In light of the popularity of digital documents in manufacturing systems and manufacturing support systems, implementation of electronic solutions for enterprise document management is critical for modern enterprises to effectively accumulate domain knowledge. Previously, automatic document classification mechanisms were developed to reduce the human efforts dedicated to document classification. However, these approaches simply focused on single-level document classification and could not exactly meet the organization operation requirements. Due to the complexity of enterprise processes, products, and services, a multilevel document classification methodology for enterprise documents is explored in this research. A silicon intellectual property (SIP) management case is also provided to evaluate the performance of the proposed methodology in the realization of intelligent knowledge management.