Mapping A Path To Lean Manufacturing

We are hearing more and more about lean manufacturing these days. Our customers are telling us to get "lean" so we can both benefit.

Columns From: 10/1/2002 Modern Machine Shop,

We are hearing more and more about lean manufacturing these days. Our customers are telling us to get "lean" so we can both benefit. Our suppliers are telling us they are getting "lean" to serve us better. Even other companies in town are espousing the virtues of being "lean". Okay, we get it, but how do we start our journey toward lean manufacturing?

The answer is there are many ways to begin. However, before we do, let's make sure we understand the true meaning of lean manufacturing—it is the elimination of waste in the process. A lean manufacturing process is one that continuously strives to eliminate waste, thereby increasing the percentage of time devoted to value-adding activities. The more value you can add in your overall process, the more effective your operation will be. As long as you focus your efforts on waste elimination, you are on your way.

There are many techniques that will help you to eliminate waste in your organization. For one, creating manufacturing cells can eliminate the wastes of material handling, excessive motion, work-in-process inventory and more. Employing Total Productive Maintenance (TPM) can eliminate the wastes of unplanned downtime, waiting, defective parts and others. Even changing the layout of the plant will often eliminate the wastes of transportation, over-production, unnecessary processing and other wastes.

These are all excellent techniques, but we may not be applying them to the right areas of the business unless we have looked at our company's value stream—all of the activities that take place from order acceptance to the customer's receipt of the product. So to start our journey to lean manufacturing, we should think about a technique called value stream mapping.

Value stream mapping is a visual technique for describing how a business currently operates (and could operate). A value stream map is divided into two sections—the flow of information and the flow of material. In most businesses, these are of equal importance, but they do not always get the same level of attention. Information flow is often overlooked, or given just a passing glance, yet without an effective information flow, there can be no material flow.

In their book Learning To See, authors Mike Rother and John Shook effectively describe the mechanics of value stream mapping. Rather than focus on the mechanics of creating a value stream map, I want to discuss the usefulness of this technique to any enterprise.

One of the first things you notice when completing a value stream map of your current operation is how eye-opening an experience this can be, especially if you complete the map with a cross-functional team of people from the organization (which is the best way to go about this effort). It is amazing how things that many of us think are common knowledge are complete revelations to others. So the first benefit of the process is creating a common understanding of just how and when things occur.

Once you have generated a value stream map, problem areas stand out very clearly. You will see places where inventory is building up, both before and after production processes. You will see where long machine setup times and unplanned downtime are an impediment to flow. You will see evidence of unbalanced labor, or machine time, between processes creating delays. You will see how low first pass yield rates in certain processes drastically curtail the entire process flow. You will see just how many areas of the company schedule and expedite the production process. You will also see how the rate of customer demand equates to your rate of production. In short, you will easily identify the place, or places, in the value stream where you will need to start your waste elimination efforts.

Once you have completed the value stream map for your current operation, you will be able to visualize how things could operate. This vision will be the basis of your future value stream map. In this value stream map, you will have the ability to eliminate processes that add no value and combine or streamline those that do. You will highlight areas where your suppliers can provide better services. You will eliminate redundant and unnecessary information flows. All of these changes will support your organization's goal of providing the highest level of service to your customers.

Value stream mapping is a simple, yet powerful tool that anyone can employ. Generating current and future value stream maps and combining them with a detailed plan to transition from one to the other is an ideal way to begin your company's lean transformation.

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