@inproceedings{shin-etal-2025-multidocfusion,
    title = "{M}ulti{D}oc{F}usion : Hierarchical and Multimodal Chunking Pipeline for Enhanced {RAG} on Long Industrial Documents",
    author = "Shin, Joongmin  and
      Park, Chanjun  and
      Park, Jeongbae  and
      Seo, Jaehyung  and
      Lim, Heuiseok",
    editor = "Christodoulopoulos, Christos  and
      Chakraborty, Tanmoy  and
      Rose, Carolyn  and
      Peng, Violet",
    booktitle = "Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing",
    month = nov,
    year = "2025",
    address = "Suzhou, China",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1062/",
    pages = "20996--21015",
    ISBN = "979-8-89176-332-6",
    abstract = "RAG-based QA has emerged as a powerful method for processing long industrial documents. However, conventional text chunking approaches often neglect complex and long industrial document structures, causing information loss and reduced answer quality. To address this, we introduce \textbf{MultiDocFusion}, a multimodal chunking pipeline that integrates: (i) detection of document regions using vision-based document parsing, (ii) text extraction from these regions via OCR, (iii) reconstruction of document structure into a hierarchical tree using large language model (LLM)-based document section hierarchical parsing (DSHP-LLM), and (iv) construction of hierarchical chunks through DFS-based grouping. Extensive experiments across industrial benchmarks demonstrate that \textbf{MultiDocFusion} improves retrieval precision by 8{--}15{\%} and ANLS QA scores by 2{--}3{\%} compared to baselines, emphasizing the critical role of explicitly leveraging document hierarchy for multimodal document-based QA. These significant performance gains underscore the necessity of structure-aware chunking in enhancing the fidelity of RAG-based QA systems."
}