Developing and economic design of variables modified double sampling plan

The design of a modified double sampling plan is investigated in this manuscript for the inspection of measurable quality characteristics under single specification limit. The optimal plan parameters of the suggested variables modified double sampling plan for known and unknown sigma have been identified by satisfying the risks of the producer and the consumer at their respective quality levels. The most suitable plan parameters are identified by formulating a nonlinear optimization problem, which minimizes the average sample number. The main goal of developing the proposed variables sampling plan is to reduce the average sample number with safeguarding both producers and consumers. Merits of the suggested variables modified double sampling plan under single specification limit are discussed. An industrial example of the suggested sampling plan is explained. In addition, an economic aspect of design of the variables modified double sampling plan based on single specification limit is investigated.