Exploring association rules overseeing subcontractor quotation behaviors: an empirical study in the construction industry of Taiwan

Two construction contractual parties enter negotiations to delineate terms and specifics, each aiming to negotiate the quotation to agree on a contract. The research objective is to delineate association rules overseeing subcontractors’ pricing behaviors. Through a comprehensive approach encompassing literature review and expert interviews, this study derives the attributes of quotation behaviors that inform the data collection process. The dataset encompasses information from nine significant engineering categories representing typical construction projects, featuring six quotation behavior characteristics. A total of 10433 quotations sourced from private sector endeavors over the past 10 years have been analyzed. Employing the Apriori algorithm, each engineering category yields between 2 and 5 association rules. A prevailing finding suggests that subcontractors across all sub-work types typically provide discounts of less than 10%, while their profit margins remain relatively stable across different work packages. The frequency of quotations shows considerable variability based on procurement quantity.