JobShopLib¶

Version: 1.7.0

JobShopLib is a Python package for creating, solving, and visualizing job shop scheduling problems.

It provides solvers based on:

Graph neural networks (Gymnasium environment)
Dispatching rules
Simulated annealing
Constraint programming (CP-SAT from Google OR-Tools)

It also includes utilities for:

Load benchmark instances
Generating random problems
Gantt charts
Disjunctive graphs (and any variant)
Training a GNN-based dispatcher using reinforcement learning or imitation learning

JobShopLib's design is intended to be modular and easy-to-use:

import matplotlib.pyplot as plt
plt.style.use("ggplot")

from job_shop_lib import JobShopInstance, Operation
from job_shop_lib.benchmarking import load_benchmark_instance
from job_shop_lib.generation import GeneralInstanceGenerator
from job_shop_lib.constraint_programming import ORToolsSolver
from job_shop_lib.visualization import plot_gantt_chart, create_gif, plot_gantt_chart_wrapper
from job_shop_lib.dispatching import DispatchingRuleSolver

# Create your own instance manually,
job_1 = [Operation(machines=0, duration=1), Operation(1, 1), Operation(2, 7)]
job_2 = [Operation(1, 5), Operation(2, 1), Operation(0, 1)]
job_3 = [Operation(2, 1), Operation(0, 3), Operation(1, 2)]
jobs = [job_1, job_2, job_3]
instance = JobShopInstance(jobs)

# load a popular benchmark instance,
ft06 = load_benchmark_instance("ft06")

# or generate a random one.
generator = GeneralInstanceGenerator(
    duration_range=(5, 10), seed=42, num_jobs=5, num_machines=5
)
random_instance = generator.generate()

# Solve it using constraint programming,
solver = ORToolsSolver(max_time_in_seconds=10)
ft06_schedule = solver(ft06)

# Visualize the solution as a Gantt chart,
fig, ax = plot_gantt_chart(ft06_schedule)
plt.show()

# or visualize how the solution is built step by step using a dispatching rule.
mwkr_solver = DispatchingRuleSolver("most_work_remaining")
plt.style.use("ggplot")
plot_function = plot_gantt_chart_wrapper(
    title="Solution with Most Work Remaining Rule"
)
create_gif(  # Creates the gif above
    gif_path="ft06_optimized.gif",
    instance=ft06,
    solver=mwkr_solver,
    plot_function=plot_function,
    fps=4,
)

See this Google Colab notebook for a quick start guide!

Installing¶

pip install job_shop_lib

JobShopLib¶

Installing¶

Contents¶