Definition of Black Noise:« Back to Glossary Index
Black noise, also known as special cause variation, is a type of variation that can occur in Lean Six Sigma. It is important to understand how to identify and eliminate black noise because it can lead to problems with a system’s efficiency, throughput, and quality.
Black noise is a non-random deviation from expected output. In other words, it is something that does not fit the pattern of what was supposed to happen; it is not a part of the process. Black noise is generally caused by human error or random events that occur outside of the normal parameters of a process, such as equipment failure or a change in environment. Whatever the cause, it is always assignable. The most effective way to eliminate black noise is through continuous improvement initiatives that are focused on eliminating waste within your organization’s processes.
Drawbacks to Black Noise
Black noise, or special cause variation, can have both benefits and drawbacks in the context of Lean Six Sigma. There is ultimately one main benefit to black noise: it enables businesses to understand and predict processes so that improvements can be made to them, which reduces waste and makes them more efficient in general.
There are drawbacks to consider, such as:
It’s not always easy to identify what’s causing it.
All possible causes of variation must be evaluated before work can begin on improving anything. This can take time and money that might be better spent elsewhere if there is no access to resources like data scientists or engineers who can help analyze things.
It can undermine the ability to make meaningful improvements in performance.
If you’re trying to figure out where your processes are leaking time and money, you need to be able to identify where those leaks are coming from. And if you have to spend time eliminating special causes of variation (such as holidays or other events that impact your process), then your analysis will be less accurate and meaningful.
It is a time-sensitive, non-random event.
Special cause variation means that you need to take action immediately, rather than waiting for the next batch of data from the process you’re trying to improve. The longer you wait to fix a problem with your process, the more likely it is that any improvement will be lost. And because it can be caused by many things, including human error and equipment malfunction, it is difficult to predict or anticipate.
Why is Black Noise Important to Understand?
Black noise is important to understand because it can help you identify the potential for variation that can impact your process. If you’re trying to improve a process, it’s important to know what factors affect that process and make it less efficient. Black noise is one type of variation that can impact your process, so understanding how it works will help you know how best to approach improving it.
An Industry Example of Black Noise
One of the best examples of black noise in practice is when a company uses it to improve their supply chain. This is because it’s easy for black noise to get lost in the background when there are many other factors that influence supply chains, but when you’re looking for ways to make your supply chain more efficient and reliable, it can be incredibly helpful to identify patterns that might not be immediately apparent.
A good example of this is when a company has a large number of warehouses spread out across different locations. In this case, it’s possible that each warehouse will have its own variation in how much product they receive from suppliers, which can cause problems with scheduling and inventory management. However, if the company could identify which warehouses had better relationships with their suppliers than others, then they could use that information to help them schedule orders more effectively and plan future expansions accordingly.
Best Practices When Thinking About Black Noise
The best practices to consider when analyzing black noise are:
Understand the root cause of black noise.
Black noise can be caused by many different factors, but it is important to understand what causes each variation so that you can determine what needs to be done to reduce it.
Use a control chart to identify black noise.
A control chart can help you quickly determine whether or not a process is stable, and if it’s not, you can use that information to determine how to make adjustments that will bring it back into stability.
Use a histogram or Pareto chart to identify black noise.
These charts show the distribution of values and can help you identify if there are any outliers that may be causing problems for your process.
Frequently Asked Questions (FAQ) About Black Noise
What is noise in a process?
Noise is anything that can cause variation in your process. This includes: External factors such as weather, location, or time of year. Internal factors such as changes in employee performance or equipment availability.
How do you know if your process has black noise?
- the range of values being produced by the process is very large;
- the variation occurs in all directions; and
- there are no clear patterns in the data.
How do you account for black noise during analysis?
To account for black noise, you need to find ways to remove it from your data set before performing any analysis on it. One way to do this is by using control charts or histograms that show how many times each value appears within a given range (e.g., from 0-10). In order to ensure that these charts are accurate, they should be based on samples taken throughout the entire range of possible values.
Mitigation vs Elimination
Black noise does have a negative connotation. However, if it can be better understood and managed, managers can use this knowledge to their advantage. If a manager understands the relationship between black noise and their processes, they can divert their efforts from trying to eliminate it to areas where problem solving and improvement will yield the most impact.