Process capability cp cpk study with excel template. Apr 30, 2001 converting defect rate to capability index. If you have a pchart to establish process control, the best estimate for capability is 1pbar converted to %. The software and its documentation is commercial computer software developed at private expense and is provided with restricted rights to the united states government. Version 1 of jmp went into production in october 1989. You can quickly determine which variables require attention, and see immediately what improvement strategy is required in each case retargeting, reducing variation, or both. The software at the heart of your quality program should incorporate a wide range. Managers, engineers, executives and supervisors who will use jmp software to perform process capability study and spc implementation.
This is the same as defining capability for continuous data cp and cpk. Jmp is the tool of choice for scientists, engineers and other data explorers in almost every industry and government sector. Jmp pro is the advanced analytics version of jmp statistical discovery software from sas. The process capability for a stable process, typically defined as usllsl 6 x standard deviation. Six sigma black beltqueens medical center honolulu, hi, usa. It is designed for users to investigate data to learn something unexpected, as opposed to confirming a hypothesis. Can anyone suggest freewareopensource statistics software to. This sticks out because, while as a rule everything in jmp is very visual and presentable, the cpk graph is a singlelineongreybackground drawing. Emphasis will be given on the correction of the common misconceptions through visual demonstrations using sas jmp s jsl interactive graphics. These are used to compute short and longterm capability indices.
In this video, i explain the concepts of process capability and process capability index. How to calculate cp and cpk learn to calculate process. A control chart is a graphical and analytic tool for monitoring process variation. It has since been significantly rewritten and made available for the windows operating system. Capability indices such as cp, cpk, pp, ppk are very popular.
John sall, sas cofounder and executive vice president, is credited for developing the jmp software and remains as its chief architect. Maintenance weekenderanheuserbusch fort collins, co, usa. It shows how closely a process is able to produce the output to its overall specifications. Some other topics will be included as well like discussions on spc, six sigma, and lean concepts.
Highly recommend to taking the time to master jmp statistical software if there is a real interest in having the best statistical software for your personal or company use. The larger the index, the less likely it is that any item. For software releases that are not yet generally available, the fixed release is. Statgraphics general statistics package to include cloud computing and six sigma for use in business development, process improvement, data visualization and statistical analysis, design of experiment, point processes, geospatial analysis. Short and long term capability indices for six sigma dummies. To complete the calculations, a set of data is required, usually generated by a control chart. The process capability analysis statlet compares the distribution of a set of n observations to one or twosided specification limits. The following programs are available for download on personal devices by rowan university students and employees, unless otherwise noted. You can use control chart builder to create control charts of your process data. Most software ive used will calculate short term capability cpk and long term ppk.
Aug 30, 2017 when the notation ppk is used in statistical software packages like sas jmp and minitab it is always based on the total variation. For example, if i am given values for cp and cpk the underlying process shift is not necessarily obvious. Short term cpk and long term ppk capability in jmp. Sep 03, 2018 so now we can confidently talk about process capability in terms of the indices cp and cpk. Software information resources and technology rowan. Jmp software is partly focused on exploratory data analysis and visualization. This capabilities index provides brief summaries of analytic features in jmp software. The capability maturity model was originally developed as a tool for objectively assessing the ability of government contractors processes to implement a contracted software project.
The capability index plot shows ppk values for all variables that you entered as y, process. First, this book provides considerable training in the basic functions of jmp 15. The division of information technology currently distributes software and licenses for jmp version 11, 12, and 14. Process capability analysis and process analytical technology. The question is that i heard that there is a new procability capability index not cpk. Cpk is a short term process index that numerically describes the within subgroup or potential capability ppk is long term indicator of a process assuming it was analyzed and stays in control. Cpk is used to estimate how close you are to a given targe. Minitab, jmp, and matlab software provide support for process capability analysis. Because of this, its important to understand and quantify the sources of variation within a process. Let we understand this concept with the help of a simple example. Jsl stands for jmps scipting language, and is a utility that can extend jmp softwares capability. Calculating capability indices with one specification data.
This promotes senselessly tight control limits, especially in cases where slight shifts in the process mean occur when an input parameter has been changed such as raw materials, setups, lots and so forth. Process capability index cpk is the measure of process capability. Make sense when the target is the lower tolerance limit. Emphasis will be given on the correction of the common misconceptions through visual demonstrations using sasjmps jsl interactive graphics. Conventions for mapping jmp attributes to sas extended attributes. The terms c pk and p pk are often confused, so that when quality or process engineers refer to the c pk index, they often actually intend to mean p pk indices. Interpreting c p, c pk c pk is an index a simple number which measures how close a process is running to its specification limits, relative to the natural variability of the process. Production control team member entrylevellockheed martin corporation greenville, sc, usa. Dont blindly follow the recommendations of any software, even one as righteous as jmp. Quality engineering, reliability and six sigma jmp. Sep 11, 2009 jsl stands for jmp s scipting language, and is a utility that can extend jmp software s capability. See attached for some tips on calculating capability for unilateral tolerance. Mcmurry written specifically as material for chance courses july 24, 1992 this guide is intended to help you begin to use jmp, a basic statistics package, and apprise you of its general capabilities and limitations.
