Big data and instant information on the external environment of enterprises are critical for decision-making; however, little attention is paid to contemporary business intelligence (BI) theories and practices. This study proposes a new business decision model, agile BI (ABI), which integrates external big data and internal BI to facilitate decision-making for enterprises in a dynamic and rapidly changing environment. This novel model presents two contributions to research in this field: (1) it proposes a new architecture combining external and internal information and (2) it integrates external big data, such as hot searches, social media, news, popular issues, and competitors' information, to increase the accuracy of BI. This study takes international expansion as an example and simulates the international investment decisions of Taiwanese firms by importing data from a search engine, competitors, and firm-specific datasets. The results show that the proposed ABI model not only responds quickly to the external environment but also enhances decision-making efficiently.