The harness wire is a metallic circuit of wires connected through different circuitry components to function as per the design. harness wire differs from industry to industry as conditions differ: which includes, automotive, aircraft, and defense. All harness wiring involves connecting devices with copper wires to trigger pulses or pass power. Depending on the applications the protection level, concealing, insulations, and flexibility differ. Based on the requirements, I?ve classified harness wiring for different industries. Despite the sector, quality control and testing are essential for wire harnesses. Quality control involves inspecting the assembly to ensure that it meets the required specifications. This includes checking for any potential problems, such as loose connections or misaligned wires.