A reactive multi-flow approach to the planning and control of flexible machining facilities

The need for generating efficient planning and control systems for flexible machining facilities has further increased with the pressures of the modern global market, in which there is an urgency for greater reactivity to highly individualistic customer desires and an unpredictable pattern of production demands. This paper describes the design and realization of an integrated planning and control system in which a two-phase planning approach is adopted to generate schedules for medium-term and short-term planning horizons, in order to improve the reactivity of the system to the dynamic changes in demand and production capacities. Furthermore, this novel system referred to as a 'multi-flow controller', enables short-term planning for the flows of workpieces, fixtures and cutting tools within flexible machining facilities to be carried out simultaneously, thus increasing the cohesion among machining activities through the introduction of bespoke schedules for tooling and fixturing operations. The multi-flow controller utilizes a graphical interface to act as an 'advisory system' to the person responsible for the generation of production schedules, and supports the frequent interactions required to modify the generated schedules due to manufacturing disturbances. The paper illustrates the application of such a planning and control system within a typical flexible machining cell configuration.