In an industrial environment, quality control is critical for assuring that products comply with specifications and regulatory requirements. For precision machining operations, such as CNC turning at Merlo S.p.A., applying a sampling plan, rather than a full lot inspection, is an effective way to balance inspection needs with production costs and cycle times. However, the choice of the sampling plan directly impacts the risks tolerated by both producer and customer: on one side, the risk of rejecting good quality lots (producer’s risk α), and on the other, the risk of accepting bad quality ones (customer’s risk β). This thesis aims to compare different sampling plans, in particular, the company’s current plan (n=3, c=0), the ISO 2859 standard plans (single and double sampling), and a dynamic plan based on the process capability index Cpk, to identify the most effective strategy for reducing risks and ensuring outgoing quality.