This card, invoked by button “variables and attributes” on the General tab Control Planning, allows you to define aspects to be monitored and their respective control parameters.
The table at the top left is the same as calling all aspects to be tested for the product in question, in any type of test.Every aspect about testing is identified by a serial number and test criteria defined on this tab apply to the currently selected appears.
DEFINITION OF TEST APPEARANCE
Next to the table there are some General data needed for a more detailed definition of the aspect at issue:
- Identification of the appearance as a variable or as an attribute:
- We talk about Attribute when the verification is conformity or not only with respect to the parameters data (positive or negative feedback); are freely definable parameters (separated by semicolons, as in the example) the following section; during the recording of the tests will show the drop-down list containing those values:
- It is Variable, however, when the control is necessary to detect the measures; the finding in this case is not simply positive or negative, but it’s a comparison against benchmarks set. To this end, the program presents a section measuring values.
- in Nominal,type in Nominal value;
- in the Minimum box, type the minimum value, below which the measure cannot be accepted; automatically calculates the value of the lower tolerance (Inf.Toll.);
- in the Maximum box, type the maximum value, above which the measure cannot be accepted; the program calculates automatically the upper tolerance value (Sup.Toll.);
- Finally specify the unit of measurement in the field.
- The Number of the variable concerned;
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his Description full (maximum 30 characters);
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his qualitative characterization, i.e. the specification if it is a variable Criticism, Important or Secondary .
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The Area of employment i.e. the production cycle time (acceptance, process, final testing), to testing of the variable in question; in particular, if the area of application will be the process, turns on other fields: the field work Phase, in which shall be indicated the specific phase in which it will be carried out in variable control object and, in the below section on statistical testing/non-statistical, fields in which should be further specified when the phase is the control of the variable and any number of units (or minutes).
SAMPLING TYPE
After completing General data about each variable or attribute you want to test, for each of them should be set sampling, which can be:
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ISO2859-1: on the basis of statistical standard ISO2859/1 (or Military Standard 105), which requires the definition of a number of parameters (test level, type of sampling, test type, L.Q.A.), which, combined with the lot size, give the size of the sample to be tested and the relative limits of acceptability.
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Not-statistical based on an a priori definition of the size of the sample, which can be done in two ways: a) using fixed size, with a fixed number of acceptance and a fixed number of rejection or b) using the percentage of the lot size.
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Not Statistical percent.
STATISTICAL sampling (according to ISO 2859/1)
Press the ISO2859/1: instantly open the following fields:
- Specify the testing’s level , the sampling’s plan, and the test’s type;
- indicate the L.Q.A. (acceptable quality Level), by selecting the corresponding value;
- tick alternately or % of not conform (if one considers the L.Q.A. as a percentage of non-conforming units) or Defects for 100 units (if one considers the L.Q.A. as the total number of defects per 100 units).
NON-STATISTICAL sampling
Press:Not statistical opens the following fields:
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Specify the Dim of Sample A, i.e. the number of units that form the sample with which you begin testing.
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Specify the Dim of Sample B, i.e. the number of units that form an alternative standard, which can occur after a certain number of lots tested without non-compliance. This of course will consist of a number of units below the first, having the purpose to simplify testing. The sample B may even be of 0 units, when non-means test that aspect if a number of tests had failed to conform.
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Specify for each sample a number of acceptance (N.A.) which is the maximum number of non-compliances to be tolerable considering the variable or attribute as “conform”.
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a number of rejection (N.R.), i.e. the number of non-compliance from which the variable/attribute is considered “Not Compliance” .
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In the number of conform lots for the passage A-B indicate the number of subsequent lots on which testing must have given positive results, in order to go to sample B.
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If you choose to set a policy of spot testing (tick the appropriate box), you activate the field “a lot every“: indicate how many lots should be done every test.
Note in this case, you will disable the B sample fields and the number of lots in accordance with the A-B.
NON-STATISTICAL PERCENTAGE sampling
Sometimes it may be necessary to give the sample size as a percentage of the lot size. In this case press “Not statistical percentage”:
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There are similar to those of the non-statistical sampling, but expressed in units, but not as a percentage: the Perc. of sample A, the Perc. B sample , and the respective percentages of acceptance (% A.) and rejection (% R. ).
N.B. If you want to have a rejected number equal to 1, you must enter a percentage equal to 0.0001 which, even if lot number high, returns a number less than 1 the program rounds up to 1. -
Specify the number of conform lots for the passage A-B, according to the same criteria given for the Non-statistical sampling.
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Even in this case, you can set a spot testing, indicating even here every how many lotes run.
GENERAL METHODS OF TEST EXECUTION
After compiling the most specification for testing criteria, there are other data that contains reference information for the practical application of the above-mentioned parameters.
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In the field Business Unit Validity, specify whether the testing Plan defined for the variable in question applies to all suppliers of the article or only for some.
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In the field Type of checking tool indicate the category of the tool with which the test must be carried out.
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In the Reference’s Documentation, draw any documentation to which you must move in the test execution (drawings, specifications, samples, etc.)
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In the Procedure, it is possible to describe in detail the test procedure. For long texts, for which need a lot of space, you can facilitate the writing and reading, press with your mouse the blue arrow in the upper right corner of the Notes field: this field will extend across the screen; to return to normal size, just click with your mouse the blue arrow in the lower right corner.
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Finally, Intervention in case of N.C. , you can report the interventions adopted in case test phase have expressed N.C. Also applies here above for enlarging and reducing the box.
If the article has a reference to a test Plan template, there is a tab “variables/Attributes model” that allows you to customize attributes or variables in the template:Pressing it you get the list and, once you have chosen the variable or attribute you want to customize, this is copied to the local testing plan at the article. Within the control, therefore, with the same variable or attribute number between local plan and model plan, the first shall prevail.