How do prescriptive and performancebased safety management system (SMS) requirements differ?

Marino Tudor: The recent International Civil Aviation Organization (ICAO) and European Aviation Safety Agency (EASA) safety rules for aerodromes have introduced performance-based regulations in addition to the traditional prescriptive requirements. In contrast to prescriptive rules, which explicitly define what must be done and how, a performance-based regulation approach is defined in terms of the desired outcomes.

Meeting prescriptive regulation is a straightforward process: an airport operator just needs to implement the requirement step by step without any deviation. Once the prescriptive requirement has been met, the organisation remains compliant until regulations change.

Meeting performance-based regulation is complicated because it is a dynamic process of collecting actual outcome values and comparing them with desired targets. This is a continuing activity in which the level of compliance is challenged every day.

Phrases such as ‘compliance or performance-based SMS’, or ‘Is your SMS programme performing or prescriptive?’ have appeared in many recent articles, but are entirely misleading – they are introducing a dilemma that doesn’t exist. There is no compliance without a performance-based approach, and there is no performance-based regulation without elements of prescriptive requirements. In practice, regulations are rarely fully prescriptive or fully performance-based, but rather contain elements of both.

Why are performance-based SMS requirements so challenging?

The implementation of performance-based SMS requirements is an ongoing process and has been recognised by airport operators as a mandatory approach to meet current ICAO and EASA regulations. But the problem is that there is a lack of common understanding of what performance-based SMS means and how to implement it, especially with what, when, why and how to measure.

All service providers, for example, are required to establish an efficient and confidential safety reporting system. This is often misunderstood as a prescriptive-only requirement, by which developing an appropriate report form, and compiling a description of reporting processes and procedures in an SMS manual is sufficient in order to be compliant with regulation.

But without measuring outputs – in this case, the number, rate and risk level of safety reports – there is no evidence on the efficiency of the safety reporting system. The same discussion could be applied to many other regulatory requirements, such as change management, risk assessment, internal audits and safety controls – which, at first sight, seem to be prescriptive only – but actually contain prescriptive and performance-based elements.

Commonly seen bad practice occurs when performance-based SMS is reduced to simply counting incidents and accidents. This implementation has a number of deficiencies.

Firstly, the absence of accidents and a low number of serious incidents – even over a period of years – is not a reliable measure for stating that risks are being controlled, and that an adequate level of safety has been achieved.

This approach incorrectly assumes that all events have the same level of risk and is focused only on high frequency/ low-severity occurrences, where events that had the potential to escalate into high-severity consequences are completely neglected. Only measuring lagging indicators – and completely ignoring leading indicators – underestimates the importance of potential consequences and practical drift (deviation from baseline performance), resulting in poor data sets for predictive analyses and developing actionable insights

The proper implementation of performance-based SMS should include a comprehensive safety data collection and processing system, safety data analysis (trends, pattern recognition, rates and alerts calculation) and the definition of a safety performance indicator (lagging and leading). In addition, there should be the constant monitoring and measuring of safety performance – outcomes versus targets – and required actions should be identified based on measured performance.

How can GALIOT Aero help to elevate SMS from a prescriptive to a performance-based approach?

Collecting, processing, analysing and modelling safety data is a demanding task that cannot be performed without an adequate software tool. Because prescriptive elements are the foundation for all future performance-based approaches, GALIOT Aero explicitly implements the prescriptive parts of all ICAO and EASA regulation requirements, such as a reporting system, investigation workflow, hazard identification, risk assessment and mitigation, the management of change, safety documentation, responsibility and accountably, safety communication, record keeping, surveys, audit management and compliance monitoring.

GALIOT Aero occurrence reporting system is based on the European Co-ordination Centre for Accident and Incident Reporting Systems (ECCAIRS)’ format and underlying Aviation Data Reporting Program (ADREP) taxonomy, enabling direct, machine-to-machine occurrence data exchange with relevant authorities. In addition to the standard ICAO risk matrix, GALIOT Aero’s risk management module also implements a barrier-based approach – bow-tie methodology – for risk visualisation and the identification of safety-critical scenarios.

As well as the prescriptive part, GALIOT Aero contains framework for a performance-based SMS composed of safety data collection and analyses, live performance measurement and the monitoring of safety performance indicators.

Safety data used for performance management is collected from proactive and reactive safety activities, such as safety reporting, investigation, operations, audits, surveys, change management and safety meetings. A live performance measurement and monitoring system instantly analyses collected data against the number of operations and event risk classification (ERC), and compares computed data with predefined safety targets and alert values. The system monitors lagging and leading indicators that are compared against agreed targets defined as improvement percentages, and the cumulative number of occurrences or rate of occurrences normalised by the number of operations.

For each safety performance indicator, an alert level calculation – based on ICAO Doc 9859 – is performed instantly.

Performance-based safety management should not be adopted only to meet recent regulatory evidence-based requirements, but also to improve an organisation’s level of safety.