The Implementation Concept and Frequency of Safety Audit Programs: A Literatur Review

Abstract

The institutionalization of Safety Management Systems (SMS), following the adoption of
Annex 19 by the International Civil Aviation Organization (ICAO), has become a fundamental
component of contemporary aviation safety governance. Within this framework, safety audits
are positioned as a core element of safety assurance, intended to evaluate system effectiveness,
assess the adequacy of risk control measures, and support informed organizational decisionmaking. Despite the global standardization of SMS principles, considerable variation persists
in the design of safety audit programs, particularly in determining appropriate audit frequency.
This challenge is especially evident in Approved Training Organizations (ATOs), whose
operational environments integrate academic instruction, practical training, and safety-critical
activities. Although national aviation regulations, including those implemented in Indonesia,
act as regulatory drivers for SMS adoption, aligning audit frequency with operational risk
dynamics represents a global and systemic challenge shared by ATOs across jurisdictions.
This study examines the conceptual and empirical development of safety audit implementation
and audit frequency over the past fourteen years through a qualitative narrative literature
review conducted using a structured review protocol. The review process was informed by
PRISMA principles and employed predefined search strings related to safety audits, audit
frequency, Safety Management Systems, Safety Performance Indicators (SPIs), and aviation
training organizations across major academic databases. Inclusion criteria focused on peerreviewed publications published between 2011 and 2025 that addressed safety assurance
practices within aviation and other safety-critical domains. The synthesis of the literature
identifies a clear transition from periodic, compliance-oriented audits toward adaptive and
performance-based audit models increasingly informed by SPIs and prior safety performance
outcomes. Building on this synthesis, the study proposes a contextualized safety audit model
for ATOs that operationalizes the shift from periodic to performance-based auditing. The
model integrates system-based auditing, organizational safety culture evaluation, and SPIbased performance monitoring within the Plan–Do–Check–Act (PDCA) continuous
improvement cycle. In this framework, SPIs function as dynamic inputs for determining audit
frequency and scope: stable or improving SPI trends may justify extended audit intervals,
whereas deteriorating or volatile performance patterns trigger more frequent, targeted, and indepth audits. By replacing fixed, calendar-driven schedules with a risk-responsive approach,
the proposed model aligns audit intensity with actual operational exposure, supports
proportional allocation of audit resources, and strengthens early detection of emerging safety
risks. Through this adaptive structure, safety audits are positioned as active safety assurance
mechanisms that support continuous improvement, organizational resilience, and sustained
safety performance within the global aviation training environment