This Technical Bulletin outlines the performance standards for NSI-approved companies regarding routine (preventive) and corrective maintenance visits. It specifies that preventive maintenance visits should occur within a designated timeframe, with allowances for scheduling adjustments under certain conditions, and emphasizes the importance of maintaining access to premises for these visits. Additionally, it details the expectations for corrective maintenance response times and the consequences of failing to meet these standards, including potential non-compliance reporting by NSI. Manual review recommended for complete details.