This document represents a technical addition to the first report in Phase 2 of the Human Error in ATM' Project (HERA 2). It concerns the further development and investigation of human error, its prediction, detection and management within the Air Traffic Management (ATM) system. The purpose of the work is to assess how human errors are generated within a simulated ATM environment and, more importantly, how they are managed. This report describes in detail the tools and methods developed to record the error, and their recovery, made in the ATM environment.