  solver.parameters.num_search_workers = 8
   solution_printer = SolutionPrinter(makespan)
   status = solver.SolveWithSolutionCallback(model, solution_printer)
 
@@ -238,6 +286,9 @@ def main():
         rank = -1
 
         for alt_id in range(len(jobs[job_id][task_id])):
+          if jobs[job_id][task_id][alt_id][0] == -1:
+            continue
+
           if solver.BooleanValue(job_presences[(job_id, task_id, alt_id)]):
             duration = jobs[job_id][task_id][alt_id][0]
             machine = jobs[job_id][task_id][alt_id][1]