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polish baking example

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This commit is contained in:
Laurent Perron
2022-03-28 17:44:33 +02:00
parent 5d7f0e33ee
commit 7c729cbd6e
1 changed files with 31 additions and 27 deletions
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58
examples/python/no_wait_baking_scheduling_sat.py
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@@ -29,7 +29,7 @@ from ortools.sat.python import cp_model
FLAGS = flags.FLAGS
flags.DEFINE_string('params', 'num_search_workers:16, max_time_in_seconds:60',
flags.DEFINE_string('params', 'num_search_workers:16, max_time_in_seconds:30',
'Sat solver parameters.')
flags.DEFINE_string('proto_file', '',
'If not empty, output the proto to this file.')
@@ -54,7 +54,7 @@ class Task(object):
- Simple baking tasks have a fixed duration. They are performed by workers.
- Waiting/cooling/proofing tasks have a min and a max duration.
They are performed by machine or space resources.
They are performed by machine or they use space resources.
"""
def __init__(self, name, min_duration, max_duration):
@@ -64,16 +64,16 @@ class Task(object):
class Skill(object):
"""The skill of a worker, of the capability of a machine."""
"""The skill of a worker or the capability of a machine."""
def __init__(self, name, efficiency):
self.name = name
# Efficienty is currently not used.
# Efficiency is currently not used.
self.efficiency = efficiency
class Recipe(object):
"""A recipe is a set of cooking tasks."""
"""A recipe is a sequence of cooking tasks."""
def __init__(self, name):
self.name = name
@@ -113,7 +113,7 @@ class Order(object):
Args:
unique_id: A unique identifier for the order. Used to display the result.
recipe_name: The name of the recipe. It must match one of the recipe.
recipe_name: The name of the recipe. It must match one of the recipes.
due_date: The due date in minutes since midnight.
quantity: How many cakes to prepare.
"""
@@ -160,9 +160,9 @@ def set_up_data():
baker1 = Resource('baker1', 1).add_skill(BAKING, 1.0)
baker2 = Resource('baker2', 1).add_skill(BAKING, 1.0)
decorator1 = Resource('decorator1', 1).add_skill(DECORATING, 1.0)
waiting_space = Resource('waiting_space', 10).add_skill(PROOFING, 1.0)
oven = Resource('oven', 10).add_skill(COOKING, 1.0)
display_space = Resource('display_space', 10).add_skill(DISPLAY, 1.0)
waiting_space = Resource('waiting_space', 4).add_skill(PROOFING, 1.0)
oven = Resource('oven', 4).add_skill(COOKING, 1.0)
display_space = Resource('display_space', 12).add_skill(DISPLAY, 1.0)
resources = [baker1, baker2, decorator1, waiting_space, oven, display_space]
# Orders
@@ -171,10 +171,10 @@ def set_up_data():
croissant_9am = Order('croissant_9am', CROISSANT, 9 * 60, 2)
croissant_10am = Order('croissant_10am', CROISSANT, 10 * 60, 1)
croissant_11am = Order('croissant_11am', CROISSANT, 11 * 60, 1)
brioche_10am = Order('brioche_10am', BRIOCHE, 10 * 60, 4)
brioche_12pm = Order('brioche_12pm', BRIOCHE, 12 * 60, 4)
brioche_10am = Order('brioche_10am', BRIOCHE, 10 * 60, 8)
brioche_12pm = Order('brioche_12pm', BRIOCHE, 12 * 60, 8)
apple_pie_1pm = Order('apple_pie_1pm', APPLE_PIE, 13 * 60, 10)
chocolate_4pm = Order('chocolate_4pm', CHOCOLATE_CAKE, 16 * 60, 12)
chocolate_4pm = Order('chocolate_4pm', CHOCOLATE_CAKE, 16 * 60, 10)
orders = [
croissant_7am, croissant_8am, croissant_9am, croissant_10am,
croissant_11am, brioche_10am, brioche_12pm, apple_pie_1pm, chocolate_4pm
@@ -206,10 +206,9 @@ def solve_with_cp_sat(recipes, resources, orders):
# Parse orders and create one optional copy per eligible resource and per
# task.
interval_list_by_resource_name = collections.defaultdict(list)
orders_sequence = collections.defaultdict(list)
orders_sequence_of_events = collections.defaultdict(list)
sorted_orders = []
end_var_by_order_name = {}
sum_of_due_dates = 0
tardiness_vars = []
for order in orders:
for batch in range(order.quantity):
order_id = f'{order.unique_id}_{batch}'
@@ -225,7 +224,8 @@ def solve_with_cp_sat(recipes, resources, orders):
if previous_end is None:
start = model.NewIntVar(start_work, horizon,
f'start{suffix}')
orders_sequence[order_id].append(start)
orders_sequence_of_events[order_id].append(
(start, f'start{suffix}'))
else:
start = previous_end
@@ -233,10 +233,18 @@ def solve_with_cp_sat(recipes, resources, orders):
f'size{suffix}')
end = None
if task == recipe.tasks[-1]:
end = model.NewIntVar(due_date, horizon, f'end{suffix}')
# The order must end after the due_date. Ideally, exactly at the
# due_date.
tardiness = model.NewIntVar(0, horizon - due_date,
f'end{suffix}')
end = tardiness + due_date
# Store the end_var for the objective.
tardiness_vars.append(tardiness)
else:
end = model.NewIntVar(start_work, horizon, f'end{suffix}')
orders_sequence[order_id].append(end)
orders_sequence_of_events[order_id].append(
(end, f'end{suffix}'))
previous_end = end
# Per resource copy.
@@ -253,10 +261,6 @@ def solve_with_cp_sat(recipes, resources, orders):
# Only one copy will be performed.
model.AddExactlyOne(presence_literals)
# Store the end of the order for the objective.
end_var_by_order_name[order_id] = previous_end
sum_of_due_dates += due_date
# Create resource constraints.
for resource in resources:
intervals = interval_list_by_resource_name[resource.name]
@@ -269,7 +273,7 @@ def solve_with_cp_sat(recipes, resources, orders):
# The objective is to minimize the sum of the tardiness values of each jobs.
# The tardiness is difference between the end time of an order and its
# due date.
model.Minimize(sum(end_var_by_order_name.values()) - sum_of_due_dates)
model.Minimize(sum(tardiness_vars))
# Solve model.
solver = cp_model.CpSolver()
@@ -278,12 +282,12 @@ def solve_with_cp_sat(recipes, resources, orders):
solver.parameters.log_search_progress = True
status = solver.Solve(model)
if status == cp_model.OPTIMAL:
if status == cp_model.OPTIMAL or status == cp_model.FEASIBLE:
for order_id in sorted_orders:
print(f'{order_id}:')
for var in orders_sequence[order_id]:
time = solver.Value(var)
print(f' {var.Name()} at {time // 60}:{time % 60:02}')
for time_expr, event_id in orders_sequence_of_events[order_id]:
time = solver.Value(time_expr)
print(f' {event_id} at {time // 60}:{time % 60:02}')
def main(argv: Sequence[str]) -> None: