Question

In: Statistics and Probability

Suggest a use for an attribute chart in the Education field (as opposed to manufacturing scenarios...

Suggest a use for an attribute chart in the Education field (as opposed to manufacturing scenarios typically demonstrated). Provide the metric with data and how it is calculated along with how this information would be tracked and interpreted.

Solutions

Expert Solution

Attribute Charts are a set of control charts specifically designed for Attributes data. Attribute charts monitor the process location and variation over time in a single chart.

The family of Attribute Charts include the:

Np-Chart: for monitoring the number of times a condition occurs, relative to a constant sample size, when each sample can either have this condition, or not have this condition

p-Chart: for monitoring the percent of samples having the condition, relative to either a fixed or varying sample size, when each sample can either have this condition, or not have this condition

c-Chart: for monitoring the number of times a condition occurs, relative to a constant sample size, when each sample can have more than one instance of the condition.

u-Chart: for monitoring the percent of samples having the condition, relative to either a fixed or varying sample size, when each sample can have more than one instance of the condition.

When to Use an Attribute Chart

Only Attributes data can be applied to an Attributes control chart.

To illustrate the differences between various attribute charts, consider an example of the errors in an accounting process, where each month we process a certain number of transactions.

The Np-Chart monitors the number of times a condition occurs, relative to a constant sample size, when each sample can either have this condition, or not have this condition. For our example using this type of attribute chart, we would sample a set number of transactions each month from all the transactions that occurred, and from this sample count the number of transactions that had one or more errors. We would then track on the attribute control chart the number of transactions with errors per month.

The p-Chart monitors the percent of samples having the condition, relative to either a fixed or varying sample size, when each sample can either have this condition, or not have this condition. For our example using this type of attribute chart, we might choose to look at all the transactions in the month (since that would vary from month to month), or a set number of samples, whichever we prefer. From this sample, we would count the number of transactions that had one or more errors. We would then track on the attribute control chart the percent of transactions with errors per month.

The c-Chart monitors the number of times a condition occurs, relative to a constant sample size. In this case, a given sample can have more than one instance of the condition, in which case we count all the times it occurs in the sample. For our example using this type of attribute chart, we would sample a set number of transactions each month from all the transactions that occurred, and from this sample count the total number of errors in all the transactions. We would then track on the attribute control chart the number of errors in all the sampled transactions per month.

The u-Chart monitors the percent of samples having the condition, relative to either a fixed or varying sample size. In this case, a given sample can have more than one instance of the condition, in which case we count all the times it occurs in the sample. For our example using this type of attribute chart, we might choose to look at all the transactions in the month (since that would vary month to month), or a set number of samples, whichever we prefer. From this sample, we count the total number of errors in all the transactions. We would then track on the attribute control chart the number of errors per transactions per month.

Each attribute control chart includes statistically determined upper and lower control limits, indicating the bounds of expected process behavior. The fluctuation of the points between the control limits is due to the variation that is intrinsic (built in) to the process. We say that this variation is due to "common causes" that influence the process. Any points outside the control limits can be attributed to a special cause implying a shift in the process. When a process is influenced by only common causes, then it is stable, and can be predicted. Thus, a key value of the control chart is to identify the occurrence of special causes, so that they can be removed, with a reduction in overall process variation. Then, the process can be further improved by either relocating the process to an optimal average level, or decreasing the variation due to common causes.

Attribute control charts are fairly simple to interpret: merely look for out of control points. The control limits may vary on the P chart and the U chart, based on the different sample sizes used for each plotted point. If the sample size does not vary by more than 10 or 15%, then you can use the average sample size on these charts to determine common control limits for all samples. This is often an option on your SPC software

If there are special causes, they must be understood. Brainstorm and conduct Designed Experiments to find those process elements that contribute to sporadic changes in process location. Remove the statistical bias of the out of control points by dropping them from the calculations of the process center line and its control limits. (This can be done automatically using the Auto Drop feature in our SPC software).

Remember that the variation within control limits is due to the inherent variation in sampling from the process. (Think of the Deming Red Bead experiment: the proportion of red beads never changed in the bucket, yet each sample had a varying count of red beads). The bottom line is: React first to special cause variation. Once the process is in statistical control, then work to reduce variation and improve the location of the process through fundamental changes to the system.


