Modern technology is developing faster than we think. In industry 4.0, hundreds of new products are launched daily, but the assembly unit back-end process is tedious. Product and assembly process complexity are proportional. After manufacturing, assembling workers finish the product. User manuals and technical documentation take longer and complicate simple procedures. They may be outdated. From smartphones to heavy equipment, every new product needs assembly instructions. Industry can use Augmented Reality. Product assembly using AR makes production easier. AR can guide assembly operators and trainers using computer graphics, text, and sound. This enhances productivity and reduces time. Assembling products quickly and accurately reduces complexity.