The purpose of the research outlined in this paper is to explore the question of how the Lean concept evolves at a strategic management level in an international manufacturing company. The firm has set out to review its strategy and management system in a series of workshops to meet upcoming challenges in a business environment under transformation. Full access to the ongoing strategic work and related documents facilitates the execution of this longitudinal case study that started in March 2019. The empirical findings demonstrate concrete examples from the process of developing a management system that has its foundation in Lean production. One model comprising three types of co-existing conceptual management systems is presented, illustrating a scenario of how to handle the expected increasing industrial complexity. An opportunity to learn and further develop from the three types of management systems arise. The data further displays examples of the presence of co-existing corporate versions of the management system as a possible reaction to the different contexts and challenges at hand. The research suggests and further elaborates on the phenomenon of co-existing management systems and management systems development based on Lean.