Commonly Used Six Sigma Metrics

Six Sigma Technique brings about improvement to any business using data. However, to achieve this improvement, we should derive Six Sigma Metrics like RTY, PPM, DPMO and DPU from the data. The reason is that these metrics help any business to decide on the processes to follow. These metrics are the standard or system of measurement. They aid with capturing the knowledge that is then translated into chances for growth and improvement. 

Six Sigma Metrics – What Are They?

As mentioned earlier, Six Sigma Metrics are common measurements. Their purpose is to help users like you track the quality of the process. These metrics originate from the manufacturing industry. Also, other businesses use them in combination with lean production processes. They do this for improving the efficiency of the processes they follow. For instance, one technique to evaluate the quality of any process is to evaluate the rate of the defect. It is nothing but the number of defective units in the overall production run.

Usage of Six Sigma Metrics:

Nowadays, many businesses rely on the commonly used Six Sigma Metrics. However, you will be interested in knowing how these metrics are used. Here are some of the common ways in which businesses use these metrics these days:

To Improve Customer Satisfaction:

Any process that provides a very good experience to customers often will have low cycle times and a low rate of defects. Even, they carry other features like ease of use and attractiveness to the eyes.

Ranking:

Businesses can use Six Sigma Metrics for ranking their processes. When they rank, they can identify the processes that need improvement and can work on them with priority.

Benchmarking:

Organizations can rely on Six Sigma metrics for benchmarking the efficiency of processes they follow. In turn, they can understand whether the processes they follow are in line with the processes that the other businesses in their industry follow.

For Improving Efficiency:

Six Sigma metrics can be of great help when it comes to improving process efficiency. Efficiency can be achieved in any process when wastes are brought down, cycle time is reduced and the rate of defects is brought down.

Types of Six Sigma Metrics:

Before gaining knowledge on the most commonly used Six Sigma metrics, it is better to know the types of these metrics. 

When you take the case of any measures taken by any business to improve processes, the key goal will be to ensure a better, cheaper and quicker process. Thanks to Six Sigma Metrics! They help any business to achieve these things in any process. If you make any process better by reducing or nullifying defects, you can complete the process quickly. When the process turns quicker, you should be able to get rid of defects as quickly as possible. The same rule applies to affordability as well. When a process is made better and quicker, you are making it cheaper. This is why Six Sigma Metrics are brought under the following three categories:

• The metric that will make the process cheaper is “cost of poor quality”.
• For ensuring the quickness of the process – Cycle Time is the metric to follow.
• For process betterment, the metrics are Defects per million opportunities, defects per unit and rolled throughput yield.

Here are the key types of Six Sigma Metrics:

The Primary Six Sigma Metrics:

Primary Six Sigma metrics are quantified measures of the primary issue or defect in a project. The primary metric can function as an indicator of the success of a project. When talking about the primary metric for Six Sigma, Six Sigma carries some specific characteristics. In other words, it aims at helping businesses make cost-effective products with quality and on-time delivery to customers. The main goal of primary metrics is to ensure customer satisfaction.

• A project will have only one primary metric
• The primary metric of any project should be linked to the primary business measure. In other words, the primary metric of any project should be aligned with that of the overall business objective.
• The primary metric should be easy to measure.
• It should be possible to explain it with an equation
• It should be linked to the problem statement.

Secondary Six Sigma Metrics:

The goal of secondary metrics is to evaluate the possible changes that might occur as a result of changes made to the basic metric. In other words, the secondary metrics of any project will evaluate the positive and negative outcomes of any changes made to the process associated with a project.  

A single project can have many secondary metrics. Examples of secondary Six Sigma metrics include rework time, lead hours and cycle time to name a few. To ensure project success, you should measure both primary and secondary metrics frequently. Apart from measuring, they should be updated monthly, weekly or even daily during the life cycle of the project. 

Key Six Sigma Metrics:

Now, you know that any Six Sigma metric will come under the category of either primary metrics or secondary metrics. Let us gain some understanding of some of the commonly used Six Sigma metrics:

1. Critical to Quality Metrics:

In the Six Sigma methodology, different methods are used for measuring operational and process performance. When it comes to evaluating the process performance, Yield is a classic method used. However, this measure can be supplemented with broader measures of performance like Rolled Throughput Yield and Throughput Yield. These measures are helpful with process comparisons. However, they make the details required for process improvement uncertain.

So, to get the complete details for process improvement, the classic Process Capability Index technique can be of great help. The reason is that this technique needs the associated use of statistical control chart. This chart is essential for verifying the stability of the process metric.

The control chart provides the analytical tool required for process improvement by spotting the difference between inherent variations that are built into a process and changes to a process. Understanding this difference is important for process improvement. The reason is that the response to special causes of variation is essentially different as compared to the response to inherent variation.

2. Defect Rate:

When businesses do not effectively produce units of a product, defects happen in the production process. It will be possible for you to arrive at the defect rate by dividing the number of defective items by the total number of units produced in a given lot or a particular period. For instance, let us consider that a manufacturing unit has produced 10,000 units of a particular product within two days. Out of these 10,000, five pieces are defective. Now, the defect rate is 5 divided by 10,000, which is equal to 0.05%. The actual value you will get when dividing 5 by 10,000 is 0.0005. For converting this value to a percentage, you will have to multiply it by 100. The result will be 0.05%.

3. Time Metric:

This metric will help an organization gauge the amount of time it takes for producing a product. Apart from evaluating the overall time, this metric will help with knowing the processing time versus process idle time. When it comes to time metric measures, different areas of time get into the picture. It can help with the evaluation of lead time for a process. It is nothing but the amount of time it takes for developing a product right from the beginning to the end from the point of view of customers.

This metric will also measure the time it takes for completing a process right from best to worst. It works by assigning a value to each process. In turn, it helps with identifying what processes are continually falling short or living up to business expectations. Another measure that this metric quantifies is the activity ratio, which is evaluated by dividing the processing time by the lead time. With this, it will be possible to identify the real-time it takes to make a product and ship it to customers.

4. Rolled Throughput Yield:

One of the commonly used Six Sigma metrics, this metric is shortly called RTY. Its purpose is to solve issues. It is the possibility that a process with more than a single step will be able to produce units that are free of defects. To arrive at RTY, you will have to first evaluate the yield for each step in the process. Then, you should multiply the yield of each step involved in a process to identify the RTY of the entire project.  

Conclusion:

These are just a few commonly used Six Sigma metrics as many other metrics are also used by organizations. It will not be easy to say which metric will suit your business. Some businesses also create their own Six Sigma metrics as against following the metrics that are already being used by an organization. This type of customization will help any business increase efficiency and improve product quality, which are key purposes of Six Sigma metrics. The examples of companies that have successfully reduced defects in the production will help with increasing your confidence level on these metrics. Simpliaxis offers comprehensive Six Sigma courses to help you master these metrics and drive your business success. Enroll today and start your journey towards operational excellence.