Operations management (A Level)
A-Level Business Topic 9 7:46 English narration · English + 中文 subtitles burned in
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Transcript
A company promised its new factory in a hundred and fifteen weeks.
一家公司承诺一百一十五周建成新工厂。
It opened thirty weeks late, at a huge cost in wages and rent.
结果晚了三十周， 在工资和租金上付出了巨大代价。
One task slipped in the middle, and it was the wrong one.
项目中间有一项任务延误了， 而且延误的正是不该延误的那一项。
Operations management decides where to build, how big, and how to finish on time.
运营管理要决定在哪里建厂、建多大，以及如何按时完工。
Here is the plan.
这是本节的安排。
Where to put the business, and how big to grow it.
企业设在哪里，以及要发展到多大。
Then quality, and four ways to manage it.
然后是质量，以及管理质量的四种方法。
Then lean production, capacity and technology.
接着是精益生产、产能与技术。
And last, critical path analysis, which finds the tasks that must never be late.
最后是关键路径分析，它找出绝不能延误的任务。
Where should the business be?
企业应该设在哪里？
Choosing a place is called location; moving is relocation.
选择一个地点叫做选址，搬到新地点叫做迁址。
Quantitative factors are measured in money: rent, wages, transport, grants.
定量因素可以用钱来衡量：租金、工资、运输、补助。
Qualitative factors are harder to measure: worker skills, nearness to customers, the owner's wishes.
定性因素较难衡量：工人技能、离顾客的远近、所有者自己的想法。
The firm picks the site with the greatest total benefit, money reasons and the rest together.
企业会选择总收益最大的地点，把用钱衡量的理由和其他理由一起算进去。
Transport cost pulls hardest of all.
运输成本的拉力最大。
Two raw materials sit at the top corners; the market is at the bottom.
两种原材料位于上方两角，市场在下方。
The strongest pull wins.
拉力最强的一方获胜。
If the raw material is bulky and the product light, build near the materials.
如果原材料笨重而产品轻，就把工厂建在原材料附近。
If the product is the bulky one, build near the market.
如果笨重的是产品，就把工厂建在市场附近。
Many firms look abroad.
许多企业把目光投向海外。
Moving production to another country is called offshoring.
把生产转移到另一个国家叫做离岸外包。
Why do firms do it?
企业为什么这样做？
Wages are lower, the firm sits closer to a new market, and a government may help.
工资更低，企业离新市场更近，政府也可能提供帮助。
The risks are real too: long supply lines, culture gaps, brand damage.
风险同样真实：供应链变长、文化差异、品牌受损。
Offshoring is a trade-off: weigh the saving against the risk.
离岸外包是一种取舍：要把省下的钱和风险放在一起权衡。
How big should the firm be?
企业应该做到多大？
Watch the average cost of one unit as output rises.
看看随着产量上升，每一件产品的平均成本如何变化。
At first it falls: fixed overheads are spread over more units, and a bigger firm buys in bulk.
一开始它下降：固定间接成本被分摊到更多产品上，而且更大的企业可以批量采购。
That is economies of scale.
这就是规模经济。
Grow too far and cost per unit rises again, as communication slows.
长得太大，单位成本又会上升，因为沟通变慢。
That is diseconomies of scale.
这就是规模不经济。
Put both forces on one curve and you get this U shape.
把这两种力量画在一条曲线上，就得到这个U形。
Cost falls while the firm is too small to spread its overheads.
企业太小、无法分摊间接成本时，成本一直下降。
It reaches a lowest point, then rises when the firm is too big to manage well.
它降到最低点， 然后在企业大到难以管好时又上升。
That lowest point is the optimum scale: where average cost per unit is smallest.
那个最低点就是最优规模： 单位平均成本最小的规模。
Grow up to it, not past it.
发展到它为止，不要超过。
Quality means how well a product meets the customer's needs; good quality keeps customers and cuts waste.
质量是指产品在多大程度上满足顾客的需要；好的质量留住顾客，也减少浪费。
Four methods, by name.
四种方法，名字都要记住。
Quality control checks the finished goods and removes the faulty ones at the end.
质量控制在最后检查成品，把有缺陷的挑出来。
Quality assurance builds quality into every stage, so faults are prevented.
质量保证把质量做进每一道工序，让缺陷被预防。
Total quality management, TQM, goes further: every worker aims at zero faults.
全面质量管理（TQM）更进一步：每一位工人都以零缺陷为目标。
Benchmarking compares the firm with the best.
标杆管理把本企业与最好的企业作比较。
Now see where the check happens.
现在看看检查发生在什么位置。
On the top line, quality control lets the work reach the end before anyone inspects it.
上面这条线是质量控制： 产品一路走到最后，才有人检查。
The fault is found, but the material and labour are already spent.
缺陷是找到了，但材料费和人工费都已经花掉了。
On the bottom line, quality assurance puts a check after every stage, so a fault is caught while it is cheap to fix.
下面这条线是质量保证：每一道工序之后都有一次检查， 缺陷在还便宜就能修好的时候就被发现。
Lean production means the least possible waste: waste of time, stock, space and effort.
精益生产是指浪费尽可能少：时间、存货、空间和人力的浪费。
Two named methods do most of the work.
两种有名的方法承担了大部分工作。
Just-in-time means stock arrives only when it is needed.
准时制是指存货只在需要时才到达。
Kaizen means continuous improvement, many small changes by the workers.
持续改善是指不断改进，来自工人的许多小改动。
The payoff is lower cost and less cash tied up in stock.
好处是成本更低，压在存货上的现金更少。
Stock is the cash lean production wants back.
存货就是精益生产想要收回的现金。
Watch the stock level fall day by day.
