Managing product variability in digital assembly instructions

The trends of mass customization and personalized production lead to increased manufacturing complexity, requiring human involvement for flexibility, particularly in High-Mix, Low-Volume (HMLV) assembly. These production systems impose challenges on operators, highlighting the growing importance of providing cognitive support. Digital assembly instructions have emerged as a solution, offering step-by-step guidance to operators. However, creating and maintaining these instructions is labor-intensive, especially in HMLV contexts, due to numerous product variants and frequent design changes. This study introduces a framework for integrating product variability in digital assembly instructions and streamlining the instruction authoring process. A semantic model based on the industrial standard ISA-95 is proposed to integrate engineering information into assembly instructions. Additionally, a methodology is presented that incorporates a 150% workflow for managing instructions for a product family, from which specific variant configurations can be derived. The system suggests relevant instruction content during the authoring process of a new product variant to enhance the reuse of previously written instructions. A methodology to handle engineering changes within the assembly instructions has also been developed to warrant consistency with the product design. Initial testing has demonstrated promising results, including substantial time savings and improved consistency.