Process capability analysis ii accendo reliability. Capability analysis is a set of calculations used to assess whether a system is statistically able to meet a set of specifications or requirements. This macro calculates capability indices cnpk using the empirical percentile method as described in the reference d. Please visit the jmp store to make your purchase thank you for your interest in jmp software. Jmp is available at no charge to isu faculty, staff and students for the mac and windows platforms. For example, if i am given values for cp and cpk the underlying process shift is not necessarily obvious. Each variable name appears on the horizontal axis and the ppk values appear on the vertical axis. If you write a lot of macros in minitab, there could be a learning curve switching over to jmp. 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. Pronounced as jump, jmp is a tool for exploring data and interacting with it. If you are looking to install software on a universitymanaged computer, please submit a request.
Jsl stands for jmp s scipting language, and is a utility that can extend jmp software s capability. 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. Your process should be stable and the original or transformed process data should follow a normal distribution. Capability for one sided specification the quality forum. To save the limits and target back to the data table, choose save spec limits. First, this book provides considerable training in the basic functions of jmp 15. Are you setting requirements for cpk while you should be. Adjustment of p p for the effect of noncentered distribution. Can anyone suggest freewareopensource statistics software 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. From within the distribution output, select capability analysis from the columns. This is the same as defining capability for continuous data cp and cpk. John sall, sas cofounder and executive vice president, is credited for developing the jmp software and remains as its chief architect. With great software and a curious mind, anything is possible.
The simplest capability index for six sigma is called cp or short term capability index. Sep 25, 2016 in this video, i explain the concepts of process capability and process capability index. If you have questions about online ordering or pricing, or if you require a license that allows. My question is whether the short term calculation in jmp equates to the rbard2 formula that other software. Please note that the indices in point 1 above, in the form of capability. Shortterm capability index cp determining the width between the two rigid specification limits is easy. Jmp is a fullfeatured, highly interactive, visual, and comprehensive package. The use of a multivariate normal distribution for estimating. This sticks out because, while as a rule everything in jmp is very visual and presentable, the cpk graph is a singlelineongreybackground drawing. Process capability cp, cpk and process performance pp. 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. 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. 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.
Zupper usl mean estimated sigma zlower mean lsl estimated sigma estimated sigma average. Jmp and jmp pro product page on the support site has the latest news, samples, downloads, support information, training, and documentation. It is a statistical tool to measure the variability of the process and it is a part of statistical process control. 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 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. Process capability index cpk is the measure of process capability. The width of the specification window can be identified simply by rearranging the above formula. The division of information technology currently distributes software and licenses for jmp version 11, 12, and 14. 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. Jmp is statistical software created by sas, a leading company in business analytics software and services. Ppk is an process capability index that assesses how close the process mean is from the specification limit. 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.
Sep 11, 2009 jsl stands for jmp s scipting language, and is a utility that can extend jmp software s capability. Im wondering how jmp users calculate the newer cpk index that uses the pooled standard deviation from a control chart. Creating a capability analysis in jmp using your specification limits. Jmp is much more suited to taking a data set and starting from square 1 and exploring it through a range of analytics. Process capability analysis and process analytical technology. Jmp pronounced jump is a suite of computer programs for statistical analysis developed by the jmp business unit of sas institute. This manual assumes that you are familiar with operating a macintosh computer. If you have a pchart to establish process control, the best estimate for capability is 1pbar converted to %. You can use control chart builder to create control charts of your process data.
Process capability index cpk is a statistical tool, to measure the ability of a process to produce output within customers specification limits. Jsl stands for jmps scipting language, and is a utility that can extend jmp softwares capability. Total variability is used in the denominator instead of the short term. The following formula for cpk is easily found in most statistics books, as well as in software products such as sqcpack. Sep 03, 2018 so now we can confidently talk about process capability in terms of the indices cp and cpk. Apr 20, 2019 process capability is a statistical measurement of a processs ability to manufacture parts within the specification consistently. Conventions for mapping jmp attributes to sas extended attributes. Jmp pro is the advanced analytics version of jmp statistical discovery software from sas. Minitab, jmp, and matlab software provide support for process capability analysis. Exactly,i know the meaning of cpm and what the calculation is. It compares the width of a twosided specification to the effective shortterm width of the process. To complete the calculations, a set of data is required, usually generated by a control chart. It is designed for users to investigate data to learn something unexpected, as opposed to confirming a hypothesis.
It was launched in 1989 to take advantage of the graphical user interface introduced by the macintosh. Properties that control how columns are used in platforms. Navigation functions let you easily move forward or backwards in the index. Version 15 jmp, a business unit of sas sas campus drive cary, nc 275 15. It has since been significantly rewritten and made available for the windows operating system. When the notation ppk is used in statistical software packages like sas jmp and minitab it is always based on the total variation. Software information resources and technology rowan. A control chart is a graphical and analytic tool for monitoring process variation. Production control team member entrylevellockheed martin corporation greenville, sc, usa.
Ppk is therefore a measure of overall process capability, i. Jmp combines dynamic data visualization with powerful statistics, in memory and on the desktop. How does one calculate cpm taguchi process capability. Online pricing and ordering are available for windows and macintosh customers who meet certain criteria. The process capability for a stable process, typically defined as usllsl 6 x standard deviation. Scripting guide sas customer support site sas support. Points have been labeled using the label overall sigma points option that is available in the capability index plot red triangle menu.
But it seems to me that this is convenient shorthand at the expense of transparency. Credits jmp was conceived and started by john sall. Chapter 1 learn about jmp 23 quality and process methods jmp documentation basic analysis perform basic analysis using this document. Interactive and visual, jmp reveals insights that raw tables of numbers or static graphs tend to hide. 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. Capability indices such as cp, cpk, pp, ppk are very popular. Apr 30, 2001 converting defect rate to capability index. 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.
You can quickly determine which variables require attention, and see immediately what improvement strategy is required in each case retargeting, reducing variation, or both. Each page in the index is adapted from jmp documentation and includes. 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. Capability for one sided specification the quality forum online. Spc practitioners applying control charts to processes with high cpk 2. The larger the index, the less likely it is that any item. Maintenance weekenderanheuserbusch fort collins, co, usa. For software releases that are not yet generally available, the fixed release is. That is cpmtaguchi process cability index which is from a. Capability, accuracy and stability processes, machines, etc. Jmp can handle any size of a data set and does a great job in keeping all of your work organized. Short term cpk and long term ppk capability in jmp. The process capability analysis statlet compares the distribution of a set of n observations to one or twosided specification limits. How to pick the correct distribution for a capability index plot.
How can i calculate capability index ppk with a usl set at. Minitab is generalpurpose statistical software package that provides a nice graphical summary of process capability, figure 3. Nov 22, 2017 this video describes the analysis of process capability for multivariate data, including estimation of multivariate capability indices. The cpk process capability module output is shockingly poor in jmp. Because of this, its important to understand and quantify the sources of variation within a process. There are many functionalities that allow users to reorganize the data, customize the analysis of the data, and build really neat graphs to. Make sense when the target is the lower tolerance limit. How to calculate cp and cpk learn to calculate process. The current license runs from july 1 through june 30, youll need to update the license.
The software at the heart of your quality program should incorporate a wide range. Each page in the index is adapted from jmp documentation and includes a summary and screenshot of the feature described. In this video, i explain the concepts of process capability and process capability index. There are other nonparametric capability analysis methods available. If you fit a nonnormal distribution, the fitted distribution name appears in the plot as a parenthetical suffix to the variable name.
Managers, engineers, executives and supervisors who will use jmp software to perform process capability study and spc implementation. The question is that i heard that there is a new procability capability index not cpk. The histogram and fitted normal curves provide an informal way to quickly check for. Its an option along with zscore and ppm when describing process baseline measurement in the measure phase or in the control phase. In simple words, it measures producers capability to produce a product within customers tolerance range. Yes, jmp does produce the process capability index, cpk. From within the distribution output, select capability analysis from the columns red triangle menu. Jmp is the tool of choice for scientists, engineers and other data explorers in almost every industry and government sector. Launch jmp and locate the file to reactivate your jmp software.
This capabilities index provides brief summaries of analytic features in jmp software. Six sigma black beltqueens medical center honolulu, hi, usa. Figure 3 contains a lot of information useful for a pca assessment. Emphasis will be given on the correction of the common misconceptions through visual demonstrations using sasjmps jsl interactive graphics. Complete the following steps to interpret a normal capability analysis. Seven of the variables are fit with nonnormal distributions. Food served at a restaurant should be between 38c and 49c when it is delivered to the customer. Capability indices for nonnormal data, quality engineering, 12 4, 489495. Calculating capability indices with one specification. Remember, if you are automotive, the aiag ppap 4th edition specifies that you cannot use cp, cpk, pp and ppk with unilateral tolerances. Analyze quality and process control chart builder, analyze quality and process control chart ir. Jmp statistical discovery software from sas vs rstudio. Dont blindly follow the recommendations of any software, even one as righteous as jmp.
The following programs are available for download on personal devices by rowan university students and employees, unless otherwise noted. Short and long term capability indices for six sigma dummies. Process capability cp cpk study with excel template. 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 capability platform allows you to compare the capability of numerous variables in one plot.
Emphasis will be given on the correction of the common misconceptions through visual demonstrations using sas jmp s jsl interactive graphics. Version 1 of jmp went into production in october 1989. The capability index plot shows ppk values for all variables that you entered as y, process. 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. 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. See attached for some tips on calculating capability for unilateral tolerance. Interpret the key results for normal capability analysis. Calculating capability indices with one specification data. The issues with capability indices will be discussed in a future article.
Cpk is used to estimate how close you are to a given targe. 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. Jmp is used in applications such as six sigma, quality control. Some other topics will be included as well like discussions on spc, six sigma, and lean concepts. If possible, could you specify your answer on the above my questions. Key output includes the histogram, normal curves, and capability indices. From what i understand, jmp only provides cpk, but gives different options for the calculation.
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. Properties associated with control charts and capability. 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. 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. The capability to script and automate so many statistical approaches is a powerful tool that allows for users to really delve into repeated datasets. We will use process capability in jmp to generate a capability analysis. It shows how closely a process is able to produce the output to its overall specifications. The process capability index for a stable process, typically defined as. Usl upper specification limit, lsl lower specification limit. 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. These are used to compute short and longterm capability indices. Implementing and maintaining spc program important factors to consider and steps for effective implementation. The book assumes that you have the software at your school or office.
It only works if both sides are bounded, such as roundness. Let we understand this concept with the help of a simple example. Jmp software is partly focused on exploratory data analysis and visualization. This paper addresses process capability and the new functionality the process capability platform brings to 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. P pk is used to assess the longterm, overall variability, whereas c pk is the capability index for shortterm, potential variability. The capability index is the ratio of the specification width to process width.
Distribution xy b yt fi tabulate text explorer covers how to perform bivariate, oneway anova, and contingency analyses through analyze fit y by x. Most software ive used will calculate short term capability cpk and long term ppk. Introduction a process capability index is a numerical summary that compares the behavior of a product. The presentation begins with a short introduction to process capability. If the process is in control and the distribution is well within the specification limits then the difference between the upper. So now we can confidently talk about process capability in terms of the indices cp and cpk.