.

shifts.py

@@ -31,7 +31,7 @@ bank_holidays = BankHolidays()
 bank_holiday_map = {}
 for bank_holiday in bank_holidays.get_holidays():
     bank_holiday_map[bank_holiday['date']] = bank_holiday['title']
-# see BankHolidays source file for more methods and arguments…
+# see BankHolidays source file for more methods and arguments
 
 
 class SingleShift(object):
@@ -92,7 +92,9 @@ class RotaBuilder(object):
                  balance_offset_modifier=1,
                  ltft_balance_offset=4,
                  max_night_frequency=2,
-                 max_weekend_frequency=2):
+                 max_weekend_frequency=2,
+                 use_previous_shifts=True,
+                 ):
 
         print("Start time: {}".format(datetime.datetime.now()))
 
@@ -104,6 +106,8 @@ class RotaBuilder(object):
 
         self.weeks_days_product = list(itertools.product(self.weeks, days))
 
+        self.use_previous_shifts = use_previous_shifts
+
         if start_date.weekday() != 0:
             raise ValueError("Start date {} must be a Mon (not a {})".format(
                 start_date.isoformat(), days[start_date.weekday()]))
@@ -644,6 +648,12 @@ class RotaBuilder(object):
                                      full_time_equivalent_joined *
                                      worker.fte_adj)
 
+                    if self.use_previous_shifts:
+                        if shift in worker.previous_shifts:
+                            worked, allocated = worker.previous_shifts[shift]
+                            target_shifts = target_shifts + allocated - worked
+
+
                     worker.shift_target_number[shift.name] = target_shifts
 
                     if shift.hard_constrain_shift: