基础 Job Shop¶
基础 Job Shop¶
每个工件按固定工序访问指定机器，工序之间有先后关系，同一机器上的工序
不能重叠，目标通常是最小化最大完工时间。job_shop_small.py 使用统一
ModelBuilder 的 interval、no_overlap 和 precedence 表达这些约束，
适合作为固定机器调度的最小模型。
完整代码¶
examples/scheduling/job_shop_small.py
from __future__ import annotations
from pathlib import Path
import sys
from optagent import ModelBuilder, solve
sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
from _common import print_solution
def build_model() -> tuple[object, dict[str, int]]:
builder = ModelBuilder(metadata={"case": "job_shop_small"})
machine_a = builder.sequence_var(size=2, default=[0, 1], name="machine_a")
machine_b = builder.sequence_var(size=2, default=[0, 1], name="machine_b")
job1_a = builder.interval_var(start=0, length=2, lb_start=0, ub_start=8, lb_length=2, ub_length=2, name="job1_a")
job1_b = builder.interval_var(start=0, length=3, lb_start=0, ub_start=10, lb_length=3, ub_length=3, name="job1_b")
job2_b = builder.interval_var(start=0, length=2, lb_start=0, ub_start=8, lb_length=2, ub_length=2, name="job2_b")
job2_a = builder.interval_var(start=0, length=2, lb_start=0, ub_start=10, lb_length=2, ub_length=2, name="job2_a")
builder.constraint(builder.no_overlap(machine_a, job1_a, job2_a), name="machine_a_capacity")
builder.constraint(builder.no_overlap(machine_b, job1_b, job2_b), name="machine_b_capacity")
builder.constraint(builder.precedence(job1_a, job1_b, lag=0), name="job1_flow")
builder.constraint(builder.precedence(job2_b, job2_a, lag=0), name="job2_flow")
builder.minimize(builder.max(builder.interval_end(job1_b), builder.interval_end(job2_a)), name="makespan")
return builder.freeze(), {"machine_a": machine_a.node_id, "machine_b": machine_b.node_id}
def main() -> None:
program, sequence_ids = build_model()
solution = solve(program, time_limit_s=10.0, seed=7, threads=1, log_level="on")
print_solution("small job shop solved by unified solve", solution, extra={"machine_sequences": sequence_ids})
if __name__ == "__main__":
main()