The presentation begins with a short introduction to process capability. Jmp pronounced jump is a suite of computer programs for statistical analysis developed by the jmp business unit of sas institute. Shortterm capability index cp determining the width between the two rigid specification limits is easy. There are other nonparametric capability analysis methods available. This manual assumes that you are familiar with operating a macintosh computer. Jmp is used in applications such as six sigma, quality control. Spc practitioners applying control charts to processes with high cpk 2. To my knowledge, jmp only calculates the capability index that uses the sample standard deviation, and gives the user the option of including the label ppk. If you fit a nonnormal distribution, the fitted distribution name appears in the plot as a parenthetical suffix to the variable name.
This paper addresses process capability and the new functionality the process capability platform brings to jmp. When the notation ppk is used in statistical software packages like sas jmp and minitab it is always based on the total variation. The use of a multivariate normal distribution for estimating. Its an option along with zscore and ppm when describing process baseline measurement in the measure phase or in the control phase. Each page in the index is adapted from jmp documentation and includes a summary and screenshot of the feature described. Figure 3 contains a lot of information useful for a pca assessment. That is cpmtaguchi process cability index which is from a. The current license runs from july 1 through june 30, youll need to update the license. In simple words, it measures producers capability to produce a product within customers tolerance range. Analyze quality and process control chart builder, analyze quality and process control chart ir. Process capability index cpk is a statistical tool, to measure the ability of a process to produce output within customers specification limits. Jmp statistical discovery software from sas vs rstudio. Please note that the indices in point 1 above, in the form of capability. Online pricing and ordering are available for windows and macintosh customers who meet certain criteria.
Jmp 12 includes a new platform for examining the performance of a process in relationship to the specification limits. Statistical software are specialized computer programs for analysis in statistics and econometrics. Apr 20, 2019 process capability is a statistical measurement of a processs ability to manufacture parts within the specification consistently. Capability for one sided specification the quality forum online. The width of the specification window can be identified simply by rearranging the above formula. The histogram and fitted normal curves provide an informal way to quickly check for. How can i calculate capability index ppk with a usl set at. How to pick the correct distribution for a capability index plot. Introduction a process capability index is a numerical summary that compares the behavior of a product. Properties associated with control charts and capability. It compares the width of a twosided specification to the effective shortterm width of the process.
So now we can confidently talk about process capability in terms of the indices cp and cpk. From within the distribution output, select capability analysis from the columns red triangle menu. Scripting guide sas customer support site sas support. Jmp is available at no charge to isu faculty, staff and students for the mac and windows platforms. Jmp is a fullfeatured, highly interactive, visual, and comprehensive package. Remember, if you are automotive, the aiag ppap 4th edition specifies that you cannot use cp, cpk, pp and ppk with unilateral tolerances. Jmp, a business unit of sas sas campus drive cary, nc 275 the real voyage of discovery consists not in seeking new landscapes, but in having new eyes. Complete the following steps to interpret a normal capability analysis. Launch jmp and locate the file to reactivate your jmp software. Quality methods a process that is off target, too variable or out of control can result in delays, rework or defects, which in turn often lead to higher costs and unsatisfied customers. Im wondering how jmp users calculate the newer cpk index that uses the pooled standard deviation from a control chart. Interpret the key results for normal capability analysis. P pk is used to assess the longterm, overall variability, whereas c pk is the capability index for shortterm, potential variability.
Pronounced as jump, jmp is a tool for exploring data and interacting with it. Capability analysis is a set of calculations used to assess whether a system is statistically able to meet a set of specifications or requirements. Adjustment of p p for the effect of noncentered distribution. How does one calculate cpm taguchi process capability. Are you setting requirements for cpk while you should be. Exactly,i know the meaning of cpm and what the calculation is. However, my favorite part of jmp is the ability to rollup the data very easily the summary functions for rolling up cov studies is a piece of cake in jmp.
The capability index is the ratio of the specification width to process width. There are many functionalities that allow users to reorganize the data, customize the analysis of the data, and build really neat graphs to. If you are looking to install software on a universitymanaged computer, please submit a request. Navigation functions let you easily move forward or backwards in the index. Minitab is generalpurpose statistical software package that provides a nice graphical summary of process capability, figure 3. Jmp is statistical software created by sas, a leading company in business analytics software and services.
