ACCURACY ANALYSIS OF WRIGHT’S CAPABILITY INDEX “CS” AND MODELLING NON-NORMAL DATA USING STATISTICAL SOFTWARE-A COMPARATIVE STUDY
Journal Title: International Journal for Quality Research - Year 2015, Vol 9, Issue 2
Abstract
Process Capability Indices (PCI) has been widely used as a means of summarizing process performance relative to set of specification limits. The proper use of process capability indices are based on some assumptions which may not be true always. Therefore, sometime whether the process capability indices can truly reflect the performance of a process is questionable. Most of PCIs, including Cp, Cpk, Cpm and Cpmk, neglect the changes in the shape of the distribution, which is an important indicator of problems in skewness-prone processes. Wright proposed a process capability index ‘Cs’ to detect shape changes in a process due to skewness by incorporating a penalty for skewness. In this paper, the effect of skewness on assessment of accuracy of Wright’s capability index Cs is studied and comparison is made with Cp, Cpk, Cpm and Cpmk indices when the distribution of the quality characteristic (spring force) considered is skewed slightly. This paper also discusses how modelling the non normal data using statistical software and results were compared with other methods.
Authors and Affiliations
Yerriswamy Wooluru, D. R. Swamy, Nagesh P Nagesh
APPLICATION AND VALIDATION OF DMAIC SIX SIGMA TOOL FOR ENHANCING CUSTOMER SATISFACTION IN A GOVERNMENT R&D ORGANIZATION
This study was carried out to explore and validate DMAIC six sigma tool to enhance the customer satisfaction in an ISO 9001: 2008 certified government R&D organization. The organization chosen for this study has implemen...
INCORPORATING KANSEI ENGINEERING INTO SERVICE QUALITY TOOLS TO IMPROVE THE AIRLINE SERVICES
The aviation industry in Indonesia continues to grow rapidly in the recent years. In 2015, ASEAN Open Sky, the policy of liberalization of air transportation in Southeast Asia was applied and opened the airspace between...
BEHAVIOR QUALITY DECIDES OUR CONDITIONS OF SURVIVAL AND DEVELOPMENT
Background of the topic: The unusual significance of quality has been found, attribute quality concept (quality is the general nature of its supporter) has been found, the quality exchange law and the standard to one’s l...
Forecasting And Analysis Of Trends In Area Of Quality Management System
This research presents chronology and trends in area of quality management system through nonconformities. The aim of the work is to forecast possible scenario to foresee activities for future period and time what will p...
LEAN MANUFACTURING IN TWO SERBIAN FOOD COMPANIES – CASE STUDIES
This paper gives an overview of a 9 month experience in implementing lean manufacturing tools in two Serbian food companies. Both companies have certified quality and food safety management systems and are food exporters...