看着存货水平一天天下降。
At the reorder level, the order goes in.
降到再订货点时，订单就发出去。
The wait for delivery is the lead time.
等待交货的这段时间叫做提前期。
Delivery lands as the stock touches the buffer, and the pattern repeats, so stock never runs out.
交货正好在存货碰到安全存货时到达，然后这个形状不断重复，所以存货永远不会断。
Capacity management means matching what a firm can produce to the demand it faces.
产能管理是指让企业能够生产的数量与它面对的需求相匹配。
If demand is above capacity, add shifts, hire, or outsource.
如果需求高于产能，就加班次、招人，或者外包。
If demand is below capacity, cut output or win new orders.
如果需求低于产能，就减产，或者争取新订单。
New technology sits behind both: automation lifts output, quality and cost together, but costs a lot to install.
新技术在这两件事的背后：自动化同时提升产量、质量和成本表现，但安装成本很高。
A project is many tasks, and some wait for others.
一个项目由许多任务组成，其中一些要等另一些完成。
Critical path analysis lists every activity, its length, and what it follows.
关键路径分析列出每一项活动、它的时长，以及它要跟在什么后面。
Clearing the site takes forty weeks.
清理场地需要四十周。
Building the plant takes sixty.
建厂房需要六十周。
Ordering the machines takes twenty, delivery thirty more.
订购机器需要二十周，运到再需要三十周。
Installing them takes ten weeks, and training the staff takes five.
安装机器需要十周，培训员工需要五周。
Now draw it as a network.
现在把它画成网络图。
Each circle is a moment in time; each arrow an activity.
每个圆圈是一个时间点，每支箭头是一项活动。
Building the plant and the machines run side by side.
建厂房和把机器弄到手是并行的。
Work forwards, left to right, writing the earliest start time in each circle's top half.
从左到右向前推算， 把最早开始时间写在每个圆圈的上半格。
Where two arrows meet, take the larger number: wait for the slower path.
两支箭头汇合的地方，取较大的数： 要等那条较慢的路径。
The last circle reads a hundred and fifteen, the earliest the project can finish.
最后一个圆圈是一百一十五，这就是项目最早能完工的时间。
Now go backwards, right to left, writing the latest finish time in the bottom half: the latest it can end without delaying the project.
现在从右到左往回推算，把最晚完成时间写在下半格： 这是它最晚能结束、又不会让项目延期的时间。
Where two arrows leave a circle — a node — take the smaller number.
两支箭头从一个圆圈（节点）出发的地方，取较小的数。
Every activity now has spare time, called the total float: the latest finish time, minus the duration, minus the earliest start time.
现在每项活动都有一段富余时间， 叫做总浮动时间：最晚完成时间，减去持续时间，再减去最早开始时间。
Activities with zero float form the critical path.
浮动时间为零的活动构成关键路径。
They cannot slip a single week.
它们一周也不能拖。
Your handout draws the same idea, smaller.
你的讲义把同样的思路画得更小。
Read the key first: green on top is the earliest start time, blue below is the latest finish time, orange arrows mark the critical path.
先看图例：上方绿色数字是最早开始时间， 下方蓝色数字是最晚完成时间，橙色箭头标出关键路径。
Activity C is not on it: its latest finish is eight, its duration three, its earliest start four, so its float is one week.
活动C不在上面：它的最晚完成时间是八，持续时间是三，最早开始时间是四， 所以浮动时间是一周。
And here is the trap: shortening a non-critical task like C does not shorten the project at all.
这里有个陷阱：缩短像C这样的非关键任务，根本不会缩短整个项目。
The last circle says thirteen, so the project takes thirteen weeks.
最后一个圆圈写着十三，所以项目需要十三周。
A network is only as good as its estimates.
而网络图的好坏完全取决于时间估计。
Now a real exam question from November twenty twenty-five: calculate the total float for activity C, and the minimum project duration.
现在是一道真实的考题，来自二零二五年十一月：计算活动C的总浮动时间， 以及最短项目工期。
Pause and try it yourself.
先暂停，自己试一试。
For C, the latest finish time is seventy, the duration twenty, the earliest start forty.
活动C的最晚完成时间是七十，持续时间是二十，最早开始时间是四十。
Seventy minus twenty minus forty gives ten weeks.
七十减二十再减四十，得到十周。
So C can start ten weeks late and still finish on time.
所以C可以晚十周开始，项目仍然按时完工。
Then add the durations along the critical path: forty, sixty, ten and five.
然后把关键路径上的持续时间加起来：四十、六十、十和五。
That is a hundred and fifteen weeks, so always write the units too.
结果是一百一十五周，而且一定要写上单位。
Three marks students lose.
三个学生常丢的分。
First, when you compare quality methods, say when the check happens: control inspects at the end, assurance at every stage.
第一，比较质量管理方法时，要说清楚检查发生在什么时候： 质量控制在最后检验，质量保证在每一道工序。
Second, never explain lean production without naming a method, like just-in-time or kaizen.
第二，讲精益生产时一定要点出具体方法，比如准时制或持续改善。
Third, on a network, show the working: only zero float is critical.
第三，在网络图上要写出计算过程：只有浮动时间为零才是关键活动。
Four things to take away.
四点要带走。
Location: weigh the quantitative and the qualitative factors, and remember offshoring.
选址：权衡定量因素和定性因素，并记住离岸外包。
Optimum scale: the lowest average cost.
最优规模：平均成本最低的规模。
Quality: control finds the fault late; assurance and total quality management prevent it.
质量：质量控制发现缺陷太晚；质量保证和全面质量管理是预防。
And the critical path has zero float, so it sets the project's length.
还有关键路径的浮动时间为零，它决定项目的长度。