SIM07 · 起源 / 丰田从月计划拆到每日混流序列SIM07 · Origin / Toyota turned monthly plans into daily mixed-model sequences
客户按 ABAB 取货，为什么产线还排 AAAABBBB？If the customer pulls ABAB, why schedule the line as AAAABBBB?
生产平准化不是把月产量平均除到每天就结束了，还要把品种按客户需求节奏排进每个节拍。本页把换型时间设为 0，前提是已经通过 SIM05 快速换模 把换型压短；否则频繁混流只会把停机放大。Heijunka is not finished when monthly volume is divided evenly across the days. Product mix must also be sequenced into each Takt slot in the order customers pull it. This simulation sets changeover time to zero, assuming SIM05 SMED has already made changeovers fast enough for mixed-model production.
🎬 盯住取货小车：要 B 时只有 A，缺货就会红闪🎬 Watch the pickup cart: when it needs B but finds only A, the dock flashes red
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A 蓝件A · blueB 橙件B · orange红闪=缺货Red flash = stockout
💡 跑完看数据：总量一样，品种顺序错了照样缺货💡 Run it, then read the numbers: the total can match while the sequence still causes stockouts
两种排程由同一 DES 的 stats() 计算Both schedules come from the same DES stats()| 排程Schedule | 160 秒产量Output / 160 sec | 缺货次数Stockouts | 最高积压Peak inventory | 成功取货Filled pickups |
|---|---|---|---|---|
| AAAABBBB | — | — | — | — |
| ABABABAB | — | — | — | — |
读数边界：最高积压是任一时刻完成区 A+B 的总件数；缺货是取货节拍到点、所需型号库存为 0。换型时间固定为 0，不把 SMED 收益重复算进平准化。Measurement boundary: peak inventory is the highest combined A+B finished-goods count. A stockout occurs when the pickup beat arrives and the requested model is unavailable. Changeover stays at zero, so SMED benefit is not counted twice.
🎯 排程规则🎯 Scheduling rule
平准化不是“平均做”，而是按客户的品种和节奏排着做。Heijunka does not mean “make the average.” It means sequence the mix to the customer's pull.
⚠ 常见误区⚠ Common mistakes
✗ 连着做同型号才高效✗ Long runs of one model are always more efficient
✓ 客户不是连着买同一种；局部省换型，可能换来缺货和积压。✓ Customers do not buy in long single-model runs. Saving local setups can create stockouts and inventory elsewhere.
✗ 平准化就是平均分配产量✗ Leveling only means averaging the volume
✓ 还要按需求节奏排序品种，形成稳定混流。✓ The product mix must also be sequenced to demand, creating a stable mixed-model flow.
✗ 不换模就直接上混流✗ Start mixed-model production before fixing changeover
✓ 先做快速换模（SMED），平准化才跑得动。✓ Shorten changeovers with SMED first; then mixed-model leveling becomes practical.