Histogram:
Histograms are usually used to present "continuous data", that is data that represents measured quantity where, at least in theory, the numbers can take on any value in a certain range. A good example is weight. If you measure the weights of a group of adults you might get and numbers between say 90 pounds and 240 pounds. The data would then be collected into categories (buckets/bins) to present a histogram. For example:
might be a histogram for weights (with the appropriate scale on the
vertical axis). Here the data has been collected into categories of
width 30 pounds.
Usage of histogram:
Histogram in context of “Plan Quality” and “Control Quality”
When Histogram is used in “Plan Quality”, it serves as a preventive approach to improve processes where historical data is used to identify categories of causes effecting most. Processes are selected to improve E.g. we may select improvements in “Collect Requirement”, “Define Scope” processes.
When Histogram is used in “Control Quality” it serves to identify causes of poor performance in process and work products.
Difference between Pareto Chart and Histogram:
Histograms are usually used to present "continuous data", that is data that represents measured quantity where, at least in theory, the numbers can take on any value in a certain range. A good example is weight. If you measure the weights of a group of adults you might get and numbers between say 90 pounds and 240 pounds. The data would then be collected into categories (buckets/bins) to present a histogram. For example:
Usage of histogram:
Histogram in context of “Plan Quality” and “Control Quality”
When Histogram is used in “Plan Quality”, it serves as a preventive approach to improve processes where historical data is used to identify categories of causes effecting most. Processes are selected to improve E.g. we may select improvements in “Collect Requirement”, “Define Scope” processes.
When Histogram is used in “Control Quality” it serves to identify causes of poor performance in process and work products.
Difference between Pareto Chart and Histogram:
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| Histogram | Pareto Chart |
| Histogram is a kind of bar chart showing a distribution of continuous variables or causes of problems. | A Pareto chart is a specific type of histogram that represents causes of problems by their overall influence. This is an effective tool to prioritise corrective action as errors with greatest impact are displayed in descending order of frequency. |
| A histogram represents cause of a problem as a column and the frequency of each cause of problem as the height of the column. | In addition an arc representing the cumulative percentage of frequencies of causes is also included. |
In short, A histogram is a bar chart that show the frequency of a cause of a problem occurring using the height of the bar as an indicator.
