<p>Engineer-To-Order (ETO) industrial manufacturing increasingly requires automating highly customized product design amid significant technical and organizational complexity. However, traditional combinations of rule-based Expert Systems and CAD automation tools often fall short when product design involves order-specific optimization problems and when exact component configurations cannot be fully predefined. Simultaneously, project implementation in such environments is frequently hindered by critical failure factors related to communication, knowledge transfer, human resources, and planning. This study introduces a Hybrid Design Automation System that combines a rule-based Expert System, algorithmic optimization modules, and a custom CAD application based on the Automatic Assembly Synthesis Model. Additionally, the study employs a heterarchical project management approach to overcome organizational barriers during implementation through self-organization, self-regulation, and Soft-OR communication tools. The practicality of the proposed approach is demonstrated through an industrial case involving the customized design of an aluminum elevator shaft product family. The case illustrates significant reductions in engineering study time and order lead time, rapid optimization runtimes, and expanded order coverage for the key product category. The findings indicate that successful design automation in ETO environments depends on the integrated alignment of computational and coordination architectures.</p> Graphical abstract <p>HyDAS Project Implementation Framework</p> <p></p>