Running head: Fujiyama Electronics, Inc. CASE STUDY

Fujiyama Electronics, Inc. Case Study
DeVry University, BSOP 326

Fujiyama electronics INTRODUCTION
Problem 1.
Fujiyama electronics has had difficulty with their circuit board manufacturing and has attempted to determine the problem. Thirty samples were taken of four boards each due to unacceptable variability and the results from each data set were placed in a chart. (Staff Writer, 2010)

CHART 1 – Sample Data DATA | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 1 | 4.92 | 4.65 | 5.77 | 6.25 | 5.27 | 5.22 | 5.47 | 5.71 | 5.24 | 4.42 | 5.14 | 4.92 | 5.79 | 4.92 | 5.68 | 2 | 4.26 | 5.54 | 5.26 | 4.88 | 5.41 | 5.38 | 4.68 | 4.54 | 5.58 | 5.18 | 4.26 | 5.78 | 3.83 | 4.8 | 5.74 | 3 | 4.94 | 5 | 4.76 | 5.66 | 6.02 | 5.08 | 4.56 | 4.17 | 4.72 | 4.79 | 4.71 | 5.5 | 4.3 | 4.75 | 4.65 | 4 | 4.29 | 5.42 | 4.79 | 4.44 | 4.91 | 4.65 | 4.7 | 4.87 | 5.41 | 4.73 | 5.48 | 5.05 | 4.78 | 5.59 | 5.2 | DATA | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 1 | 5.43 | 4.79 | 4.43 | 6.35 | 5.03 | 6.32 | 4.3 | 6.07 | 5.11 | 4.5 | 4.91 | 4.65 | 4.7 | 5.87 | 4.41 | 2 | 4.81 | 6.04 | 5.08 | 5.95 | 4.66 | 6.09 | 5.47 | 4.97 | 4.9 | 5.24 | 4.79 | 4.71 | 5.5 | 5.3 | 4.75 | 3 | 5.27 | 4.47 | 3.69 | 6.29 | 5.25 | 5.57 | 4.27 | 5.51 | 5.91 | 4.86 | 5.74 | 4.81 | 6.04 | 5.78 | 4.95 | 4 | 4.96 | 5.18 | 6.43 | 5.89 | 4.46 | 5.91 | 4.34 | 5.02 | 4.66 | 4.35 | 5.03 | 5.32 | 4.3 | 5.07 | 5.11 |

When the data was input into the chart, an X-Bar-Bar chart was made as well as an R-Bar chart. The initial results were an average of 5.1 and a range of 1.083. There were some data points that occurred outside of the control areas. The X-Bar chart shows the upper control limits and the lower control limits of the sample sets taken. The averages are seen crossing the center points of data on the chart with some crossing the upper control limit points. The points outside of the control limits skew the data samples. The points at 19 and 21 are seen to be above the upper control limit on the chart, see Chart 2.

CHART 2 – X-Bar Chart

The R-Bar chart is a second control chart that displays the range of the data from the samples input. Those points that vary beyond the upper or lower control points should be recognized and removed to reduce variability. Point 18 is above the upper control limit and should be adjusted or removed in order to produce a more balanced control area.
CHART 3 – R Chart

Once the points have been identified, they will be removed and the control charts will display results between the upper and lower control limits. To get these results accurately displayed the variables are removed and this was accomplished by deleting 18, 19, and 21.
Following the changes, the results provided an average of 5.1 and a range of 1.083. The data points that occurred outside of the control areas are corrected and the remaining points are now between the upper and lower control levels.
CHART 4 – X-Bar Chart

The R chart was controlled when the numbers were removed for the X chart. This created a clear data set for the range. There is no longer a point outside of the upper control limit. It also provides a more even display of the data sets to assist in the drawing of a conclusion.

CHART 5 – R Chart

The first noticeable observation we can make is that when we remove three points, #18, #19, and #21, all of the out-of-control points are removed from the new Control Chart. There is also a noticeable change in the X-Bar where there is a more even dispersal of the numbers. The R-Bar has better line of flow with shorter control range.
The Control Limits on the changed X-Bar and R Charts have narrowed to display a tighter path along the center points. With the control points bound to the ranges set and not out of tolerance levels, the results are easier to recognize as regular occurrences. These occurrences are statistically capable of revealing the true states of the process.