Assignment 5: Statistical Process Controls. Laura M Williams, RN, CLNC, MSN. IET603: Statistical Quality Assurance in Science and Technology

Transcription

1 Running head: WILLIAMS ASSIGNMENT Assignment : Statistical Process Controls, RN, CLNC, MSN IET60: Statistical Quality Assurance in Science and Technology Morehead State University Dr. Ahmad Zargari 8 March 204

2 Quantity Returned Percent Williams Assignment 2 Statistical Process Controls: Please solve and submit the following questions (0 points).. A major record-of-the-month club collected data on the reasons for returned shipments during a quarter. Results are: wrong selection, 0,000; refused,,000; wrong address, 68,000; order canceled,,000; and other,,000. Construct a Pareto diagram and recommend what are the major problems that demand investment Reason for Return Williams - Assignment. Question : Pareto Chart Refused Wrong Address Wrong Selection Other Canceled Order Quantity Returned Percent Cum % This Pareto chart indicates customer refusal constitutes more than half of all returned shipments. This company should develop a policy which requires the customer to indicate the reason for refusal. 2. Calculate the average, median, mode, range, and standard deviation for each group of numbers. (a) 0, 4,,, 4, 0,, 4, (b) 8,8,88,8,86,82,84 (c),,4,2,2,4,4,,, (d) 6,2,8,,6,2,4 (e) 4,,42,42,4

3 Williams Assignment. Control charts for X and R are to be established on a certain dimension part, measured in millimeters. Data were collected in subgroup sizes of 6 and are given below. Calculate the trial central line and control limits. Assume assignable causes and revise the central line and limits Subgroup Subgroup Number X R Number X R

4 Mean Mean Williams Assignment 4 IET60 Spring 204 Assignment, Question a Xbar Chart of X UCL= X= LCL= January IET60 Spring 204 Assignment, Question a Xbar Chart of R UCL= X= LCL= January 204

5 Mean Mean Williams Assignment Revised to reflect removable of assignable causes: IET60 Spring 204 Assignment, Question b Revised Xbar Chart of X with Removal of Assignable Causes UCL= X= LCL= January IET60 Spring 204 Assignment, Question b Revised Xbar Chart of R with Removal of Assignable Causes UCL= X= LCL= January 204

6 Williams Assignment 6 4. The following table gives the average and range in kilograms for tensile tests on an improved plastic cord. The subgroup size is 4. Determine the trial central line and control limits. If any points are out of control, assume assignable causes, and determine the revised limits and central line.

7 Mean Mean Williams Assignment 0 00 IET60 Spring 204 Assignment, Question 4a Xbar chart of Weight in Kg UCL= X= LCL= January 204 IET60 Spring 204 Assignment, Question 4a Xbar chart of Weight Range UCL= X= LCL= January 204

8 Mean Mean Williams Assignment 8 Revised to remove assignable causes: IET60 Spring 204 Assignment, Question 4b Xbar chart of Weight in Kg with Assignable Causes Removed 00 UCL= X= LCL= January January 204 IET60 Spring 204 Assignment, Question 4b Xbar chart of Weight Range with Assignable Causes Removed UCL=2.22 X=2.2 LCL=2.028

9 Range Mean Williams Assignment. The Get-Well Hospital has completed a quality improvement project on the time to admit a patient using: XC- and R charts. They now wish to monitor the activity using median and range charts. Determine the central line and control limits with the latest data in minutes, as given here. Variable Mean StDev X.4 0. X X IET60 Spring 204 Get-Well Hospital Admission Time Observation Group X UCL= X= LCL=4.28 UCL=2.2 2 R=0.8 0 LCL= January 204

10 Mean Williams Assignment 0 6. The viscosity of a liquid is checked every half hour during one three-shift day. What does the run chart indicate? Data are, 42,8,,4,40,6,,,6,,4,8,6,2,,,4,,,2,8,4,,,, 4,,,, 2, 6,,2,,2,,0,2, and 2. 4 Xbar Chart of Viscosity UCL= X= LCL= Tests performed with unequal sample sizes This run chart indicates the viscosity of the liquid is consistently getting lower.

11 Proportion Williams Assignment. Determine the trial central line and control limits for a p chart using the following data, which are for the payment of dental insurance claims. Plot the values on graph paper and determine if the process is stable. If there are any out -of-control points, assume an assignable cause and determine the revised central line and control limits. 0.0 P Chart of Number Nonconforming UCL= P= LCL=

12 Count Per Unit Williams Assignment 2 8. Determine the trial limits and revised control limits for a u chart using the data in the table for the surface finish of rolls of white paper. Assume any out -of-control points have assignable causes. U Chart of Number Nonconformities UCL= U=.04 2 LCL=

13 Product Temperature Williams Assignment. A quality technician has collected data on the count of rivet nonconformities in four meters travel trailers. After 0 trailers, the total count of nonconformities is 6. Trial control limits have been determined and a comparison with the data shows no out-of-control points. What is the recommendation for the central line and the revised control limits for a count of nonconformities chart? 0. By means of a scatter diagram, determine if a relationship, exists between product temperatures and percent foam for a soft drink. 0.0 Temperature and Foam Relationship Foam % January 204