High-tech firms face constant innovation and challenges due to a rapidly changing tech environment. Open innovation strategies are an important solution for fostering rapid and efficient innovation by leveraging external capabilities. This study explores the critical factors that influence open innovation strategies in high-tech companies, assessing their importance and providing key insights for promoting these strategies. Through a comprehensive literature review and expert interviews, 16 key factors impacting open innovation were identified. A hierarchical research model was developed using the ser-M (subject, environment, resource, mechanism) framework, focusing on subject, environment, resource, and mechanism for a corporate strategy analysis. A survey and an AHP analysis were conducted with 30 participants, comprising engineers and open innovation experts, all with over a decade of experience in the field within Korean high-tech companies. The analysis focused on four critical elements: subject, environment, resource, and mechanism; subject emerged as the most critical factor for successfully implementing open innovation strategies. Specifically, the will of chief executives, the direction of decision-making, and technological environment changes were found to be significant contributors. The consensus between engineers and experts confirms that while environmental and resource factors are vital, strong leadership and effective decision-making are paramount for successful open innovation in high-tech companies.