To ensure the comprehensiveness and professionalism of internal audit work, an audit team led by management representatives and composed of key personnel from various departments, based on the ISO9001:2015&IATF16949:2016 quality management system standards, clarifies the audit process, judgment criteria, and work discipline. Through a four-dimensional investigation method of on-site verification, data review, personnel interviews, and process walkthrough testing, a total of 320 business records were randomly checked, 18 key locations such as production workshops and R&D laboratories were visited, and 36 employees from various positions were interviewed. The focus was on conducting in-depth reviews around core dimensions such as process compliance, clarity of responsibilities, effectiveness of execution, and risk prevention and control capabilities. Finally, various problems such as poor process connection, non-standard form filling, untimely updates of some systems, and cross departmental collaboration barriers were identified, and a detailed audit report containing problem descriptions, risk levels, and rectification suggestions was formed, which pointed out the direction for subsequent improvement work.

In response to the problems identified during the internal audit, the company immediately held a rectification promotion meeting and established a closed-loop management mechanism of "problem number responsible department rectification measures completion deadline verifier", clarifying the rectification responsibilities and time nodes for each problem. Each department responded quickly and developed targeted improvement plans based on their own business realities: the production management course optimized the planning process and integrated customer orders to improve production efficiency; The engineering course has improved the technical document management standards and solved the problem of untimely cross team data sharing; Optimize the procurement process, integrate resources, and improve work efficiency in the procurement course; The administrative personnel course will optimize the training system, improve the training content, and increase specialized training on job skills. During the rectification process, the audit team conducted follow-up verification to ensure that all improvement measures were implemented effectively. A total of 12 process optimizations, 26 system revisions, and a 100% problem rectification rate were completed.

Through the full process closed-loop management of "review rectification review optimization", we have not only achieved a systematic upgrade of the institutional system and refined improvement of operational norms, but also promoted the synchronous improvement of work efficiency and employee experience, laying a solid foundation and execution guarantee for the high-quality development of the company.