In enterprise application development the architectural decisions and rationale are rarely captured with the intention of reuse across proj ects. This implies that for new proj ects, the process of collecting requirements, user scenarios, high-level architecture, low-level design and the implementation proposal will be repeated with little reuse of such details from similar proj ects enterprise-wide. Rather, it would be much better if there is a structured, organized way to compile the knowledge and the rationale behind the decisions that were taken by the architect, hence paving the way to enable architecture knowledge reuse within in an organization. In this paper we introduce a method and system for documenting the architectural knowledge in a structured, unobtrusive, simple and efficient manner using office automation and web application technologies to enable automated architectural decision and rationale reuse through enterprise knowledge repository. We have also developed a prototype and presented snapshots of the same in this paper to demonstrate the effectiveness of our proposed approach.