Purpose: Air Navigation Service Providers (ANSPs), within the European Union, are mandated, through multiple International and European aviation regulations, to implement and maintain a Management System. This study aims to successfully integrate all interrelated elements of separate Management Systems. Design/Approach/Methodology: A Lean Six Sigma (LSS) framework was utilised, adopting a DMAIC (Define, Measure, Analyse, Improve and Control) approach utilising various Lean Six Sigma tools within it to successfully integrate all interrelated elements of the separate Management Systems. Findings: The project demonstrated that the integration of Management Systems is fundamentally possible, but there are considerations and complications, specific to the type of industry, that should be considered as part of the integration. The project also found that a structured DMAIC approach, especially in organisations less experienced with LSS tools, provided a solid foundation and framework for the improvement project, and ensured adequate communications, deemed essential to the project’s success. Research Implications/Limitation: The project is specific to the aviation domain, and in particular ATM/ANS TrafficServices, a sector of the aviation industry), which is heavily regulated by multiple authorities and legislators, however, the principles could also be applied to other highlighted regulated and public sector organisations. Originality: This is not the first such project regarding integrating Management Systems; however, being a novel concept in ATM/ANS, it is the first such study, to the author’s knowledge, in the ATM/ANS landscape and in Ireland. LSS is a new concept in the aviation domain, and certainly in ATM/ANS, and the project demonstrates the benefits of an LSS application in an ATM/ANS public sector organisation.