Which of the following is NOT a type of spot check conducted?

Quality Control is indeed focused on evaluating the effectiveness of a maintenance process, but it is categorized differently than the types of spot checks outlined in the OPNAVINST 4790.1J. Spot checks are generally performed to ensure compliance with established standards and procedures, and typically consist of Historical, Maintenance Validation, and Monitored Maintenance checks.

Historical spot checks review past maintenance records to ensure that they comply with instructions and regulations. Maintenance Validation spot checks assess whether the maintenance was conducted properly and if the equipment is in a satisfactory condition. Monitored Maintenance spot checks are designed to observe personnel performing specific maintenance tasks to ensure adherence to prescribed policies and procedures.

In contrast, Quality Control serves as an overarching program to evaluate the overall efficiency and effectiveness of various maintenance processes rather than a method of spot checks themselves. Hence, identifying Quality Control as a type of spot check is not accurate, which clarifies why it is the correct choice for this question.