Industrial Assessment of No Fault Found (NFF) Phenomena, Identification of Lean Wastes and Solution Through Soft Lean Practices in Aviation MRO

In the context of the aviation industry, No Fault Found (NFF) is a phenomenon that develops from a pilot experiencing a fault, but post-flight inspections are unable to replicate the reported fault. The occurrence of NFF remains a significant operational challenge, contributing to unnecessary maintenance actions, increased operational costs, and resource wastage. Previously six paradigms (Fault Diagnosis, System Design, Reliability Engineering, Data Management, Human Factors & Economic Analysis) of NFF have been explored, however the implication of NFF (lost labor hours, maintenance expenses, packaging/handling costs, equipment down time and transportation expenses) etc. have not been interlinked with lean wastes (defects, overproduction, waiting, underutilized talent, transportation, excess inventory, unnecessary motion, and over-processing). This study proposes a new seventh paradigm of “Lean Framework” by undertaking a comprehensive industrial assessment of the NFF phenomenon at the Aviation Maintenance, Repair, and Overhaul (MRO) sector through a structured research process. Based on responses from 50 aviation maintenance professionals, the study identifies the key eight lean wastes attributable to NFF events. High mean scores across all waste categories highlight resource wastage resulting from NFF events. In response to these findings, human-centered six soft lean practices have been proposed as effective solutions: leadership commitment, supplier collaboration, team-based problem solving, continuous process improvement, technical personnel training, and stakeholder feedback system. The proposed novel lean framework offers a practical, scalable approach for Aviation MRO organizations aiming to reduce NFF waste, optimize operational performance, and promote a culture of continuous operational excellence.