A NOVEL APPROACH FOR ESTIMATING THE ARL-BIAS SEVERITY OF SHEWHART P-CHARTS
Journal Title: International Journal for Quality Research - Year 2018, Vol 12, Issue 1
Abstract
The Shewhart p-Chart is a widely used and taught control chart that monitors the process fraction of nonconforming, p. The control limits of this chart are computed from an equation derived from the central limit theorem that assumes the parameters p and sample size, n, provide a good approximation of the binomial to the normal distribution. It is known that if the approximation is poor the chart becomes ARL-biased with a consequent deterioration of its process improvement detection capability. Hence, if one is to use this chart its ARL-biased severity ought to be established in advance. Three parameters are used to estimate a chart's ARL-bias severity, namely the in-control ARL, the relative ARL-bias and the maximum out of control ARL. However, calculating these parameters is a task that requires of lengthy calculations that often entails the use of specialised software. In this paper we present a new approach that facilitates the estimation of the bias severity, this approach consists of a closed-form equation that eases the calculations of the ARL-bias parameters and of a graphical method that permits assessing a p-Chart's ARL-bias severity level according to the severity zone in which its n and p values fall into.
Authors and Affiliations
Marco Antonio Argoti, Andrés Carrión García
Keywords
Related Articles
- EP ID EP266432
- DOI 10.18421/IJQR12.01-12
- Views 86
- Downloads 0
MONITORING, MEASUREMENT, ANALYSIS AND REVIEW IN POLISH AND MONTENEGRIN ORGANIZATIONS ACCORDING TO THE ISO 9004 MANAGEMENT MATURITY MODEL
The paper is result of studies conducted at the Center for Quality-Faculty of Mechanical Engineering-Podgorica and it specifically includes a detailed study and analysis of literature sources concerning innovation, quali...
PRIORITIZATION OF CUSTOMER NEEDS IN HOUSE OF QUALITY USING CONJOINT ANALYSIS
The priority structure of customer needs in House of Quality (HOQ) forms the basis for the company to make the product more attractive to customers. In the traditional Quality Function Deployment (QFD) approach, the prio...
UTILIZATION OF QUALITY TOOLS: DOES SECTOR AND SIZE MATTER?
This research focuses on the influence of company sector and size on the level of utilization of Basic and Advanced Quality Tools. The paper starts with a literature review and then presents the methodology used for the...
IMPLEMENTATION PRODUCTIVITY MANAGEMENT CYCLE WITH OPERATIONAL KAIZEN APPROACH TO IMPROVE PRODUCTION PERFORMANCE (CASE STUDY: PARS KHODRO COMPANY)
The aim of this study is Implementation of productivity Management Cycle with Operational Kaizen Approach to Improve Production Performance in Pars Khodro Car Corporation. In this intervention study, all 120 employees of...
MANAGEMENT OF THE ORGANIZATION BASED ON BALANCED SCORECARDS
This paper deals with the analysis of the Strategic Management System approach called Balanced Scorecard. At the very beginning of this article, the basic model of this system is presented with the detailed description o...