Enterprises manufacture their products under mounting global competition, prevalent on various strategic levels. It is, however, primarily experienced with respect to production costs and product quality. Facing the challenges of fierce competition, manufacturers attend to their customers' needs with high-degree customisability and personalisation, which proves to be increasingly difficult to meet under production optimisation constraints. Implementing certain components of flexible manufacturing systems may only partially solve the problem since it presents no case for raising the production costs while meeting deadlines and maintaining the highest quality of the product. Industry 4.0, a strategy that has been in the pipeline for several years, is considered to be the solution to the problems of the modern industry. In the future, flexible manufacturing systems are expected to be executed autonomously in a decentralised and horizontal structure of production management and control, as a step towards lean manufacturing and sustainability of operations fulfilling the requirements of manufacturing flexibility, productivity, production costs and customer satisfaction. This paper discusses the role of manufacturing flexibility in enterprises as the main domain of change. The efficient and proper operation of this area is a prerequisite for implementing the ideas of the Industry 4.0 concept in real conditions.