## 3 Framework of Forecasting AOG Models in Aviation  
### Overview and Definition of AOG in Aviation Industry  
AOG refers to an airplane that cannot fly due to technical issues, often requiring urgent maintenance, parts replacement, or repair. In other words, it means a loss of operational capacity and can have significant financial implications for airlines and associated stakeholders. According to IATA, delays and disruptions caused by AOG events can lead to substantial operational costs, impacting revenue and customer satisfaction [13]. The fault rectification flowchart (Figure 1), designed for maintenance failures, is an overview of the course of action relating to an aircraft with technical problems. The first part of the chart illustrates the situation when an issue occurs and good-conditioned spare parts are available. Local rectification follows for a particular scenario. The second part of the flowchart describes the step-by-step actions that shall be taken to return the aircraft to service in case of AOG. The initial phase involves identifying that the fault cannot be rectified locally. At this stage, the problem is confirmed in the MEL Defect category, which involves the Integrated Operations Control Centre (IOCC) receiving the immediate report. The IOCC controls and secures high-impact aircraft operations and regulatory compliance. The primary aim of the IOCC is event response coordination, which involves the team making up the immediate report, as well as urgently deciding which operating aircraft should be alive and ensuring compliance with the established safety standards. The next step includes the Analysis of Deviation along with the decision-making capability. This stage entailed the engineering teams performing inspections and tests to identify the fault, utilizing diagnostic tools and historical data. This step is a significant factor that detects the root cause of the problem and the goals, thereby defining the solution with the help of safety and regulatory authorities. The following phase of the process is rectifying possibilities by the team through intensive troubleshooting work. This phase is often a circular process with the involvement of suppliers or maintenance organizations from the \"outside\". Troubleshooting in the industry is required to keep in check the air traffic technicians; thus, Civil Aviation Authorities standards rank as the topmost consideration. The long-awaited resolution of the difficulties follows with the definition of the Rectification Options executed by the Maintenance Control Center (MCC). At this stage, the emphasis is on the prompt availability of parts, resources, and skilled craft people. This phase requires strictly following the guidelines on maintenance and documentation as mandated by aviation regulatory bodies. The last phase, which involves the preparation of the follow-up documentation, monitors such actions to guarantee that Airworthiness Certificates are issued. This makes it a legal requirement that everybody follows the aviation rules, which include keeping the operation safe and certifying it. AOG Management Procedures  
According to the guidelines from the ICAO, aviation companies ought to have comprehensive reporting systems in place so that AOG events can be documented in real-time data [14]. In the event of an AOG detection, airlines start a phased response process, which usually includes the following actions:  
- Issue Assessment;  
- Parts Procurement;  
- Repair and Maintenance;  
- Quality Control;  
- Return to Service. The primary stakeholders are to be informed after the quality assurance check is passed and the aircraft returns to service. How Is AOG Managed with Technology? The arising technological era has initiated a new era for the management of AOG. The use of real-time monitoring systems such as the Vehicle Health Monitoring System (VHMS) that enable airlines to apprehend potential technical ahead of their evolution to an AOG event is amongst the benefits associated with such technologies.