Related Solutions

Suggest a use for an attribute chart in the Education field. Provide the metric and how...
Suggest a use for an attribute chart in the Education field. Provide the metric and how it is calculated along with how this information would be tracked and interpreted.
describe a time when you had to use attribute analyis in the field. were you aware...
describe a time when you had to use attribute analyis in the field. were you aware of the different analytic tools that you could use? would you do anything different?
Education, Outline the most significant obstacles to obtaining an education in developing countries. Suggest at least...
Education, Outline the most significant obstacles to obtaining an education in developing countries. Suggest at least two reasons why education should be a priority in the developing world. Next, purpose significant overall strategies- aside from building more schools-that those in leadership positions in developing countries may use in order to help their people escape poverty through education.
34.​State one distinguishing characteristic of a qualitative research ……………………………………………………………………………………………………… 35.​Suggest an attribute of constructionism stance of...
34.​State one distinguishing characteristic of a qualitative research ……………………………………………………………………………………………………… 35.​Suggest an attribute of constructionism stance of research ……………………………………………………………………………………………………… 36.​List two characteristics of specific objectives for a research ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… 37.​Outline the whole process of data collection ………………………………………………………………………………………………………
The J H group Manufacturing has decided to use a p-Chart to monitor the proportion of...
The J H group Manufacturing has decided to use a p-Chart to monitor the proportion of defective washers produced by their production process. The control limits on these charts will be designed to include 97% of the sample proportions when the process is In Control. The quality control manager randomly samples 300 washers at 14 successively selected time periods and counts the number of defective washers in the sample. Sample   Defects 1   13 2   11 3   8 4   10 5  ...
In the following chart, fill in the missing cells for each of the following independent scenarios....
In the following chart, fill in the missing cells for each of the following independent scenarios. Do not enter dollar signs or commas in the input boxes. Round all answers to the nearest whole number, except for the CM Ratio. Round the CM Ratio to 2 decimal places. Scenario Revenue Variable Costs Fixed Costs Total Costs Operating Income CM Ratio Contribution Margin 1 $610 $Answer $490 $630 $-20 Answer% $Answer 2 $1,800 $Answer $Answer $1,600 $Answer 55.00% $Answer 3 $Answer...
For each of the scenarios below construct a decision chart (correct and incorrect decisions) similar to...
For each of the scenarios below construct a decision chart (correct and incorrect decisions) similar to Table 5-3 in the textbook, but be sure to explain what each decision means in terms of your scenario descriptions. In other words, you need to provide me more than simply Type I or Type II error in each cell of the matrix – spell it out in words – at least a sentence or two. a. A study working with premature infants to...
Discuss the short-run and long-run equity issues related to increasing the quality of education as opposed...
Discuss the short-run and long-run equity issues related to increasing the quality of education as opposed to the quantity. Students should be able to comment on the short run and long run effects on population growth, employment, growth, and welfare.
What are the characteristics of engineer-to-order products in manufacturing (as opposed to mass production)? Why are...
What are the characteristics of engineer-to-order products in manufacturing (as opposed to mass production)? Why are lead times significant for engineer-to-order products?   How does MES play a role in supporting manufacturing engineer-to-order products?
1. Update status for employee '100' to 'Temporary'. 2. Add a new attribute (field) status varchar(6)...
1. Update status for employee '100' to 'Temporary'. 2. Add a new attribute (field) status varchar(6) to the EMP table. 3. Using EXCEPT show the codes of the vendors who did not supply any products. The SQL Code: -- Creating Tables .headers on .mode column .separator , DROP TABLE IF EXISTS vendor; CREATE TABLE VENDOR ( V_CODE int, V_NAME varchar(15), V_CONTACT varchar(50), V_AREACODE varchar(3), V_PHONE varchar(8), V_STATE varchar(2), V_ORDER varchar(1) ); INSERT INTO VENDOR VALUES('21225','Bryson, Inc.','Smithson','615','223-3234','TN','Y'); INSERT INTO VENDOR VALUES('21226','SuperLoo,...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT