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This article defines a new dynamic storage assignment problem (DSAP) and develops an integrated mechanism for optimization purpose, based on the ABC classification and mutual affinity of products. A product affinity-based heuristic (PABH)-a technique based on data mining-is developed for calculation of pairwise relationships between products. It is shown that the analytical and multi-parametric DSAP is a quadratic assignment problem (QAP) and thus non-deterministic polynomial-time (NP)-hard. A greedy genetic algorithm (GA) is therefore developed for handling the computational complexity of the DSAP. Performance comparisons between the new approach and the traditional ABC classification method are conducted. The experimental results show that a preferred storage assignment approach is to simultaneously maximize the sum of affinity values and the product of zone indicators and order frequencies based on traditional ABC classification. The experiments on a distribution center of a family care product manufacturer indicate 7.14 to 104.48 % improvement in the average order picking time. [ABSTRACT FROM AUTHOR]

Dynamic scheduling of the storage/retrieval (S/R) requests and increasing the utilization of the storage spaces, are the two common approaches to improve the efficiency of the automated storage/retrieval systems (AS/RS) in industry practice. However, the actual improvement of the AS/RS has to be justified from the perspective of computer integrated manufacturing system (CIMS) because the ultimate objective of the AS/RS is to assist the CIMS in enhancing its material handling efficiency as well as synchronizing the production. Targeting on this crucial requirement, a dynamic availability-oriented controller (DAOC) is developed in this paper to minimize the mean request fulfilment time of the AS/RS. Firstly, while considering the three types of critical dynamic constraints from the CIMS’ shop floor: the availabilities for both machines and the AS/RS, the process plan of the product, and the production schedule, DAOC is capable of determining the optimal execution sequence of the S/R requests issued from the CIMS and activating dynamic storage space consolidation commands of the AS/RS. Secondly, simulation experiments are conducted and the results show that DAOC successfully improves the S/R request control scheme of the traditional class-based assignment method and significantly outperforms four comparable approaches under various CIMS configurations. [ABSTRACT FROM AUTHOR]