Statistical Process Control Essay

1250 words - 5 pages

Toni White

March 28, 2010

OPS/571

Week 5 – Statistical Process Controls

Statistical Process Control

Total Quality Management is a philosophy that stresses three principles for achieving high levels of process performance and quality: Customer Satisfaction, Employee Involvement, and Continuous Improvement in Performance. This paper will address a practical type of continuous improvement - the use of statistical process control.
One definition of statistical process control (SPC) is “the application of statistical techniques to determine whether a process is delivering what the customer wants” (Goetsch & Davis, 2006). SPC primarily involves using control charts to ...view middle of the document...

Typically, the elimination process includes development of standard work, error-proofing and training, however, additional measures can also be used.

Detecting Special Causes

According to Shewart, since control is not defined as the complete absence of variation, we do want to identify and eliminate special causes of variation (Pyzdek, 1980). The following is a list of special causes:
1. A special cause is indicated when a single point falls outside a control limit.
2. A special cause is indicated when two out of three successive values are: a) on the same side of the centerline, and b) more than two standard deviations from the centerline.
3. A special cause is indicated when eight or more successive values fall on the same side of the centerline.
4. A special cause is indicated by a trend of six or more values in a row steadily increasing or decreasing.
Control Charts for Variables
There are different types of control charts for use. They include:
I chart. Used to construct a confidence interval that moves through time, then by tracking how each new period’s data falls within that range to help in making judgment about how a process is performing. Used when individual data is unknown.
X-Bar and S-Chart. Used when each subgroup has more than one observation to account for the sample variations. In the example below, we have the average caloric intake using a sample of 5 days for 5 consecutive weeks.

|  |Wk 1 |Wk 2 |Wk 3 |Wk 4 |Wk 5 |
|count |5 |5 |5 |5 |5 |
|Xbar |1,182.80 |1,100.60 |1,114.60 |1,082.20 |1,184.80 |
|variance |2,627.70 |10,111.30 |3,804.80 |11,694.70 |1,279.70 |
|sdev |51.26 |100.55 |61.68 |108.14 |35.77 |
|minimum |1121 |1000 |1021 |900 |1143 |
|maximum |1250 |1250 |1189 |1189 |1232 |
|range |129 |250 |168 |289 |89 |
|  |  |  |  |  |  |
|confidence interval 95.% lower |1,119.15 |975.74 |1,038.01 |947.92 |1,140.38 |
|confidence interval 95.% upper |1,246.45 |1,225.46 |1,191.19 |1,216.48 |1,229.22 |

Xbar is the average for each day, sdev is the standard deviation for each day. If we take the average of the average (Xbarbar) we get 1133, and if we take the standard deviation of all the sample means (Sbar) we get 190.0. Now we...

Other Papers Like Statistical Process Control

Marketing Essay

280 words - 2 pages production, management processes, production processes, and inspection processes. The critical takeaway here is that QA equates to process observations. Quality assurance is measured through failure testing and statistical control. Failure testing determines the stress levels under which a product will fail by exposing it to unanticipated stresses, like intense vibration, temperature, and humidity. Stress testing uncovers problems that can be fixed

Process Improvement Plan Essay

1134 words - 5 pages identified in Week Ones project of examining a daily process that may requirement improvement, apply statistical process control, determine the effect of any seasonal factors, and apply confidence intervals to the data points collected over the last four weeks. Process Description The process from Week Ones project is ‘Making Dinner’ during the week days. The daily task of making dinner for a family takes time and commitment, if time can be

Soc Sci Researches

306 words - 2 pages |When objective is to determine |When objective is to find out |When objective is to find out | | |the growth and development of a |process in depth |general picture of people’s |the cause and effect |the type or quality of messages |the economic viability of | | |group, organization or | |awareness

Architecture For Statistical Multiplexer

1801 words - 8 pages assumption a statistical service can improve upon a deterministic service by (1) taking advantage of knowledge about the statistics of traffic sources, and (2) by taking advantage of the statistical independence of flows [2]. The proposed model frees network operators from the manual and error-prone bandwidth reservation process which is currently used in practice. Features of this model are, reasonable bandwidth utilization, robustness to

