Preview

Statistical Quality Control

Powerful Essays
Open Document
Open Document
2335 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Statistical Quality Control
INTRODUCTION

Have you experienced purchasing a product then discovered that it is defective in some way or does not function the way it was designed to, or found that a piece of the product is missing or defective. As consumers, we expect the products we purchase to function as intended. However, producers of products know that it is not always possible to inspect every product and every aspect of the production process at all times. The challenge is to design ways to maximize the ability to monitor the quality of products being produced and eliminate defects. (TQM) addresses organizational quality from managerial viewpoints focusing on customer-driven quality standards, managerial leadership, continuous improvement, quality built into product and process design, quality identified problems at the source, and quality made everyone’s responsibility. However, talking about solving quality problems is not enough. We need specific tools that can help us make the right quality decisions. These tools come from the area of statistics and are used to help identify quality problems in the production process as well as in the product itself. Statistical Quality Control (SQC) is a set of statistical techniques intended to aid in the improvement of system quality.[i]

DEFINITION

The Statistical Control of Quality is application of statistical principles and techniques in all stages of design, production, maintenance and service. The phrase “statistical quality control” (SQC) refers to the application of statistical methods to monitor and evaluate systems and to determine whether changing key input variable (KIV) settings is appropriate. Specifically, SQC is associated with Shewhart’s statistical process charting (SPC) methods. These SPC methods include several charting procedures for visually evaluating the consistency of key process outputs (KOVs) and identifying unusual circumstances that might merit attention.

In common usage, however, SQC refers to many



References: Reid, R. D., & Sanders, N. R. (2005). Wiley. Retrieved December 12, 2008, from Wiley Website: http://www.wiley.com/college/sc/reid/chap6.pdf [ii] Allen, T. T. (2006). Part I - Statistical Quality Control. In Springer, Introduction To Engineering Statistics And Six Sigma (p. 47). Ohio: Springer-Verlag London Limited.

You May Also Find These Documents Helpful

  • Better Essays

    Introduction to SAS. UCLA: Statistical Consulting Group (2007). Retrieved on December 1, 2013 from http://www.ats.ucla.edu/stat/sas/notes2/…

    • 1093 Words
    • 5 Pages
    Better Essays
  • Good Essays

    The main task of statistical process improvement methods such as Statistical Process Control, Six Sigma and Measurement Systems Analysis and the Taguchi approach to Experimental Design is to control and reduce process variation.…

    • 1701 Words
    • 7 Pages
    Good Essays
  • Good Essays

    Carl Rogers

    • 2040 Words
    • 9 Pages

    References: Thorne, Brian (2003). Grand Canyon University Library. Carl Rogers (2nd Edition). SAGE Publications Inc. (US) London, GBR.…

    • 2040 Words
    • 9 Pages
    Good Essays
  • Good Essays

    MGC1 PRE-ASSESSMENT

    • 1427 Words
    • 6 Pages

    11. The introduction of statistical tools to analyze the causes of product defects is associated with which quality…

    • 1427 Words
    • 6 Pages
    Good Essays
  • Good Essays

    OM 300 Exam 2 Cheat Sheet

    • 1229 Words
    • 4 Pages

    A process that monitors standards by take measurements and corrective action as needed. It is in control when only variation is natural, if variation is assignable then discover cause eliminate it. Take samples to inspect/ measure- reduce inspection time, reduce opportunity of bad quality. Control charts graph of process data over time-show natural and assignable causes. Control charts for variable data (characteristic that is measured, length,height, etc) are X-chart (average) and R-chart (range)must use x and r to get correct results. central limit theorem follow normal curve. When we know . When we don’t know . Control charts for attributes (categorical-defective, good/bad) P-chart (percent) or C-chart (count number). . X-bar chart is sensitive to process mean, R-bar chart is sensitive to process standard deviation. 3 management issues for control charts. 1. Select points that need SPC. 2. Determine charting technique. 3. Set clear policy/procedure. Process capability ability to meet design specifications/Measure of relationship between natural variation of process and design specifics. to be capable. Acceptance sample- take random samples, inspect, deiced whether to reject the whole lot based on results. Only screen lots. Automated inspection 100% inspection at low costs.…

