The MIL-STD-414 application has been vastly improved. You can now design plans for both known and unknown variability, and the application has been completed to include all three types of inspections. Give it a shot!
This application designs a sampling plan for variables, according to the Military Standard 414 tables (ANSI/ASQ Z1.9, BS6002, ISO 3951) tables, for a given lot size and AQL. It also calculates the estimated percent defectives in a lot, given the known or estimated variability.
More about acceptance sampling plans.