Lean has its origin in the Toyota Production System. Aiming to deliver customer value through people’s respect and waste reduction, Lean advocates five principles: value specification, value stream identification, flow, pull and perfection. Knowledge management, through the process of identifying, capturing and leveraging knowledge, became a source for competitive advantage for organisations. This paper aims a contribution to a better understanding of Lean combined with Knowledge Management (KM) tools, through the study of the outcome from Lean and KM tools adoption in invoice verification process at a Portuguese shared services organisation. The study analysed how the execution time of a process depends on the operators who perform it and if operators’ individual practices have an impact on the process execution time. The implementation process was surveyed through observations and statistical analysis, which identified differences in terms of practices used by operators. Statistical evidence made it clear that best practices adopted by operators have a positive impact in their execution times. Moreover, it was also important to notice that Lean and knowledge management combined practices can be useful to organisations in a transformation program, which will require standardisation, optimisation and process automation.