‘Unit load’ evolution: a chronological literature review from 1950-2020
Most industrial products move through the supply chain grouped together, or in other words are carried in ‘unit loads.’ Unit loads facilitate and increase the efficiency of material handling, storage, and the distribution process. Moreover, unit loads reduce handling costs and the probability of damage by reducing individual unit handling. With the novelty of Industry 4.0, logistics and material handling systems were forced to improve in order to cope with growth in new technologies. This paper presents a state-of-the-art review of publications on unit load problems, as well as builds an analysis and draws a conclusion for the unit load research timeline through the past several decades (from 1950 to 2020). Approximately 130 different articles and resources were collected and investigated thoroughly in order to compare their objectives, contributions, methodologies, conclusions, and gaps. This paper summarizes the result of this chronological literature review, suggesting different classifications and findings.