What Is a Pareto Diagram?

Pareto chart (Pareto chart) is a chart used to arrange the quality problems and quality improvement items in order of importance. Named after the Italian economist V. Pareto. Pareto chart, also called permutation chart, primary and secondary chart, is a histogram drawn in order of frequency of occurrence, indicating how many results are caused by the identified type or category.

Pareto chart

Pareto charts can be used to analyze quality problems and determine the main factors that cause quality problems. The purpose of ranking is to guide how to take corrective action: the project team should first take action to correct the problem that caused the largest number of defects. Conceptually, a Pareto graph is related to

Pareto Optimality, also known as Pareto efficiency and Pareto improvement, is an important concept in game theory and has a wide range of applications in economics, engineering, and social sciences.

Pareto optimality is a kind of resource allocation

To organize and optimize data from highest to lowest.

A statistical analysis method used to identify the few factors that are consuming the most resources.

1. List all content of interest

2. Measure elements, each element uses the same unit of measurement

3. The content of the command is based on your own measurement

4. Percent calculates the total measurement of each element

5. Cumulative percentage equals 100% from top to bottom

6. Create a block and circuit diagram with the circuit as a cumulative percentage

7. Prior work on the most important components

Step 1 data collection

For the collection of data on problems such as defects, disasters, and errors found during the data collection period, we can determine the period of the data set according to the status and nature of the problem. The cycle can also be collected weekly according to the specific situation of the problem.

Step 2 classify the data according to the reason and content

· Causes can be classified by material, machine, operator, and method of operation

Content can be classified by bad items, places, and time

Step 3 Organize the data according to the classification items and make a calculation table

The classification items are arranged according to the amount of data, and the "other" items are ranked last regardless of their size.

Step 4 Make the vertical and horizontal axes in the chart

The vertical and horizontal axes are preferably the same length, and the interval between the scales is appropriately determined

Vertical axis: The end point of the coordinates should be slightly larger than the total number of data, and it should be selected appropriately (rounded up)

Horizontal axis: arranged from left to right according to the data of the item, and enter the corresponding item name below

· The vertical axis is characteristic values such as number of records and amount; the horizontal axis records classification items

Step 5 Make the histogram

The "Other" item in the histogram is placed at the far right, with no gaps between the items. The "other" item, regardless of its size, should be placed at the far right as the last item and as the object of review

Step 6 making the cumulative curve

The accumulated value is a dot on the upper right of each histogram, and then these points are connected by a straight line to make a polyline. The starting point of the polyline is 0. The polyline is the cumulative curve of the Pareto chart

Step 7 Preparation of Cumulative Ratio

Make the vertical axis on the right side of the Pareto chart, and establish the starting point (0) and end point (100%) of the right vertical axis corresponding to the left axis. Divide the length from 0-100% and record the scale, for example : 20% can be divided into five equal parts, and 10% can be divided into ten equal parts. And even if the total value of the data ratio exceeds 100% (100.1% cumulative, rounding reasons), the vertical axis is still recorded at 100%.

Determination of the end point (100%): the horizontal parallel line (that is perpendicular to the left vertical axis) is drawn from the data count points on the left vertical axis, which must intersect the left vertical axis, that is, the intersection point is on the right vertical axis 100% point data round-off decision: "five rounds down, five rounds up, whole five even rounds up odd", that is, the principle of rounding down to 4 and rounding up to 6 and 1. The number is five o'clock. However, if it is an even number, it is rounded off, and if it is an odd number, it is rounded up.

Example: 10.26 10.3 10.24 10.2

10.25 10.2 10.15 10.2

Step 8 Enter necessary items

(1) Pareto chart title is entered in the lower part of the chart

(2) Collection time of data recorded

(3) the total value of the data entered;

Example: Number of pieces n =; Amount = Yuan

(4) Date of completion