Sampling Plans & Acceptance Sampling Flashcards

Consumer's risk (β) in acceptance sampling is the probability of:

Answer: Accepting a bad lot at the LTPD quality level

Consumer's risk (β) is the probability that a bad lot at the Lot Tolerance Percent Defective (LTPD) quality level is incorrectly accepted, representing the risk borne by the customer.

LTPD stands for:

Answer: Lot Tolerance Percent Defective

LTPD (Lot Tolerance Percent Defective) is the poorest quality level that a consumer is willing to accept in an individual lot, typically associated with a consumer's risk of 10%.

ANSI/ASQ Z1.9 provides acceptance sampling plans based on:

Answer: Variables data (actual measurements)

ANSI/ASQ Z1.9 uses variables (measurement) data to make accept/reject decisions, offering smaller sample sizes than its attributes counterpart Z1.4 for the same protection.

Rectifying inspection is a procedure in which:

Answer: All defective items in rejected lots are screened and replaced with conforming items

Rectifying inspection requires that rejected lots be 100% inspected and all defectives replaced with good items, which enables calculation of metrics like AOQL.

The Average Outgoing Quality Limit (AOQL) represents:

Answer: The maximum average outgoing quality over many lots with rectifying inspection

The AOQL is the worst average outgoing quality that will be passed to the consumer over the long run when rejected lots are rectified; it sets an upper bound on average outgoing defect levels.

Under ANSI/ASQ Z1.4, tightened inspection is initiated when:

Answer: Two out of five consecutive lots are rejected on original inspection under normal inspection

The switching rule to tightened inspection is triggered when 2 out of 5 consecutive lots are rejected on original inspection while on normal inspection, indicating a deteriorating process.

Under ANSI/ASQ Z1.4, reduced inspection may be considered when:

Answer: Ten consecutive lots have been accepted under normal inspection with a satisfactory production record

Reduced inspection requires 10 consecutive lots accepted under normal inspection, a satisfactory production record, and approval from the responsible authority before switching.