Six, Histogram A histogram is a value for the characteristics of a product or process, the use of normal distribution (also known as the normal distribution) principle, the 50 or more data packets, and calculates the number of each group appears, then similar histogram shape plotted on the horizontal axis. 1, the implementation of step 1) to collect the same type of data; 2) Calculation Range (full-pitch) R = Xmax-Xmin; 3) set the number of groups K: K = 1 + 3.23logN data Total 50 100 to 250 250 to 100 above group having 6 to 10 7 to 12 10 to 20 4) Determine the smallest unit of measurement that the number of decimal places to n, the minimum unit is 10-n; 5) Computing Group from h, groups from poor h = R / group Number of K; 6) is obtained on each group, the lower limit of the first set lower limit value = X ?? min- measure the minimum unit 10-n / 2 second set lower limit value (first set upper limit value) = The first group from the lower limit value + group h; 7) to calculate the central value of each group, set the center value = (lower limit + group set an upper limit) / 2; 8) Make a frequency table; 9) according to the frequency table Videos histogram. 2, the common form of the histogram and determine 1) the normal type: is normal QC seven practices, subject to statistical laws, the process is normal; 2) the missing tooth: not normally distributed, the statistics do not obey the law; 3) skewness Type: not normally distributed, do not obey the statistical laws; 4) Islands type: not normally distributed, the statistics do not obey the law; 5) Plateau: not normally distributed, the statistics do not obey the law; 6) bimodal: not positive state distribution, disobedience statistical law; 7) irregular: not normally distributed, the statistics do not obey the law. Primarily as a record or check use. Data stratification (Data Stratification) data stratification, also known as stratification method is the same nature, the data collected under the same conditions are summarized together for comparative analysis. Because the factors, the actual production QC seven practices of training Which is strong, changes affecting the quality of many, if not to distinguish between these factors, it is difficult to draw the law change. Data stratification can be a variety of ways according to the actual situation. Such as Dongguan QC seven practices, according to different time, different shifts were stratified according to the type of equipment used to stratify by feeding time of raw materials, according to the raw material components were stratified by means of inspection, stratified according to the conditions of use , stratified according to different defect items, and so on. Data stratification method often used in conjunction with the above statistical analysis table. Application data stratification, the main concept is a system that is to be treated fairly complex information, you have to know how to put this information in a systematic and purposeful to be categorized and summarized statistics. Based management emphasizes scientific management techniques, to make up for past deficiencies on experience, relying on visual judgment of management. And this management techniques, in addition to establishing the right idea, but also the need to use data only way to carry out the work of analysis and take corrective action. How to build the original data and the purpose of the data needed to be set on the basis of design, quality control is the most basic work of many practices. For example: China's aviation market in recent years, with an open and increasingly fierce competition in what is a QC seven practices, in addition to the airline to strengthen measures for the market, but also lay emphasis on quality of service. We can often see customer satisfaction survey in the aircraft. This survey was carried out through a questionnaire. Questionnaire design is usually divided into ground service quality service quality and on board an aircraft. Floor is divided into ticketing, waiting; aircraft is divided into flight attitude, food, and health. Through these surveys, these data will be disaggregate, can be enhanced where the quality of service. Enterprise Road (map), Guangdong QC seven practices, QC seven practices provided by enterprises in Huizhou City Road Enterprise Management Services Limited. Road Zhiyuan, temper forward. Huizhou City, the rate of the Road Enterprise Management Services Ltd. (isoew.com) aims to become and you win symbiosis, strategic partners to move forward, more determined to become the other's most influential business, and you leap together to success!