How to Identify Manufacturing Bottlenecks

From a busy intersection at rush hour to security check-ins at airports, we’re surrounded by bottlenecks. In real-world scenarios, since most of us are forced to navigate bottlenecks every day, it’s easy to forget how costly they can be to businesses.

Of course, nowhere is the impact of bottlenecks more closely tied to cash flow than in the manufacturing industry. Whether they cause an overstock of supplies or lag times in production, bottlenecks always result in reduced performance for manufacturers of all sizes in a number of production systems.

As Chris Castaldi points out in “Eliminating Bottlenecks in the Supply Chain” for Apparel Magazine, bottlenecks exist regardless of how well your employees and machinery are working. That’s why it’s worthwhile for manufacturers to know how to accurately identify bottlenecks in production: So they can take appropriate measures to avoid the costliest ones whenever and wherever they occur. The process of identifying bottlenecks is also referred to as a bottleneck analysis.

Manufacturing Bottlenecks

Just as the slim neck on a bottle of wine limits how much of its contents can pour out at a given time, a manufacturing bottleneck is a process or step that limits an entire system’s capacity to produce — otherwise known as “throughput.”

To illustrate this concept, imagine you have a four-step production line with the following capacity:

• Step 1: Processes 75 items per hour.
• Step 2: Processes 75 items per hour.
• Step 3: Processes 80 items per hour.
• Step 4: Processes 60 items per hour.

In this example, your throughput is clearly limited by the bottleneck in step four. Yet, if you were able to increase step four’s capacity to equal that of step three, you would still be left with two equal bottlenecks at steps one and two. In other words, there will always be bottlenecks in manufacturing as well as opportunities to improve them.

How to Find the Bottleneck in a Process

Naturally, the example above is an oversimplification of what is, more often than not, a series of multiple and complex manufacturing processes. This is why, as LEAN Manufacturing Japan points out, if you don’t accurately recognize where a bottleneck — also referred to as a “constraint” — exists, you can miss out on the chance to increase your throughput.

To recognize and measure bottlenecks in manufacturing, look at the following three aspects of your production line:

• Accumulation: Whenever the input of items happens faster than a given process, accumulation occurs. Especially when individual items are processed sequentially, the place in your production line with the greatest accumulation is likely to be a bottleneck that needs improvement.
• Throughput: In his Houston Chronicle article, “How to Identify Bottlenecks in Manufacturing,” Bert Markgraf correctly recognizes that the output of each machine in a production line helps determine the overall throughput. Of course, it’s possible to change each machine’s output while keeping track of throughput. In this manner, throughput capacity will only increase when the machine that is the bottleneck experiences increased output.
• Capacity: Along with tracking each machine’s output, most manufacturers calculate each machine’s capacity. Following this method — sometimes referred to as the “Theory of Constraints,” or “TOC” — the machine that operates at the highest capacity typically causes other machines to operate at lower capacities and is, therefore, bottlenecking the other machines.

Want to Avoid Bottlenecks in Production? Choose MANTEC.

Undoubtedly, the best way to manage bottlenecks is to avoid them in the first place. This is accomplished through bottleneck analysis operations management, which is often tied to the adoption of LEAN manufacturing principles such as Six Sigma.

By eliminating wasteful practices and constantly looking to increase the efficiency of manufacturing processes by employing improvement tools such as value stream maps, manufacturers can correct existing bottlenecks as well as take steps to avoid future ones from occurring.

While process improvement can be challenging, it’s important to realize that it’s attainable with the right support — like operational excellence services from MANTEC. As a private, non-profit 501 (c) 3, we’ve been helping small to medium manufacturers in South Central Pennsylvania recognize and overcome their bottlenecks since 1988. And we can do the same for your business. Simply call us at 717-843-5054 or contact us today.