How Lean and JIT are aligned with quality philosophy?

Module II. Process Quality Improvement

Lecture -5 How Lean and JIT are aligned with quality philosophy?

Just-in-time is a philosophy of continual improvement. Lean production process means supplying the customer with exactly what the customer wants, when the customer wants it, without waste, through continual improvement. Lean production is driven by "pull" system of the customer's order. JIT is one of the key ingredient of lean production. When implemented comprehensive manufacturing strategy, JIT and lean production sustain competitive advantage and result in greater overall returns.

With JIT, components are "pulled" through the system to arrive where they are needed and when they are needed. When units do not arrive just as needed, a "problem" is identified. This makes JIT an excellent tool to help operations managers add value by driving out waste and unwanted variability. Because there is no excess inventory or excess time in a JIT system, costs associated with unneeded inventory are eliminated and throughput is improved. Consequently, the benefits of JIT are particularly helpful in supporting strategies of rapid response at lower cost.

As elimination of waste and variability are fundamental to both JIT and lean production, a brief explanation on both is provided below.

Waste: It is anything that does not add value to customers. In other words, customers are not willing to pay for it. Products being stored, inspected or delayed, products waiting in queues, and defective products which do not add value are waste. Moreover, any activity that does not add value to a product from the customer's perspective is called waste. JIT provides faster delivery, reduces work-in-process, and speedy throughput. Additionally, because JIT reduces work-in-process, it provides little room for any errors, putting added emphasis on quality production. These waste reduction efforts improves productivity and processes.

Variability Reduction: To achieve just-in-time material movement, managers reduce variability caused by both internal and external factors in the process. Variability is any deviation in the standard process to deliver perfect product on time, every time. Reducing inventory, less waste in the system will ultimately reduce uncertainty. Most variability is caused by tolerating waste or bypoor inventory management or ineffective process. Variability occurs because:

(i) Employees. machines, and suppliers produce units that do not conform to standards,

(ii) Engineering drawings or specifications are inaccurate. It is rare event although.

(iii) Customer’s exact demands are unknown and improper design.

Variability can often go unseen when inventory exists. JIT philosophy is aligned with continual improvement by reducing such variability. The removal of variability allows us to move materials just-in-time for use. J1T implementation can reduce throughput time in a supply chain.

Quality improves as uncertainty decreases and variability reduces.