It would be great if the software could provide distribution identification analyses in a manner similar to those of jmp the exploratory software package associated with sas. Jm p is not a part of the sas system, though portions of jmp were adapted from routines in the sas syst em, particularly for linear algebra and probability calculations. Process capability analysis ii accendo reliability. Implementing and maintaining spc program important factors to consider and steps for effective implementation. Each variable name appears on the horizontal axis and the ppk values appear on the vertical axis. Calculating capability indices with one specification. The capability platform allows you to compare the capability of numerous variables in one plot. Jmp or minitab six sigma isixsigma forums old forums general jmp or minitab this topic has 1 reply, 2 voices, and was last updated 14 years, 1 month ago by darth. It only works if both sides are bounded, such as roundness. Jmp can handle any size of a data set and does a great job in keeping all of your work organized. Properties that control how columns are used in platforms.
The cpk process capability module output is shockingly poor in jmp. Sep 25, 2016 in this video, i explain the concepts of process capability and process capability index. From within the distribution output, select capability analysis from the columns. We will use process capability in jmp to generate a capability analysis. Distribution xy b yt fi tabulate text explorer covers how to perform bivariate, oneway anova, and contingency analyses through analyze fit y by x. Process capability cp, cpk and process performance pp.
Creating a capability analysis in jmp using your specification limits. Key output includes the histogram, normal curves, and capability indices. The process capability index for a stable process, typically defined as. The capability to script and automate so many statistical approaches is a powerful tool that allows for users to really delve into repeated datasets.
If you have questions about online ordering or pricing, or if you require a license that allows. From what i understand, jmp only provides cpk, but gives different options for the calculation. Chapter 1 learn about jmp 23 quality and process methods jmp documentation basic analysis perform basic analysis using this document. Capability analyses can be performed several ways in jmp. Understanding process capability indices stefan steiner, bovas abraham and jock mackay institute for improvement of quality and productivity department of statistics and actuarial science university of waterloo waterloo, ontario n2l 3g1 1. Usl upper specification limit, lsl lower specification limit. This macro calculates capability indices cnpk using the empirical percentile method as described in the reference d. Capability indices for nonnormal data, quality engineering, 12 4, 489495. With great software and a curious mind, anything is possible.
Your process should be stable and the original or transformed process data should follow a normal distribution. It is a statistical tool to measure the variability of the process and it is a part of statistical process control. Jmp pro provides all the superior visual data access and manipulation, interactivity, comprehensive analyses, and extensible capabilities that are the hallmarks of jmp, then adds modern predictive modeling, crossvalidation, exact measures of association, oneclick bootstrapping and model comparison features. Each page in the index is adapted from jmp documentation and includes. Interactive and visual, jmp reveals insights that raw tables of numbers or static graphs tend to hide. Please visit the jmp store to make your purchase thank you for your interest in jmp software. Jmp combines dynamic data visualization with powerful statistics, in memory and on the desktop. Ppk is an process capability index that assesses how close the process mean is from the specification limit. To save the limits and target back to the data table, choose save spec limits. Capability, accuracy and stability processes, machines, etc.
Credits jmp was conceived and started by john sall. Seven of the variables are fit with nonnormal distributions. Nov 22, 2017 this video describes the analysis of process capability for multivariate data, including estimation of multivariate capability indices. Capability for one sided specification the quality forum. My question is whether the short term calculation in jmp equates to the rbard2 formula that other software.
Food served at a restaurant should be between 38c and 49c when it is delivered to the customer. Ppk is therefore a measure of overall process capability, i. Total variability is used in the denominator instead of the short term. The model is based on the process maturity framework first described in ieee software and, later, in the 1989 book managing the software process by watts humphrey. Jmp is much more suited to taking a data set and starting from square 1 and exploring it through a range of analytics. The book assumes that you have the software at your school or office. Zupper usl mean estimated sigma zlower mean lsl estimated sigma estimated sigma average. Jmp pro provides superior visual data access and manipulation, interactive, comprehensive analyses and extensibility according to the vendor, these are the hallmarks of jmp, plus a many additional techniques. But it seems to me that this is convenient shorthand at the expense of transparency.
Yes, jmp does produce the process capability index, cpk. It was launched in 1989 to take advantage of the graphical user interface introduced by the macintosh. If possible, could you specify your answer on the above my questions. Version 15 jmp, a business unit of sas sas campus drive cary, nc 275 15. The following formula for cpk is easily found in most statistics books, as well as in software products such as sqcpack. Points have been labeled using the label overall sigma points option that is available in the capability index plot red triangle menu. The simplest capability index for six sigma is called cp or short term capability index. If you write a lot of macros in minitab, there could be a learning curve switching over to jmp. The issues with capability indices will be discussed in a future article. Jmp and jmp pro product page on the support site has the latest news, samples, downloads, support information, training, and documentation. Jsl stands for jmp s scipting language, and is a utility that can extend jmp software s capability. If the process is in control and the distribution is well within the specification limits then the difference between the upper.
1118 1355 1355 379 232 1562 645 1408 1214 47 1516 303 1438 116 810 1035 603 1230 740 8 1230 1475 170 616 1412 566 412 987 291 650 663 12 1219 510 504 634