4.3.1 Control leaves

Control leaf - the paper form on which in advance printed controlled parameters was it is possible it was possible to write down easily and precisely data of measurements. Its main appointment is double:

1) to facilitate data collection process;

2) automatically to order data for simplification of their further use.

Collecting and data recording at first sight seem easy business, actually it is quite difficult. Usually than more people process data, that a high probability of emergence of mistakes in the course of record. Therefore the control leaf on which it is possible to bring data with the help of marks or simple symbols and kotoryy1 allows to order automatically data without their subsequent copying by hand, - good means of data recording. It is given examples below.

Example.

Control leaf for registration of distribution of the measured parameter during production. Let's assume that we want to reveal change in razmakha of some detail which is exposed to machining, and the size specified in the drawing - 8,300±0,008. For receiving distribution of values of this indicator during process histograms are usually used. On the basis of the histogram average value and dispersion is calculated, it is investigated as well a distribution curve form. To construct the histogram, it is necessary to spend a lot of work for collecting a large number of data and for representation of frequency distribution in a graphic form. It is simpler to classify data at the time of collecting. In fig. 2.1 the form which can be prepared for this purpose in advance is shown. Every time when is made measurement, in the corresponding cage the cross is put, so hundred the histogram is ready to the end of measurements. If it is necessary to make stratification with use of one control leaf, it is better to take pencils of different color that a difference it was shown visually for marks.

	Deviation	Measurements																					frequency
		5 10 15 20
	-10
	-9
	-8
	-7
	-6
	-5																					1
	-4																					2
	-3																					4
	-2																					6
	-1																					9
8.300	0																					11
	1																					8
	2																					7
	3																					3
	4																					2
	5																					1
	6																					1
	7
	8
	9
	10
Итого																							55

- access field Border (according to the drawing)

Figure 2.1 the Control leaf for registration of distribution of parameter during production

Example.

Control leaf for registration of types of defects. In fig. 2.2 the control leaf used in the course of acceptance control of one stamped plastic detail is shown. Every time when the controller finds defect, it does in it a mark. At the end of the working day it can quickly count number and a kind of the found defects.

Simply the knowledge number of defects does not allow to make the decision on the correcting measures but if the leaf similar to it is used, it can give important information for process improvement as shows, what types of defects meet often, and what - no.

Using a similar control leaf, it is impossible to make then stratification of data, having broken them, for example, into morning and evening changes as it was possible in a case with the leaf presented in fig. 2.1. Therefore if stratification is necessary, when developing the form it needs to be provided in advance.

It is also necessary to provide how to register data in case the product contains two defects, and it is necessary to give instructions to people who mark products. In the case presented in fig. 2.2 defective were 42 products from 1525, but total number of the found defects - 62 as contained in some products on two or several defects.

Checklist

Product name

Дата:

Производственная операция, приемочный контроль

Участок

Тип дефекта: царапина, пропуск операции, трещина , неправильная обработка

Фамилия контролера

Общее число проконтролированных изделий: 1525

Номер партии

Применения по всем проконтролированным изделиям

Номер заказа

Тип дефекта	Результат контроля	Итоги по типам дефектов
Поверхностные царапины	/ /// //// //// //	17
Трещины	//// //// /	11
Пропуск операции	//// //// //// //// //// /	26
Неправильное исполнение операции	///	3
Другие	////	6
Итого		62
Общее число забракованных деталей		42

Figure 2.2 control leaf of types of defects