Organization in lines

All factories are not organized the same way. I have explained this concept to tens (hundreds?) of buyers. It is absolutely fundamental if you want to understand how production works.
Organization in lines
In most Chinese factories that export products to other countries, several operations are performed — often final assembly and packing.
Most people imagine that production is organized this way:

If one line counts 25 workers, and there are 20 lines, there is a total of 500 workers on the production floor.
Consequence of a line organization: the first finished products appear very fast (in less than 2 hours). And corrective actions can be taken early if quality problems are noticed.
Unfortunately, it is seldom that straightforward.
Sometimes we see this: packing is done at the last moment, when nearly all the products are finished.

But still, we can check quality early in the cycle. Not bad at all.
Organization in islands
This is the most common type of production organization in China. Most manufacturers here have a batch & queue mentality: “let’s focus on processing huge batches at a time, and we’ll be more efficient”.
So they gather all the similar machines together. One can see an “island” of cutting machines, then an “island” of overlock stitching machines, and so on.

So the first island works on your order for 2 or 3 days, then a second island starts processing your order, and then the third island, etc.
Problems with this type of organization:

• 
  The first finished products appear after 10 or 20 days. Some types of defects can only be noticed at that last stage. And repairing everything can take a long time.
  
• 
  If a customer asks for production samples, it is usually impossible to send these samples in time (since there are no finished products until late in the cycle), and they end up being made on other machines… Which means they are not representative of the average quality of the order.
  
• 
  Huge amount of work-in-process inventory that needs to be stored and moved around… And that might get damaged or lost.
  
• 
  Small orders frequently get lost in the inventory piles.
  

I already listed these problems in more details in this article.