The Continuous Sampling Plan for Two Production Lines: The CSP-2L

This paper presents the CSP-2L continuous sampling plan, which is designed for product inspectionon two independent production lines at the same time. The purpose of the CSP-2L is to improve the CSP-1-2Lin order to reduce the number of defective products that have passed without being inspected during thetemporary inspection stop, so the quality of the products is better. Therefore, if the manufacturer who uses theCSP-2L plan to inspect the production lines then resulting in higher quality of the products than the CSP-1-2L.This presentation includes the product inspection procedures and the formulas for performance measures suchas average total fraction inspected (ATFI), average total outgoing quality (ATOQ), and average total outgoingquality limit (ATOQL) which are carried out using a Markov chain. The formulas for performance measures ofthe CSP-2L have been tested to be accurate. When defined, the probability of a unit produced by the processbeing nonconforming of line 1 and line 2 are equal (p1 = p2 = p = 0.005, 0.015 and 0.035), the clearance numberof line 1 and line 2 are equal (i1 = i2 = 10, 20, 30, 40 and 50), the sampling fraction of line 1 and line 2 are equal(f1 = f2 =12and13) and the number of units to be found when inspection of line 1 and line 2 are in the phaseof sampling inspection at the same time (m = i1 and 2i1). Moreover, the ATOQ values from the CSP-2L and theCSP-1-2L plans were compared. The results showed that, the formulas for performance measures are accurateand in the case of p, the levels are low and moderate, the ATOQ of the CSP-2L are less than those of theCSP-1-2L in all cases. But in the case of p is at a high level, the ATOQ of the CSP-2L is less than those of theCSP-1-2L for some cases of i.