Key Points

• Cmk is a capability index used in production.
• They are short-term indices, rather than something longer in scope.
• Cmk is a useful way of understanding how a machine is performing.

Many people sometimes confuse Cmk and Cpk. An easy way to distinguish the two is to remember the ‘M’ in Cmk lets you know that it is the Machine Capability Index and the ‘P’ in Cpk lets you know that it is the Process Capability Index.

Overview: What Is a Machine Capability Index?

It is an index that is pulled from the observations of an uninterrupted production run. The machine capability index is a short-term index and is used as a measurement tool for determining how effective machine improvement efforts are.

4 Benefits of a Machine Capability Index

There are several benefits of utilizing a machine capability index. Let’s take you through a few of them:

1. Authentication

It verifies a new machine.

2. Helps track improvements

Using a machine capability index verifies the efficiency of machine improvements to determine if they sufficiently benefit processes.

3. Constant verification

With a machine capability index, existing machines receive continual verification to ensure everything is on the right track.

4. Forecasting

A machine capability serves as a valuable tool for forecasting trends and as an indicator.

Why It Works

Machine capability is something you definitely should be paying attention to. However, the way it works effectively in your production is by providing empirical data on how a machine is performing.

There is no shortage of machines used throughout any production. Whether you’re using new installations or relying on tried and proven machines, having hard data on hand is a great way to gauge how they’re faring.

Why Is a Machine Capability Index Important to Understand?

There are several reasons to understand a machine capability index:

Added Confidence

A Cmk study is meant to minimize variation, so running a new machine through the index can assure additional confidence that the new machine can hold up.

It Paves the Way for a Long-term Index

Before you can determine the long-term effectiveness of a machine, you need to first know how it does on an initial run. A machine capability index is a good key for how the initial run will go and gives you insight before running a long-term index.

Having a Thorough Knowledge of Capability Indices Can Be Crucial

Capability indices do more than just help you meet the requirements. They focus on continued improvement and can lead to the constant betterment of your machines and processes.

An Industry Example of a Machine Capability Index:

An operations manager is asked to approve a new machine in a shop that will cut back on costs. To determine if the machine is going to make the cut, a machine capability index is utilized. The value of the index is found to be 2.0 and the new machine is accepted as part of production.

Best Practices

Here are some practices to keep in mind when it comes to the machine capability index:

1. Prepare Accordingly

For a machine capability index to be reliable, the capability study needs to be adequately planned, sufficiently performed, and thoroughly evaluated.

2. Remember It Is a Short-term Index

A machine capability index is typically geared towards new machines and has limits to what it can tell you. It should not be used as a long-term index of how things are going.

3. If You Already Know Other Capability Indices, Cmk Is Fairly Simple.

If you already know the two most common capability indices, Cpk and Ppk, Cmk follows the same general formula and should be easy to add to your knowledge base.

Other Useful Tools and Concepts

Looking for some other tools of the trade? Why not take a look at Six Sigma? Six Sigma isn’t just an approach or methodology, but rather a means of transforming your organization. With a data-driven approach to quality, you can see massive returns.

Additionally, understanding the coefficient of variation can be useful when leaning on measurements like Cmk. Seeing just how far measurements are straying from a standard deviation can help you drill down and improve processes as needed.

Implementing a Machine Capability Index

Now that you have had an introduction to the benefits of running a machine capability index, you know a tool in your belt for determining the initial improvement the new machine adds to your business processes.