Quality Assurance - Selected Gender Equality - Selected
Determining and Assessing Process Capability for Engineers and Manufacturing
Book Description: Process capability continues to receive a great deal of attention from practitioners and researchers alike. Since Sullivan introduced the concept to North America, the focus on process capability is due in part to the changing philosophy in Quality Assurance. Slogans such as “doing things right the first time" and “building a quality product" are terrific motivators, however if a process is not capable of meeting requirements, resources will be wasted. For example, if a mechanical process is not capable, the operators, regardless of their dedication and effort, will be unable to produce a quality product. Similarly if the operators are not capable of meeting the demands of the machinery, a quality product will not result. Processes that are not capable, regardless of their incapacity, waste resources. The goal of the book is to illustrate use of the most common process capability indices with the sincere hope that it will foster the safe use and development of PCIs among practitioners and researchers.Monetizing Process Capability
In conjunction with Bartholomew Leung of Hong Kong Polytechic University, we address a long standing concern raised by practitioners.Abstract
A major concern among managers and administrators has been the lack of cost assessment/financial implications associated with process improvement and process capability. The impact of process control frequently gets treated more as good will than actual cost savings. In this manuscript we provide methods for quantifying cost savings through use of the metrics used to assess and improve process performance and capability. Initially we develop the general relationship between process capability indices and financial costs using the process capability index Cpw and various loss functions. The relationship between the unified approach for some common process capability indices (PCIs) through the use of a non-stochastic weight function and the expected weighted squared error loss provides an intuitive interpretation of Cpw. Using different values of the non-stochastic weights, w, the distributions of the estimated loss associated with the measures of process capability indices can be determined. Upper confidence limits for the expected loss associated with Cpw as well as its generalization Cpw*, and special cases such as Cp, Cp*, Cpm, Cpm*, Cpk and Cpk* are discussed. Quality practitioners and manufacturers need only specify the target, maximum loss, the estimated process mean and standard deviation, in order to determine an estimate of the expected loss associated with the process.
Exploring Data Structures with Mathematica7
Methods for estimating, assessing and monitoring processes are illustrated using the software package Mathematica7 from Wolfram. Graphical techniques that allow the dynamic assessment of underlying distributional properties as well as capabilities are presented and illustrated. In addition, innovative procedures associated with compositional data in the L3 space are examined and expanded to the L1 constrained space for two variables and the L2 space for three variables. Several new conventions are proposed that attempt to provide insights into a variety of processes, all with diagnostic tools useful for, but not limited to the manufacturing sector. Several estimation and inferential techniques are presented with tools for determining associated estimates and the resulting inferences. The manuscript is accompanied by a Mathematica7 notebook best viewed using Mathematica7 or Mathematica7 Player. Mathematica7 Player is a free download available at www.Wolfram.com/products/player/ that allows all features of the notebook to be viewed.This article appeared as a Chapter in
A Comparison of Process Capability Indices
This manuscript appeared as a Chapter inBayesian Approach to Estimating Process Capability
This manuscript appeared as a Chapter inA Customer Satisfaction/Process Capability Approach to Short Run Processes
Abstract
Short run processes pose many challenges to standard statistical process control methodologies. Classical short run approaches attempt to standardize the measurements before applying traditional control procedures. A technique is proposed that standardizes the measurements from a customer satisfaction perspective and then uses small sample process capability techniques to provide analytical control mechanisms for a class of short run processes. Examples from a custom print shop are used to illustrate the procedure.
This manuscript appeared inA New Measure of Process Capability: Cpm
A new measure of the process capability (Cpm) is proposed that takes into account the proximity to the target value as well the process variation when assessing process performance. The sampling distribution for an estimate of Cpm and some properties have been examined and an example of its application is included. The new index is easy to compute and , with the aid of the included tables, easy to analyze. The developed estimator of Cpm has some more desirable properties than estimators of competing indices Cp and Cpk.This manuscript appeared in
See also: Percent Non-conforming and Cpm in Quality Progress, August, 1991.
Assessing Process Capability in the Presence of Systematic Assignable Cause
A process must be considered free from variation due to assignable cause before its capability can be determined. In those situations where variation due to an assignable cause occurs and is tolerated, process capability cannot be assessed. By allowing the process capability to be considered dynamic, a procedure for assessing capability is proposed and an estimator developed for those situations where a systematic assignable cause occurs. Some statistical properties of the estimator are examined and a technique for managing a process exhibiting a systematic assignable cause is discussed. Examples from a particular class of systematic assignable cause known as tool wear are included.This manuscript appeared in
A General Class of Loss Functions with Industrial Applications
Over the last few years, loss functions have become increasingly important in quality assurance settings. In this article, we develop a class of loss functions based on inversions of probability density functions and present industrial examples to illustrate monitoring and control using economic loss instead of measurements. Industrial applications are illustrated.This article appeared in
See also: The reflected normal loss function in The Canadian Journal of Statistics, 21(3), 1993.
