<![CDATA[oriented towards circuit assembly and operation, thus not optimal in developing students' ability to systematically diagnose and resolve technical issues. This research aims to develop an electropneumatic media trainer-based simulation method and test its validity, practicality, and effectiveness in enhancing the Problem Solving Skills (PSS) of VHS students. The research employs a Research and Development (R&D) approach with the ADDIE model, including Analysis, Design, Development, Implementation, and Evaluation. The effectiveness testing applies a quasi-experimental method with a nonequivalent control group design, involving 72 VHS students from Negeri 2 Sungai Penuh, divided into an experimental group (36 students) and a control group (36 students). Data were collected through observation, interviews, need assessment questionnaires, expert validation, practicality questionnaires, and scenario-based fault scenario PSS tests. Data analysis was conducted descriptively and inferentially using feasibility percentages, normalized gain (N-gain), and Mann–Whitney U tests. The research results yielded a simulation method integrating five learning stages, ten fault scenarios, and systematic troubleshooting procedures. Expert material validation obtained a score of 93.61% and media expert validation 93.33%, both categorized as highly valid. Practicality based on teacher assessments reached 93.64% and student assessments 91.62%, both categorized as highly practical. Testing effectiveness shows an average PSS score increase of 10.33 points with N-gain 0.713 (high category), while the control group increased by 4.25 points with N-gain 0.163 (low category). The Mann–Whitney U test indicates a significant difference in the second posttest results of the two groups (p < 0.001). This finding suggests that the integration of simulation methods, electro-pneumatic trainers, and systematic troubleshooting is effective in enhancing problem-solving skills through structured fault diagnosis experience. Thus, the developed method meets the criteria of valid, practical, and effective as an alternative for Industrial Control System learning in SMKs. Further research is recommended to test its application on more schools with various disruption scenarios to expand the generalizability of the findings.]]>
