Are bottlenecks keeping your operation from fulfilling its potential?
Bottlenecks—the steps in a process that govern the speed of the entire operation—are a common headache in the manufacturing world. Unlike the bottlenecks we experience in our daily lives, such as a broken-down car on the freeway making us late for work, production bottlenecks are not simple annoyances or inconveniences. On the contrary, in a business they can translate into significant opportunity loss if left untreated. Yet, while it’s often easy to identify a bottleneck on the shop floor, figuring out how to manage it is a much more complex undertaking. The root cause of a bottleneck is often buried deep inside a process and only becomes apparent through rigorous investigation and experimentation.
Consider the case of a high-end home furnishings manufacturer. The company was failing to meet its production targets for one of its most popular items because the manufacturing process of a key component was continually falling behind. Prior to final assembly, this component required significant amounts of sanding, painting, and buffing—a process that rarely went as smoothly as the company expected. In fact, the department responsible for this component regularly found itself having to rework, and sometimes even scrap the product due to a wide range of defects. Doing so not only slowed down the entire production process for the end product, but also cost the company hundreds of thousands of dollars in wasted labor and materials.
It was clear the paint department’s inability to consistently produce components that met the company’s quality standards was the bottleneck. What wasn’t so clear was the root cause of that inconsistency. Why were defects able to find their way onto the finished component despite workers’ best efforts to avoid them?
The company needed help and asked TriVista to find a solution. Our team first used Value Stream Maps and Pareto Analysis to assess the existing process to track the number and types of defects produced over a four week timeframe. This in-depth analysis revealed that dust particles in the paint was the single-biggest cause of rework. Knowing this, we then had to determine the source of the dust. Although a large range of variables in the paint process could have been causing the contamination, by using Design of Experiments (DOE) and other advanced statistical methods, we found that the facility infrastructure and lack of discipline required to control paint room conditions was the primary contributor to the bottleneck. Our team developed a relatively inexpensive solution: a more efficient layout and process for the existing paint room and production facility. We also designed and implemented a future state facility change to ensure continued success of the new process.
By locating and managing the true cause of the bottleneck, the company was able to boost production by as much as 40 percent—allowing them to keep pace with demand and increase revenue.
The home furnishings company’s experience is a perfect example of why a rigorous and disciplined approach is needed to resolve production bottlenecks. Such an approach typically incorporates the DMAIC Process:
- Define: As mentioned earlier, a company generally knows where the bottleneck is: It’s the slowest activity delaying the rest of the process. However, pinpointing the reason why that particular activity is slow is crucial, and requires more than a casual look. Two powerful tools are especially useful in helping a company identify areas that merit deeper investigation. One tool is a Value Stream Map, which illustrates the entire activity or process, including cycle time, current steps, delays, information flows, and defects. Another is a Spaghetti Diagram, which helps pinpoint wasted movements that are adding unnecessary time to a process.
- Measure: To be able to improve a process, it is essential that a company understands where it’s starting from. Therefore, it must collect a wide range of process performance data to establish a current baseline. Ultimately, this baseline will be compared to performance metrics gathered after the project is complete in order to objectively determine whether significant improvement has been made.
- Analyze: Getting beneath the surface and uncovering what’s really going on generally requires next-level assessment tools such as the “5 Why” Analysis and a Fishbone Diagram, which help uncover cause-and-effect relationships. In some instances, use of these tools may reveal that a bottleneck has multiple causes, in which case a company must then determine how it wants to address them. A Pareto Analysis is helpful here, as it enables a company to prioritize the necessary changes based on which will be most successful in eliminating or reducing the bottleneck.
- Improve: Once a company knows which root cause to attack, it can then design and implement a solution. Typically, a solution will involve either Lean Management, Six Sigma Principles, or many times a combination of both. A lean solution is one that primarily targets… To read the complete article, please download the file by clicking the link in the right column.