Operation management Essay Example | Topics and Well Written Essays - 1000 words - 2

Operation management - Essay Example A trend is observed in the x bar chart for size of the dolls making it a focus area for the company. There have been a lot of customer returns due to inconsistencies in the colour and the size of the dolls manufactured in the plant. In order to analyze the situation, the company recorded 2 sets of data. The first set contains the number of colouring defects over a period of 30 days. The second set contains the sizes of 3 dolls selected at random daily over a period of 30 days. The company needs to find out whether its processes are in control or not. C-chart is the most appropriate control chart for the number of defects found if the sample size remains the same throughout. For the first data set the sample size for testing in each of the 30 subgroups is 200. Thus, using c-chart makes absolute sense. The 3 sigma control limits for a c-chart are calculated as: In the R-chart and x bar chart for height of the dolls, many observations lie outside both the control limits. This shows that the process is out of control. R-chart is shown in Figure 3.2 and x bar chart is shown in Figure 3.3. The manufacturing process of the toy plant is out of control for both the number of defectives in colour and the heights of the dolls. Since, only 1 observation is out of limits for colour defects, it may be considered as a one-off deviation and can be neglected. However, the company must still aim to decrease the mean number of defects. This could be done by replacement of the machine which would require a capital expenditure. The ultimate aim of the company must be to go for zero defects as proposed by quality experts. This is also a key philosophy of Lean Management and Six Sigma. From the point of view of heights of dolls, the process is completely out of control. Sharp trends are visible in the R chart and x bar chart. This implies a problem with the production process. This variation is a controlled variation and rectifying the production process will