A high-speed reallocation algorithm for controlling man-machine production systems

An on-line control model for a two-level man machine production system is considered. The system comprises a section with several production units and manufactures different products with planned target amounts by utilizing several types of non-consumable resources. Each unit may operate at several possible speeds which are subject to random disturbances. The unit's output can be measured only at pre-given control points. At the unit level, control actions result in determining control points and production speeds. At the section level, production control centres on reallocating resources and target amounts among the units. The performance of the two-level control algorithm depends mainly on solving the reallocation problem, as the latter takes more computational time than other control actions. Thus, speeding up the reallocation algorithm results in enhancing the control model's performance. We suggest a newly developed reallocation model, together with a corresponding reallocation algorithm. Two objectives are embedded in the model: (i) to maximize the delivery performance of the slowest unit so that it can meet its target on time, on condition that only maximal speeds are used; and (ii) to maximize the delivery performance of the latest product so that it is manufactured on time under the same conditions. A subsidiary iterative switching algorithm is developed by following both objectives. A generalized reallocation algorithm, which is a combination of the iterative algorithm and the coordinate descent method, is suggested. Such a reallocation algorithm significantly enhances the control model's performance and enables large-size man-machine production systems to be controlled under random disturbances. Extensive experimentation has been carried out to verify the efficiency of the reallocation algorithm. The algorithm has been used successfully in a real industrial plant.