AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
Meaning of six sigma10/22/2023 Meeting your customers’ expectations and requirements is vital to your organization staying in business. If a manufacturing line had a Cp of 0.82, and a finance department had a Cp of 1.89, you could say that finance is doing a better job of meeting their customer’s requirements than is manufacturing. The Cp allows you to compare the performance of disparate functions since it is a generic measure of the process’ ability to meet specs. Can be used to compare different processes But, as it is in most cases, if the process is shifted off-center, then the Cpk will account for that shift. If the process is centered within the specs, you would use the calculation of Cp to assess the potential of your process capability. Can account for a process centered within the specs To compute your Cp value, you only need to know the standard deviation of your data and the specs that you want to test against. 3 benefits of CpĬp is a simple and useful metric for comparing your process with your internal or external specifications, targets, expectations, or any other desired outcome for your process. That’s when we need to use the Cpk to assess the process capability. Interestingly, if the process mean is off-center, the Cp will still be the same since the Cp does not consider the location of the process. More often than not, the process mean ( x-bar ) will not be centered within the specs. If the value is less than 1, it means the width of the process distribution is wider than the specs, and items will be outside the specs.īut, all of this assumes that the process is centered within the specs - this is rarely the situation.A value greater than 1 would mean the specs are wider than the distribution of the process, so we are comfortably within spec.A value of 1 would mean the width of the distribution is equal to the width of the specifications, or specs.The standard deviation that is used is called a “pooled standard deviation” or “within variation.”Ĭp can take on values equal to 1, greater than 1, or less than 1. We are assuming that the sample distribution is normally distributed, and its width is calculated by adding and subtracting 3 standard deviations on either side of the sample data mean. You can say this as Cp is equal to the customer’s upper specification limit minus the lower specification limit divided by 6 standard deviations. If there is only a one-sided spec, then Cp cannot be calculated. It represents the best the process capability can be for the specs and process distribution. Ĭp, or capability potential, is a measure of the potential capability with the assumption that the distribution of the sample process data is normally distributed and centered within the customer’s upper specification limit and lower specification limit. The goal of process capability is to come up with a quantified measure that informs you as to whether you are meeting your customer expectations or not - as well as a relative value of how well you are meeting or how badly you are missing.īesides Cp, or capability potential, there are a number of other process capability metrics. Process capability is the quantifiable comparison of the Voice of the Customer (specs, requirements or expectations of your customer) and the Voice of the Process ( control limits ). We will explore its application, benefits and provide some tips and best practices so that you can begin assessing how well your process is doing when measured against the requirements specified by your customer. This article will explain how Cp is calculated and interpreted. Cp is a common measure used in process capability analysis, which allows you to know how well your process is meeting your customers’ expectations and specifications.
0 Comments
Read More
Leave a Reply. |