    • 1229 Words
    • 4 Pages
    Good Essays
  • Better Essays

    Stevenson, W. (2009). Statistical Process Control. In W. Stevenson, Operations Management, 10th Edition (p. 486). McGraw-Hill Higher Education.…

    • 6170 Words
    • 25 Pages
    Better Essays
  • Good Essays

    Bennett-Alexander, D., & Hartman, L. P. (2007). [University of Phoenix Custom Edition eBook]. : McGraw Hill. Retrieved from University of Phoenix, MGT/434 website…

    • 1070 Words
    • 5 Pages
    Good Essays
  • Better Essays

    OM300 Study Guide 22

    • 1172 Words
    • 4 Pages

    The objective of a process control system is to provide a statistical signal when assignable causes of variation are present “ if you can’t describe and measure it the you can’t control or improve it.” SPC a process used to monitor standards by taking measurements and corrective action as a product or service is being produced. Control chart a graphical presentation of process data over time. A process is said to be orperating in SC when only source of variation is common(natural) causes. The process must first be brought in statistical control by dectecting and elimination special(assignable) causes of variation. The objective of Process Control Sysytem is to provide a statistical signal when assignable causes of variation are present. Natural variation variability that affects every production process to some degree and is to be expected also known as common cause. Control charts for the mean x or x-bar and the range R are used to monitor processes that have variables (continuous dimensions). X-chart tells us whether changes have occurred in the central tendency(the mean) of a process. The R-chart values indicate that a gain or loss in dispersion has occurred. The theoretical foundation for x-charts is the central limit theorem which states that regardless of the distribution of the population of all parts or services, the distribution of x’s tends to follow a normal curve as the number of samples increases. 95.45 % +/- 2 std dev. 99.73% +/- 3 std dev. Attributes are typically classified as defective or nondefective. 2 attribute charts p-chart measure the percent defective in a sample and c-chart count the number of defects in a sample. Acceptance sampling method of measuring random samples of lots or batches of products against predetermined standards.…

    • 1172 Words
    • 4 Pages
    Better Essays
  • Good Essays

    Gary Paulsen

    • 508 Words
    • 3 Pages

    Thomson, S. L. (2003). Gary Paulsen - Google Books . Retrieved April 18, 2008, from Google Books : http://books.google.com…

    • 508 Words
    • 3 Pages
    Good Essays
  • Better Essays

    Cited: Kroenke, David M. (2013). Using MIS (6th edition). Upper Saddle River, New Jersey, United States of America: Pearson Education, Inc., publishing as Prentice Hall.…

    • 1735 Words
    • 7 Pages
    Better Essays
  • Good Essays

    Dav Case Study

    • 1003 Words
    • 3 Pages

    Statistical Process Control is an effective method of monitoring a process through the use of control charts. It would involve using Statistical techniques to measure and analyze the variation in processes. It can detect the presence of special causes of variation.…

    • 1003 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    ¨Statistical process control (SPC) involves using statistical techniques to measure and analyze the variation in processes. Most often used for manufacturing processes, the intent of SPC is to monitor product quality and maintain processes to fixed targets. Statistical quality control refers to using statistical techniques for measuring and improving the quality of processes and includes SPC in addition to other techniques, such as sampling plans, experimental design, variation reduction, process capability analysis, and process improvement plans.¨(reliability.sandia.gov, Statistical Process Control)…

    • 501 Words
    • 2 Pages
    Satisfactory Essays
  • Better Essays

    Delta Plastics, Inc. (B)

    • 689 Words
    • 3 Pages

    Discuss whether or not both materials are in control and what conclusion may be drawn.…

    • 689 Words
    • 3 Pages
    Better Essays
  • Powerful Essays

    Polaroid Case

    • 1849 Words
    • 8 Pages

    * Introduces the construction and use of statistical process control (SPC) charts and an understanding of the relationship between SPC and conformance quality.…

    • 1849 Words
    • 8 Pages
    Powerful Essays
  • Satisfactory Essays

    House of quality (HOQ), building a HOQ, QFD process. Failure mode effect analysis (FMEA) –…

    • 263 Words
    • 2 Pages
    Satisfactory Essays