BOP Program Statement 2011.09 § 10

each Bureau payment site is too numerous to permit total review

without unduly burdening Bureau resources, a statistically valid

sampling of vouchers subject to the PPA will provide the basis

for reviews.

PS 2011.09

4/23/2003

Page 5

— The sample size will be determined using the compliance rate

from the previous QC Review. In addition, the Bureau uses a

confidence level of 90%, ± 5% precision. This means that if

the compliance rate is 85%, there is 90% confidence that the

percentage of on-time payments is between 80% and 90%.

The sample size computation will be included in the QC Review

working papers. The sample size for the first QC Review of each

new payment site will be determined using the table shown in

Attachment B.

— To determine the sample size for the first review, the RIC

will determine the number of payments subject to the Prompt

Payment Act made in the 12-month period being reviewed, N,

rounded to the nearest 100 (see Section 11).

— The RIC locates N on Attachment B and finds the

corresponding sample size, n. This is the number of

vouchers that must be reviewed during the first review.

Example: A payment site made 2,450 payments during the 12-months being reviewed. This would be rounded to N

= 2,500. Referring to Attachment B, it can be

determined that the sample size, n, is 131.

Sample sizes for subsequent reviews will be determined by using

the formula shown on Attachment C. A sample calculation is

included in Attachment C.

— Payment sites who achieve a 100% compliance rate of on-time

payments will use 99% as their compliance rate when

calculating the sample size for the next QC Review.

The RIC of the QC Review will compute the sample sizes using the

guidelines in Attachment B for the first review and Attachment C

for subsequent reviews. These sample sizes ensure reliable

results within established confidence levels without unduly

burdening Bureau resources.