This community service program aims to improve the understanding and skills of students and teachers at SMK Bintang Nusantara regarding expert systems through socialization, practical workshops, and training. The program was motivated by students' low basic knowledge and practical experience of expert systems, as well as teachers' limited capacity to deliver applicable information technology materials. The program was implemented using the Experiential Learning approach through an initial needs survey, module development, theory sessions, hands-on prototyping of expert systems using open-source software (ES-Builder) with a computer hardware damage diagnosis case study, and mentoring. Evaluation was conducted through pre-test, post-test, project assessment, and satisfaction questionnaires involving 30 participants (25 students and 5 teachers). The results showed a significant increase in participants' average comprehension scores from 45.2 (pre-test) to 82.7 (post-test), with a gain score of 83%. Eighty percent of participant groups successfully built functional expert system prototypes, and 85% of grade XII students expressed interest in using the expert systems theme for their Competency Test (UKK) projects. The program also produced a reusable teaching module and enhanced teachers' capacity to integrate rule-based artificial intelligence materials into the curriculum. Thus, this program contributes to narrowing the technology competency gap between vocational school graduates and the needs of the business and industrial sectors (DUDI).