There is a rapid change in the current market that requires more customisation and higher quality for a lower price. For SMEs, it is a challenge to compete and develop the production system in this increasingly competitive environment. One way to increase the competitive advantages is to investigate the possibilities to involve Lean tools such as VSM. The purpose of the VSM design is to get a quick holistic view of the production system to find value-added and non-value-added activities and improve the production system. A VSM is, however, not widely explored in a production system with high flexibility and a high number of variants in a functional layout. It has been discovered that there is a research gap in the literature, and some researchers proclaim that there is none or a negative correlation between VSM and flexible production. Therefore, there is a need to further explore these concepts together at a case company with these pa-rameters.The methodological approach is a single case study at a case company. The research focuses on investigating how the VSM can be applicable in a production system with high flexibility on a functional layout facility. The study will focus on hard aspects such as the VSM itself and soft aspects such as Lean concepts, Change Management, and employee’s behaviour and reactions. The reason is that enterprises need to investigate parameters and employee behaviour since a production system with high flexibility on a functional layout often perceives as a complex system. Therefore a conceptual model has been developed to facilitate the adoption of this kind of production system. The created conceptual model is based on the findings from the case company and theories from the literature studies. The methods that supported the data collection in the case are interviews with the production personnel and personnel from the management de-partment, observations, VSM and a literature review.