Named Entity Recognition (NER) in the tender and procurement domain is critical for tasks such as contract monitoring, supplier analysis, and compliance tracking. However, unlike general-purpose NER, no open-source datasets exist for Tender NER, largely due to data sensitivity and confidentiality restrictions. This scarcity limits the development of automated entity extraction models. To address this gap, we propose struct2unstruct, a data preparation pipeline that generates and annotates tender-specific datasets using large language models (LLMs). Starting from structured procurement data published by the Singapore government (2015–2021) available in English language, we employ Llama-3 to generate synthetic tender narratives in multiple writing styles, ensuring each contains at least one tender-related entity. Post-processing steps correct inconsistencies in dates, symbols, and entity formats. Entities are then annotated using a BIO tagging scheme through deterministic alignment with structured fields, followed by expert validation to ensure accuracy. This study focuses on data preparation and evaluation, not model training. The resulting dataset provides a scalable resource for future Tender NER research in low-resource environments. By releasing both the dataset and pipeline as open-source resources, we establish a foundation for advancing domain-adapted information extraction and automated tender entity recognition.

Extracting structured text from complex tables in PDF tender documents remains a challenging task due to the loss of structural and positional information during the extraction process. AI-based models often require extensive training data, making development from scratch both tedious and time-consuming. Our research focuses on identifying tender entities in complex table formats within PDF documents. To address this, we propose a novel approach utilizing few-shot learning with large language models (LLMs) to restore the structure of extracted text. Additionally, handcrafted rules and regular expressions are employed for precise entity classification. To evaluate the robustness of LLMs with few-shot learning, we employ data-shuffling techniques. Our experiments show that current text extraction tools fail to deliver satisfactory results for complex table structures. However, the few-shot learning approach significantly enhances the structural integrity of extracted data and improves the accuracy of tender entity identification.

In the public procurement domain, extracting accurate tender entities from unstructured text remains a critical, less explored challenge, because tender data is highly sensitive and confidential, and not available openly. Previously, state-of-the-art NLP models were developed for this task; however developing an NER model from scratch required huge amounts of data and resources. Similarly, performing fine-tuning of a transformer-based model like BERT requires training data, as a result posing challenges in training data cost, model generalization, and data privacy. To address these challenges, an emerging LLM such as GPT-4 in a Few-shot learning environment achieves SOTA performance comparable to fine-tuned models. However, being dependent on the closed-source commercial LLMs involves high cost and privacy concerns. In this study, we have investigated open-source LLMs like Mistral and LLAMA-3, focusing on the tender domain for the NER tasks on local consumer-grade CPUs in three different environments: Zero-shot, One-shot, and Few-shot learning. The motivation is to efficiently lessen costs compared to a cloud solution while preserving accuracy and data privacy. Similarly, we have utilized two datasets open-source from Singapore and closed-source commercially sensitive data provided by Siemens. As a result, all the open-source LLMs achieve above 85% F1-score on an open-source dataset and above 90% F1-score on a closed-source dataset.