Server overtime implemented

Author: geraintpalmer

ciw/node.py

@@ -48,6 +48,7 @@ def __init__(self, id_, simulation):
             self.simulation.network.number_of_classes)]
         if self.schedule:
             self.next_event_date = self.next_shift_change
+            self.overtime = []
         else:
             self.next_event_date = float("Inf")
         self.blocked_queue = []
@@ -330,6 +331,8 @@ def kill_server(self, srvr):
         Kills server.
         """
         srvr.total_time = self.increment_time(self.next_event_date, -srvr.start_date)
+        self.overtime.append(
+            self.increment_time(self.next_event_date, -srvr.shift_end))
         self.all_servers_busy.append(srvr.busy_time)
         self.all_servers_total.append(srvr.total_time)
         indx = self.servers.index(srvr)
@@ -394,13 +397,15 @@ def take_servers_off_duty(self):
         if not self.preempt:
             to_delete = []
             for srvr in self.servers:
+                srvr.shift_end = self.next_event_date
                 if srvr.busy:
                     srvr.offduty = True
                 else:
                     to_delete.append(srvr)
         else:
             to_delete = self.servers[::1]  # copy
             for s in self.servers:
+                s.shift_end = self.next_event_date
                 if s.cust is not False:
                     self.interrupted_individuals.append(s.cust)
                     self.interrupted_individuals[-1].service_end_date = False

ciw/server.py

@@ -17,6 +17,7 @@ def __init__(self, node, id_number, start_date=0.0):
         self.start_date = start_date
         self.busy_time = False
         self.total_time = False
+        self.shift_end = False
 
     @property
     def utilisation(self):

ciw/tests/test_scheduling.py

@@ -1,5 +1,7 @@
 import unittest
 import ciw
+from decimal import Decimal
+
 
 class TestScheduling(unittest.TestCase):
 
@@ -251,3 +253,30 @@ def test_full_preemptive_simulation(self):
         # finishing at time 12.5 (total: 9.5 time units). Then server goes off duty
         # for 4.5 time units (total: 14 time units). Then resample service time and
         # get serviced for another 10 time units (total: 24 time units).
+
+
+    def test_overtime(self):
+        N = ciw.create_network(
+            Arrival_distributions=[['Sequential', [1.0, 0.0, 0.0, 8.0, 0.0, 3.0, 10000.0]]],
+            Service_distributions=[['Sequential', [5.0, 7.0, 9.0, 4.0, 5.0, 5.0]]],
+            Number_of_servers=[([[3, 7.0], [2, 11.0], [1, 20.0]], False)]
+        )
+        Q = ciw.Simulation(N)
+        Q.simulate_until_max_time(19.0)
+
+        nd = Q.transitive_nodes[0]
+        self.assertEqual(nd.overtime, [0.0, 1.0, 3.0, 2.0, 3.0])
+        self.assertEqual(sum(nd.overtime)/len(nd.overtime), 1.8)
+
+    def test_overtime_exact(self):
+        N = ciw.create_network(
+            Arrival_distributions=[['Sequential', [1.0, 0.0, 0.0, 8.0, 0.0, 3.0, 10000.0]]],
+            Service_distributions=[['Sequential', [5.0, 7.0, 9.0, 4.0, 5.0, 5.0]]],
+            Number_of_servers=[([[3, 7.0], [2, 11.0], [1, 20.0]], False)]
+        )
+        Q = ciw.Simulation(N, exact=26)
+        Q.simulate_until_max_time(19.0)
+
+        nd = Q.transitive_nodes[0]
+        self.assertEqual(nd.overtime, [Decimal('0.0'), Decimal('1.0'), Decimal('3.0'), Decimal('2.0'), Decimal('3.0')])
+        self.assertEqual(sum(nd.overtime)/len(nd.overtime), Decimal('1.8'))