Why choose Lean manufacturing
The second law of thermo-dynamics tells us that the entropy of a system will tend to increase over time. Also, it is only natural for a system to go from an orderly state to a more disorderly state. In manufacturing, or in other business processes, it is natural for inefficiencies and waste to make their way into the processes. Just as sediment builds up in your household drain pipes, left to themselves, a similar kind of sediment will build up in the manufacturing plant.
When waste and inefficiencies creep in over time to the manufacturing process, these can really add up to big losses over time. Toyota recognized that they could save a lot of money by reducing waste and came up with a methodology known as Lean manufacturing.
Why should you adopt the Lean manufacturing methodologies? The simple answer to this is that you will save money. By continuous process improvement and reducing waste in manufacturing processes, profits will go up and expenses will go down.
Kaizen is the Japanese concept of continuous improvement. Instead of waiting for a long period of time and redesigning a process from scratch, the idea is to make small incremental improvements as the needs arise. For example, let's say that one of the parts of a conveyor belt keeps wearing out and breaking causing downtime on the assembly line, instead of scrapping and redesigning the whole line, the principle of Kaizen would encourage you to figure out and improve that one aspect of the line that causing the downtime. Making small changes to processes cost less, take less time, and therefore can be done with less time and happen more often than by waiting until the process becomes completely obsolete and needs to be replaced with a completely reengineered process.
One of the main goals of Lean manufacturing is to eliminate waste. There are seven key wastes that Lean manufacturing would have you eliminate:
- Defects: When you purchase a DVD player from the store, it comes with a manufacturer's warranty. This is because they know that there will be a certain amount of defects in their product. When a faulty product occurs within a reasonable amount of time, the DVD player will be returned for a replacement. The defective product will be a complete loss to the manufacturer.
- Overproduction: By producing more items than can actually be sold, all the unsold items can potentially be an even more serious waste than defects. If possible, just-in-time manufacturing teaches that instead of anticipating the sales of a product, and storing them, that you should try to manufacture and deliver the product as needed. The key to making this work is to be able to make and deliver the product quickly. This brings us to the next item.
- Transportation: Damage from shipping is one of the wastes to be reduced.
- Waiting: When needed supplies for a department to make something have not yet arrived, then their time will be spent on something other than making the product.
- Inventory: This should be kept to a minimum.
- Motion: Moving parts, workers at risk, and other operations can add up to wasteful situations.
- Over-processing: Producing products, features, and quantities of items where there is no need is wasteful because they do not translate into profits.
These common sense principles if understood and followed by engineers, managers and employees will translate into waste reduction and increased profits.