The Sensitivity of Common Capability Indices to Departures from Normality
The process capability index Cpw provides a general representation for a wide variety of process capability indices including Cp, Cpk, Cpm and Cpmk. In this article we will develop a procedure to investigate the sensitivity of Cpw to departures from normality and discuss the impact on inferences drawn for a variety of regions and weights. The focus will be on the widely used indices and in particular those indices whose inference focuses on the ability of the process to be clustered around the target. The robustness of estimates of Cpw to distributional assumptions and the resulting impact on the inferences are compared.This article appeared as a Chapter in
Exploring Process Capability with Mathematica
Several methods for estimating, assessing and monitoring process capability are illustrated using the software package Mathematica7 by Wolfram. Graphical techniques that allow assessment of the underlying distributional properties of the process data as well as process capability are presented and illustrated. Several new conventions are proposed that attempt to provide insights into the process with diagnostic tools useful for, but not limited to the manufacturing sector. Several estimation and inferential techniques for the more common indices are presented with tools for determining associated values and the resulting inferences. This notebook is best viewed using Mathematica7 or Mathematica Player7. Mathematica Player7 is a free download available at www.Wolfram.com/products/player/ that allows all features of the notebook to be viewed.This article appeared in
A View of Jamaica’s Murder Victims, Perpetrators & the Impact of the 2010 Incursion
Abstract
In this manuscript we investigate homicides in Jamaica for the period 2007-2012. Several views of the available data are presented in an attempt to highlight statistically significant changes in murder rates as well as to indicate areas where there has been virtually no change in frequencies or patterns. As we begin to better understand the dynamics behind the victims and perpetrators of murder through statistical analyses, those initiatives that target crime and homicide reduction should become more efficient and effective. Some commentary is included in order to provide background and support for the statistical tools used.
Investigating Gender Violence In Jamaica
Abstract
As Jamaica moves through implementation of their National Policy on Gender Equality and develops harassment legislation, this manuscript attempts to investigate current levels and trends of gender based violence in Jamaica. All analyses make use of existing data and data formats in developing performance indicators that illustrate the current state of gender violence in Jamaica. The analyses provide a baseline for the future assessment and comparison with internationally accepted gender based violence indicators. All source data has been included to facilitate comparisons and discussions regarding related levels and trends of violence as well as addressing performance indicator effectiveness.
Violence and Victims, 29(6), doi http://dx.doi.org/10.1891/0886-6708.VV-D-12-00156.Introducing Statistics within a Gender Focal Point Strategy
Abstract
The United Nations Development Strategy for Gender in Development Programme relies heavily on two key components. The first is the strategy or problem solving technique often referred to as the Plan-Do-Check-Act (PDCA) cycle (or the PLANNING AND REVIEW CYCLES IMPLEMENTATION) and the second the Gender Focal Points. The PDCA cycle is a mechanism for planning, documenting, analyzing, implementing and verifying the impact of a plan or strategy and the GFPs are the resources critical to the implementation of the PDCA. This manuscript a) outlines the key components of the PDCA cycle along with tools associated with each of the four stages in the cycle and b) provides a gender based approach to integrating the concepts of statistics into the Gender Focal Point training regimen. A series of ten modules, each taking less than 120 minutes to present, have been developed using Microsoft Office’s PowerPoint, Word and Excel. The ten modules were developed in conjunction with, and for use by, the Bureau of Women’s Affairs, Office of the Prime Minister, Government of Jamaica. The PowerPoint presentations, related datasets, questionnaires and supporting material are available from the author.
Measuring and Assessing Gender Violence
Abstract
As Jamaica moves through implementation of their National Policy on Gender Equality (NPGE) and develops harassment legislation, there is a need to be able to identify and assess the impact of such programs and initiatives. In addition Funding Agencies are increasingly requiring evidence that developed initiatives are reaching their target audience and are having a measurable impact. With the assistance of the Jamaica Constabulary Force, procedures for monitoring and assessing Violence, Gender Based Violence, Domestic Violence and Intimate Partner Violence are proposed and illustrated.
The article first appeared in theInvestigating Gender and Gender Based Violence In Jamaica
Abstract
As Jamaica moves through implementation of its National Policy on Gender Equality and develops harassment legislation, there is a growing need to develop methodology and identify data sources that will facilitate assessment of these programs and initiatives. This case study details the research, developed methodology and steps taken to better understand gender and gender-based violence in Jamaica. I start by reviewing existing gender violence documentation, developing definitions that address gender violence in Jamaica, identify data sources, conduct a gap analysis and conclude with summaries of the current state of gender violence in Jamaica. All analyses make use of existing data and data formats in developing performance indicators that illustrate the current state of gender violence in Jamaica. I conclude with a call for a shift in the data and data acquisition to provide a better fit for the global gender violence performance indicators.
The article first appeared in the