The distribution of lumber strength any grade may evolve, for example, due to climate change, forest fire, changes in processing methods, and other factors. So, North America the products industry monitors evolution their means, percentiles, or parameters ensure wood meet industrial standard. For administrative convenience informativeness, one adopt a rotating sampling plan by 36 mills initial ...

The mixed variables-attributes test plans for single acceptance sampling are proposed to protect “good lots” from attributes aspect and to optimize sample sizes from variables aspect. For the single and double mixed plans, exact formulas of the operating characteristic and average sample number are developed for the exponential distribution. Numerical illustrations show that the mixed sampling ...