Production And Operation Management

1153 words - 5 pages Plastic key chains are being produced in a company named Hot Shot Plastics. The plastic material is first molded and then trimmed to the required shape. The current curetimes (which is the time for plastic to cool) during the molding process affect the edge quality of the key-chains produced. The aim is to achieve statistical control of the curetimes using Xbar and R-charts Curetime data of 25 samples, each of size 4 have been taken when the

Use Of Statistical Information

1115 words - 5 pages highest quality of patient care as it relates to infection prevention and control. The primary responsibility of infection prevention and control is to use the data obtained and create proper policies and procedures that reduce the risk of patients acquiring an infection during their hospitalization. “At its most basic level, statistical quality control is rooted in the graphical and statistical analysis of process data for the purpose of

Analysis of a Monarch Butterfly Research Report

1164 words - 5 pages Analysis of a Monarch Butterfly Research Report David Bell HCS438 July 5, 2010 Keith Harris PhD Analysis of a Monarch Butterfly Research Report Statistics are a critical part of performing research studies. Researchers make use of a variety of statistical analyses to analyze data and make meaningful conclusions. Examining an example of a research study is an effective way to understand how such analyses are used in the research process

Dr. Kaoru Ishikawa Research Paper

889 words - 4 pages Quality Control was then translated into English in 1971, the most recent (2nd) edition being published by the Asian Productivity Organization in 1986. Amongst other books, he subsequently published What is Total Quality Control? The Japanese Way, which was again translated into English. He died in April 1989. (Process Reveiw and improve Office, 2002) Kaoru Ishikawa dedicated much of his efforts to making technical statistical techniques used in

Qnt561 Course Design

2138 words - 9 pages | Syllabus School of Business QNT/TM561 Version 2 Research and Statistics for Process Control | Copyright Copyright © 2009, 2005 by University of Phoenix. All rights reserved. University of Phoenix® is a registered trademark of Apollo Group, Inc. in the United States and/or other countries

Quality Management

914 words - 4 pages because it does not meet specifications, and cost arising from the process failures such as unplanned machine downtime and unplanned equipment repair. * External failure costs: Costs incurred after poor-quality products reach the customer. For example, while customer complaints and return the product, a company has to bear transportation cost, or replacement a new product to its customers. 3. What does the term “in statistical control

Principles of Six Sigma

1074 words - 5 pages * Effects analysis | * Measurement | * Process capability * Measurement systems analysis | * Process control | * Control plans * Statistical process control | * Process improvement | * Process improvement planning * Process mapping * Mistake proofing | * Implementation and teamwork | * Organizational effectiveness * Team assessment * Facilitation tools * Team development |

Related Essays

Statistical Process Control Essay

1560 words - 7 pages random, regular, haphazard, important, or evidence of a problem. The monitoring and controlling should be applied to the process not the product, and can be greatly facilitated by S.P.C.Process control means controlling production by checking its quality while the work is still in process. Implementing S.P.C. means applying statistical techniques and analysis to that control function. As S.P.C. is about measuring the quality of work in process, its

Case Study 5: Statistical Process Control

996 words - 4 pages CASE STUDY 5: Statistical Process Control Ikrom Abdullaev M0158958 Shamil Tlukashaev Chuan Lai Exercise A: Control Charts for Variables Step 1: Gather data Four samples of five observations (launches) each were arranged in tabular form. The mean and range for each sample determined and computed the mean of the means and the mean of the ranges. Data Table SampleNumber | Observation 1

Statistics Paper

449 words - 2 pages statistical procedure, for example, how a sampling method in quality control process select samples, what kind of analysis would be applied to the data and what conclusion would be made based of the findings. 3. The creativeness of the statistical solution. Some of the traditional statistical analysis that has been in place for years will weigh less as compared to the newer cutting-edge approaches to emerging problem more related to the information

Process Improvement Plan Essay

1054 words - 5 pages Process Improvement Plan OPS/571 The process improvement plan suggests a way to improve upon a process to eliminate wasted time. Getting to work on time is a valued because not doing so may cause termination of services. This is a plan to refine the structure of a process, as opposed to explaining problems singularly. This is done by the statistical process control, control limit, and confidence intervals. Statistical process control (SPC