Manufacturing companies nowadays operate under volatile and uncertain market conditions that require them to pursue continuous improvements in productivity, cost efficiency, and operational flexibility. Lean Thinking offers companies a well-established set of principles for eliminating waste and improving process performance, however Lean initiatives frequently fail to sustain their early gains once implementation moves beyond its technical tools. This Master's thesis examines the similar aspects and synergies between Lean Thinking and Change Management theories and assesses how the two can be combined to support sustainable operational improvement in an industrial setting. The argument is tested through a case study based on an improvement project conducted during an internship, where the Overall Equipment Effectiveness (OEE) of a semi-automated fastener consumables assembly machine was investigated using the A3 problem-solving model.