Assignment #1 Directions The following series of questions co.docx
- 1. Assignment #1 Directions: The following series of questions connect with the picture above of women wearing Burqas in Afghanistan. Burqa – A loose garment covering the entire body and having a veiled opening for the eyes, worn by Muslim women. 1.How would a symbolic sociologist view the Burqa? Explain your answer? 2. How would a functional sociologist view the Burqa? Explain your answer 3. How would a conflict sociologist view the Burqa? Explain your answer. 4. Which one of the perspectives most match your own personal beliefs of the Burqa? Explain how. 5. Which of the perspectives does the following quote, by an Afghani teenager, most match and how? “I think wearing Burqa is nothing but a shame to our whole nation and such a huge violence toward women. It was first brought by Taliban, we never had such a thing in our culture and history before. It is obvious that women who wear burqas do not do it by their own choice or understanding, they have been forced to wear them and obey the men of the family. Even though, it has been almost removed from Kabul, there are other provinces still using them and it makes me really angry and dishonored.” - Mansoora, 18yrs old, Kabul, Afghanistan
- 2. Copyright © 2016 John Wiley & Sons, Inc. Chapter 6 - Statistical Quality Control (SQC) Operations Management 6th Edition R. Dan Reid & Nada R. Sanders * * Copyright © 2016 John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc. Learning ObjectivesDescribe categories of statistical quality control (SQC).Identify and describe causes of variation.Explain the use of descriptive statistics in measuring quality characteristics.Describe the use of control charts.Identify the differences between x-bar and R-charts. * Copyright © 2016 John Wiley & Sons, Inc. Learning Objectives - cont'dIdentify the differences between p- and c-charts.Explain the meaning of process capability and the process capability index.Explain the concept Six Sigma.Explain the process of acceptance sampling and describe the use of operating characteristic (OC) curves.Identify decisions that managers must make when implementing SPC.Describe the challenges inherent in measuring quality in service organizations.
- 3. * Copyright © 2016 John Wiley & Sons, Inc. What is SQC? Statistical Quality Control (SQC) the term used to describe the set of statistical tools used by quality professionals to evaluate organizational quality. * Copyright © 2016 John Wiley & Sons, Inc. 3 Categories of SQC Statistical process control (SPC) inspecting a random sample of an output from process, within range and functioning properly Descriptive statistics the mean, standard deviation, and range Involve inspecting the output from a process Quality characteristics are measured and charted Helps identify in-process variations Acceptance sampling used to randomly inspect a batch of goods to determine acceptance/rejection Does not help to catch in-process problems * Copyright © 2016 John Wiley & Sons, Inc. Sources of VariationVariation exists in all processes.Variation can be categorized as either:Common or Random causes of variation, orRandom causes that we cannot identifyUnavoidable, i.e.; slight differences in process variables like diameter, weight, service time, temperatureAssignable causes of variationCauses can be identified Eliminate cause i.e.; poor
- 4. employee training, worn tool, machine needing repair * Copyright © 2016 John Wiley & Sons, Inc. Descriptive Statistics The Mean- measure of central tendency The Range- difference between largest/smallest observations in a set of data Standard Deviation measures the amount of data dispersion around mean Distribution of Data shapeNormal or bell shaped orSkewed * Copyright © 2016 John Wiley & Sons, Inc. Distribution of Data Normal distributions Skewed distribution * Copyright © 2016 John Wiley & Sons, Inc. SPC Methods-Developing Control Charts Control Charts (aka process or QC charts) show sample data plotted on a graph with CL, UCL, and LCL Control chart for variables are used to monitor characteristics that can be measured, e.g. length, weight, diameter, time Control charts for attributes are used to monitor characteristics
- 5. that have discrete values and can be counted, e.g. % defective, # of flaws in a shirt, etc. * Copyright © 2016 John Wiley & Sons, Inc. Setting Control Limits * * Copyright © 2016 John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc. Control Charts for VariablesUse x-Bar and R-bar charts togetherUsed to monitor different variablesx-Bar and R-bar charts reveal different problemsWhat is the statistical control difference from one chart to the next? * Copyright © 2016 John Wiley & Sons, Inc. Control Charts for VariablesUse x-Bar charts to monitor the changes in the mean of a process (central tendencies)Use R-bar charts to monitor the dispersion or variability of the process System can show acceptable central tendencies but unacceptable variability System can show acceptable variability but unacceptable central tendencies *
- 6. Copyright © 2016 John Wiley & Sons, Inc. Constructing an x-Bar Chart: A quality control inspector at the Cocoa Fizz soft drink company has taken three samples with four observations each of the volume of bottles filled. If the standard deviation of the bottling operation is .2 ounces, use the below data to develop control charts with limits of 3 standard deviations for the 16 oz. bottling operation. * Center line and control limit formulasTime 1Time 2Time 3Observation 115.816.116.0Observation 216.016.015.9Observation 315.815.815.9Observation 415.915.915.8Sample means (X-bar)15.87515.97515.9Sample ranges (R)0.20.30.2
- 7. Solution and x-Bar Control Chart * Control limits for±3σ limits: Center line (x-double bar): Copyright © 2016 John Wiley & Sons, Inc. x-Bar Control Chart * Copyright © 2016 John Wiley & Sons, Inc. Control Chart for Range (R) Center Line and Control Limit formulas: * Factors for three sigma control limits
- 12. Copyright © 2016 John Wiley & Sons, Inc. R-Bar Control Chart *
- 13. Copyright © 2016 John Wiley & Sons, Inc. Second Method for the x-Bar Chart Using R-bar & A2 Factor Use this method, Control limits solution, when sigma for the process distribution is not known: * Copyright © 2016 John Wiley & Sons, Inc. Control Charts for Attributes–P-Charts & C-Charts Attributes are discrete events: yes/no or pass/fail Use P-Charts for quality characteristics that are discrete and involve yes/no or good/bad decisionsNumber of leaking caulking tubes in a box of 48Number of broken eggs in a carton Use C-Charts for discrete defects when there can be more than one defect per unitNumber of flaws or stains in a carpet sample cut from a production runNumber of complaints per customer at a hotel *
- 14. * Copyright © 2016 John Wiley & Sons, Inc. P-Chart Example: A production manager for a tire company has inspected the number of defective tires in five random samples with 20 tires in each sample. The table below shows the number of defective tires in each sample of 20 tires. Calculate the control limits.