Just-in-Time Manufacturing: How It Differs from Lean

If you’re familiar with the landscape of today’s manufacturing industry, you’ve likely heard of lean manufacturing. But have you heard of its relative, Just-In-Time Manufacturing? To many in the industry, Just-In-Time or JIT manufacturing and lean seem to be one and the same. But these two manufacturing philosophies actually do have some differences. And here, we’ll explain them in detail.

The core difference between lean and JIT is that lean focuses on the customer while JIT focuses on the business side of the manufacturing process. So, to make it simple and memorable:

• Lean manufacturing is a customer-centric philosophy
• JIT manufacturing is a business-centric philosophy

With that in mind, let’s take a look at what each process actually accomplishes:

Lean Manufacturing

Companies that implement lean manufacturing are aiming to do the following:

• Eliminate wasteful materials and processes
• Streamline production
• Provide customers with the most value for their dollar

In lean, waste typically refers to inventory. So, rather than keeping best-selling products in stock, manufacturers produce products as they are ordered. This simple step reduces production time and costs which results in a more satisfied customer.

Ultimately, the end goal in lean manufacturing is to improve production for the sake of keeping the customer happy and coming back for more.

JIT Manufacturing

JIT is a philosophy of continuous improvement that strives to achieve world class manufacturing. A strong JIT manufacturing operation should be able to accomplish three important things:

• Eliminate waste
• Remove variability
• Improve throughput

In JIT manufacturing, as in lean, waste is anything that does not add value from the customer’s point of view. So, in this case, things like product storage, inspections, delays, or defective products would be considered waste.

Removing variability is another essential component of JIT. This entails identifying and doing away with anything that deviates from what’s considered optimal. Some sources of variability include inaccurate or incomplete product specifications, unknown customer demands, and poor production processes.

When waste and variability are no longer concerns, improving throughput becomes much easier. Typically, throughput improvement involves optimizing the time it takes to move an order through the production process.

Altogether, what you have with JIT is a management philosophy that encourages forced problem solving and a ‘do it right the first time’ attitude in order to achieve the best possible results.