When assessing a median-sized factory, prioritize their R&D depth and equipment precision. You should verify if they utilize CNC machining, automated assembly lines, or specialized testing labs. Request a technical capability profile that includes their patents, software compatibility (e.g., AutoCAD, SolidWorks), and their ability to handle OEM/ODM customizations. A reliable factory should demonstrate a defect rate below 1-2% through documented Internal Quality Control (IQC, IPQC, OQC) processes.