Double Sampling Plan for Defects Per Quantity Dialog Box

Double Sampling Plan for Defects Per Quantity Dialog Box

Used to enter the parameters of a double sampling plan for defects per quantity. Used to both specify a new plan and to edit an existing plan.

First Sample Size (n1): The first sample size must be a real number satisfying n1>0. It is not restricted to integer values. The first sample size can represent a length, area, volume or some other quantity of material to be inspected.

First Accept Number (a1): The first accept number must be an integer satisfying a1³0.

First Reject Number (r1): The first reject number must be an integer satisfying r1³a1+2.

Second Sample Size (n2): The second sample size must be a real number satisfying n2>0.

Second Accept Number (a2): The second accept number must an integer satisfying a2³r1-1.

Units: Units associated with sample sizes n1 and n2. Generally a length, area or volume.

Clicking the Show Advanced button also displays the following advance options:

Method of Curtailing: Generally curtailing of inspection is not performed.

Lot Size Option: Selecting all lot sizes will evaluate sampling plan based on Type-B OC curves (Poisson distribution) describing the worst-case protection the sampling plan will provide regardless of lot size. Selecting a specific lot size will evaluate the sampling plan based on Type-A OC curves (Binomial distribution) describing the protection for a specific lot size.

Lot Size (N): Used to enter lot size when specific lot size option is selected. Must be a real number satisfying N³n1+n2.

Clicking the Hide Advance button hides these last three options and resets them to the defaults of no curtailing, and all lot sizes.

When done, click the OK button or press the Enter key to save the sampling plan and close the dialog box. Clicking the Cancel button or pressing the Esc key cancels the changes to an existing sampling plan or the creation of a new sampling plan.

For a new plan, this dialog box is displayed by selecting the characteristic Defects Per Quantity and the type Double Sampling Plan from the ~~Enter New Sampling Plan~~ dialog box. To edit a plan, double click on it in the ~~List Sampling Plans~~ window.