A method for online reconfiguration of a node in a process control system including components. Each component is a separate executable running in a separate operating system process as provided by a real time operating system of the node. A method is performed by a node manager of the node to be reconfigured. The method includes triggering, based on new configuration data and whilst running the at least one of the components to be reconfigured, creation of a new configuration entity for each of the at least one of the components to be reconfigured, the creating involving implementing, by each new configuration entity, a part of the reconfiguration corresponding to its component to be reconfigured. The method includes triggering synchronization of runtime data in each new configuration entity with runtime data of its corresponding existing configuration entity. The method includes triggering replacement of the existing configuration entity with its new configuration entity and thereby reconfiguring the node.