We all know my affinity for MSA but it wouldn’t be fair if we didn’t talk about the measurements for a bit. Six Sigma is built on measurements and the corner stone of effectiveness is to have measurements that are appropriate. So let’s dig in and figure out what defines appropriate measures.
What makes it appropriate?
There are four key areas to consider when you are trying to determine if your metrics are appropriate:
- Is it sufficient?-When you consider this you will need to look at how available the metric is. Ask yourself if you can readily gather the data. If you have to collect it and the collection times require more energy and resources than you can give, it may be time to rethink this metric.
- Is it relevant?-What will this metric tell you? Does it help you understand or identify your problems? If it doesn’t then maybe you need to take a step back and figure out what you need your metric tell you.
- Is it representative?-When you are looking at this metric, you should see a balanced representation of the people and the steps involved in your process. If you can’t see these things, take another look at your goals. Are you measuring the right things?
- Is it contextual?-When this information is put together with all of the other information you collect, do you see the big picture? In other words is the data painting a picture that makes sense to your and the people involved?
So MSA like everything else in Six Sigma is a tool and the thing that we need to remember is that for it to be effective, we have to make sure we are using it appropriately. Check your systems and let me know how they are working. If they aren’t working, give us a call.
I am always an advocate of finding the right tool for your specific project, so I propose that you get to know MSA. It’s a great foundational tool and a great way to start building in the practice of good measurement within your organization. There are a few things you need to know when looking at your measurement system, let’s start with these.
What is a measurement system?
However your organization measures data, in Six Sigma we define your measurement system as ‘your complete process used to measure data’. The thing to know about measurement systems is the more moving parts you have, the more potential sources of errors you have.
What effects measurements?
Measurements are effected by a variety of factors, but some of the usual suspects are:
Accuracy-The numerical difference between what you think and what actually is.
Linearity-The change in the operating system of your measuring system. Think about when you have a different operating system on your laptop. Screens are viewed and you may have some errors. Same principal.
Stability-Something about your measurement system is inconsistent. It may be the way you intake data or the way your process it, but something is not consistent.
Precision-This is all about how much variation occurs in whatever it is you are measuring.
What are the red flags?
If your measurement system give you a reason to pause before you do anything, take a look at the repeatability and reproducibility of your measurement system. When you are looking for repeatability, you are looking for the variation that occurs when you measure the same piece of data using the same measurement method. For repeatability you are looking for the variation that occurs when different people measure the same thing using the same methods. To be fair there will always be some variation when multiple people are involved, but you want to get your measurement system as close to no variation as possible.
In creating your ideal situation, you may have to critical eye on your measurement system. It’s hard, but it is worth it. We will pick up on this subject next week and continue to fine tune your measurement systems!
In Six Sigma we are always collecting data, generally we are collecting data to address a current problem in our operations or services. The wonderful thing about Six Sigma is that we are also able to collect passive data. The usefulness of passive data is that it provides us with the ability to identify patterns, the catch to visualizing these patterns is in selecting the right graph to view the data.
Why use a graph?
The first benefit that comes to mind is the ability to see the error trends from a visual perspective. The other reasons graphs are a great tool are:
- Alongside identifying trends, they also help you see potential variable relationships. When you have a situation that could have multiple culprits, a graph can help you see which ones are a real potential.
- They can help you identify the risks that your customers will determine critical. This move allows your customer to be proactive instead of reactive, a much more desirable trait.
- It allows you to systematically dismiss variables and determine which one’s control other ones.
- It shows you the results of the passive data you’ve collected.
Where do I get the information for a graph?
Data is everywhere right? Yes and No. Your graph is only as good as your data, so we don’t want questionable data. The integrity of your data will be defined by your individual organization, but if you stick to these three questions you should be fine:
- What do you need the data to tell you?
- How often do you need to collect it?
- How do you need to collect it?
Next week we will get into the types of graphs and what times of data are appropriate for them. Until then happy hunting!
In any lean project there are a ton of buzzwords, but the one thing that is a universal truth in all lean initiative is that for any tool used to be successful it must be understood. In today’s blog we are going to talk about a Gemba walk and why it works.
What is it?
A Gemba walk is literally seeing where the work happens and the value of work. The reason for the walk can be varied but its importance is to illustrate the process to the people who will be responsible for improving it. I like Gemba because it takes 6Sigma out of theory and metrics and illustrates it in a tangible way that makes sense to the people using it.
What do I do?
This is by no means a comprehensive checklist, but it is a place to start when you are planning your Gemba walk. I provided a simple but comprehensive checklist to create your Gemba walk below.
- Identify the processes (internal/external) that the customer pays for and has an expected output.
- Identify who understands the process- What you are looking for here is not the person/division/team responsible for the process, but the person who designed the process and understands why it operates the way it does. This person should understand the performance gap analysis and have a plan to correct the gap (or at least the beginning of an idea).This step is hard for a lot of people because the knowledge master generally isn’t the person with the official responsibility, but it is critical that you get this step right.
- Focus on the steps of the process that add value, show standardization or show how the work is distributed.
- Know the expected outputs-Are they gaps? Are you asking why? Are you assigning blame? (If are, you shouldn’t be.)
- Identify the areas of the process that are going well, what is making that success happen?
- Now that you know what is working and what is not, create your checklist based on this information.
- Remember to steer clear of the 3M’s and educated your process leaders on them. Muda-Waste, Mura-process variation not caused by the customer, and Muri-overburden on facility, people and equipment caused by Mura and Muda.
This is pretty comprehensive checklist, but as with all my posts this is just to introduce you to the Gemba Walk tool. Consulting with your belt will give you the most useful questions and sources of information in your walk. Done correctly a Gemba walk jumpstart rapid improvement events, done incorrectly they can derail an entire initiative. What will you value today?