Background - Lean paradigm has been successfully employed in the manufacturing sector in past decades, however in the engineering services sector its application has unfortunately not received the same attention both from academia and industry.   Problem Discussion – The negligence of Lean in the engineering services sector rendered this sector deprived from Lean’s proven benefits in the manufacturing sector. The reason for this negligence can be traced back to the fact that Lean’s implementation is not a straightforward task and additionally its direct translation from the manufacturing sector into the engineering services sector may impede innovative capabilities of the engineering services sector that are crucial for its sustainable growth.   Problem Formulation - In addressing the aforementioned issues, this thesis investigates the following key research question: “Whether and how Lean Innovation can be implemented in the engineering services sector?”   Purpose - This work explores and employs different modern theoretical concepts from literature to promote Lean Innovation in the engineering services sector by first developing a theoretical framework in terms of nine propositions and then examining them through a qualitative empirical research.   Methodology - The qualitative empirical research is conducted by first gathering empirical data through expert interviews and then analysing it employing the directed content analysis technique in order to examine the nine propositions promoting Lean Innovation.    Findings - This study concludes that Lean Innovation in the engineering services sector is achievable by employing modern theoretical concepts like open innovation, the systems approach to problem solving and transformational leadership in a thoughtful and planned manner.   Limitations - The lack of depth of the theoretical as well as empirical research focus in terms of the sample size and quality stemming from the challenge of finding enough experts with versatile knowledge in the thesis’ timeframe can be considered as limitations on the quality of this research.