1,726,753 research outputs found
Erratum to: “A sustainable EOQ model: Theoretical formulation and applications” [Int. J. Prod. Econ. 149 2014 145–153] (International Journal of Production Economics (2014) 149 (145–153), (S092552731300296X), (10.1016/j.ijpe.2013.06.026))
No full textIn this erratum, we correct a typo in the formulations, due to the omission of one parameter, that appears in our paper “A sustainable EOQ model: Theoretical formulation and applications” (Battini, D., Persona, A., Sgarbossa, F., 2014). Erratum In the paper (Battini, D., Persona, A., Sgarbossa, F., 2014), equation (6) presents one typo, since the parameter b (space occupied by a product unit [m3/unit]) is omitted. The correct equation (6) and related equations (10)–(12) are as follows: [Formula presented] [Formula presented] [Formula presented] [Formula presented] This typo about the parameter b is also in equation, based on the same approach of equations (6) and (10). The correct equation (18) and related equations (19)–(21) will be: [Formula presented] [Formula presented] [Formula presented]. Finally, we would like to take this opportunity also to inform the reader that there are other small typos, due to the copy and paste of values formatting table 4 of Battini et al. (2014). These typos are not related to the previous omission of the parameter b. The correct value of the C(EOQ) in Case 2 is 417,336.47 instead of 419,719.47, the correct value of C(S-EOQ) is 418,990.90 instead of 421,367.07 and the internal transportation cost is 7530.59 instead of 9910.59. As a consequence, also Fig. 5 at Battini et al. (2014), representing these values, will be slightly different. Acknowledgements We would like to thank Leopoldo Eduardo Cárdenas-Barrón and Alfonso Angel Medina-Santana from Tecnológico de Monterrey, Mexico. Their valuable attention in reading and checking the paper helped us in correcting this typo. Reference Battini, D., Persona, A., & Sgarbossa, F. (2014). A sustainable EOQ model: Theoretical formulation and applications. International Journal of Production Economics, 149, 145-153
An Integrated Reference Model for Production Planning and Control in SMEs
No full textVersatile manufacturing (VM) companies typically manufacture
high variety, mainly customised products in relatively low
volumes, competing for each order with other supplier
companies on the basis of price, technical expertise, delivery
time and punctuality. The research presented in this study is
included in a wide cross-disciplinary project which involved
seven research centres. In particular, this paper aims at
identifying the general requirements and guidelines for the
definition of an integrated model of the order to delivery cycle in
a VM environment, which can particularly be suitable for the
small-medium enterprise needs. A number of guidelines
emerged, mainly in the areas of customer requirements
definition and commercial configuration of customer order,
supply and production planning, and intermediate and final
project evaluation
Warehouse picking or putting? A preliminary study to understand their applicability to fresh products
Full text linkAmong all warehouse operations, the preparation of customers' orders often represents a challenge. From one side, there is the need of fulfilling the requirements of the customers in short time windows; from the other side, there is the need of limiting operative costs. Moreover, when considering fresh products other aspects come into play, such as product quality and freshness, related to the time perspective, and the refrigerated storage, more linked to the cost dimension. In this paper, we propose the comparison of two alternatives for orders preparation, warehouse picking and warehouse putting, to understand when a configuration can be more appropriate than the other. First, we describe the two systems by highlighting strengths, weaknesses and differences. Then, we propose some mathematical formulations to measure time performance, occupied space and costs, also including energy consumption related to the storage of fresh products. The formulas are applied to real data, showing that the applicability of one system with respect to the other clearly depend on the number of orders per day and the number of stock keeping units
Shared human-AGV industrial environments: overview of the literature evolution and future researches
No full textAutomated Guided Vehicles (AGVs) continue to play a significant role in many manufacturing systems. More recently, the traditional AGV-human scenario, where workers and vehicles were managed in a separate way, has changed according to the Industry 4.0 revolution, in which robots and people coexist by sharing common tasks and closed movements in the same workplace without barriers. In this context, the safety of the human worker is one of the main concerns and a prerequisite for a successful collaboration between human and robots. Although the binomial man-robot has been frequently addressed over the last years, it is also true that most of the research on AGVs fleet design is focused on the sizing of the system by a performance point of view, without a complete acknowledgement of the interactions and of the mutual interferences among operators and AGVs. Indeed, the introduction of human-AGV shared environments (such as a mobile fulfilment system designed to follow the picker among the shelves and to collaborate with him) poses new challenges in the design and implementation of AGV systems. Thousands of articles about AGVs are present in the main publications’ databases in the time range from the 90s to the present day. The literature is very extensive and over the years has ranged between different areas of interest, riding the trail of new technologies and development trends. This work aims to show an overview of the evolution of the literature focused on AGV systems, emphasizing the latest research trends and the emerging gaps, also including the ones related to the shared presence of humans and AGVs within the same environment, which can affect the overall performances and the implementation phases
Availability in Human order picking systems: an empirical study on worker’s performance profile
No full textThe precise estimation of the performance of an order picking system can hugely resent from its availability; availability resents from the presence of behavioral aspects that are difficult to predict, such as the variability of human efficiency due to the influence of individual productivity profiles. These subjective factors are closely related to worker behavior, and, for this reason, they are difficult to express with mathematical functions that can generalize their overall effect on performance deviance in manufacturing systems. Based on a manual order picking system case study, this research proposes an empirical analysis of the work performance during a single work shift. This work considers the discretionary management of picker microbreaks as a source of deviation from work schedules for clustering different performance profiles based on picker productivity data. A deductive approach based on availability analysis was carried out to outline individual productivity profiles capable of incorporating all performance-relevant input factors to determine the attitude of different groups of workers to behave and work similarly
Human beings influencing assembly line performance: A comparison of job rotation strategies
Full text linkIndustries recently have faced high uncertain market demand with a greater product variety and a shorter life cycle. The primary aim of assembly systems is to increase line efficiency by maximizing the ratio of throughput to incurred costs while maintaining high flexibility. Workers are essential in determining line performance since most assembly tasks are still manual. Consequently, worker diversity plays a critical role in the operation of an assembly line, not only in terms of efficiency and productivity, but also from a human perspective. The human factor has a significant impact on task execution times and the overall production process; in any event, few studies considered human beings in assembly line operations. This study aims to explore the effect of human beings on assembly line performance; the case of an Italian company in which workers' behavior deeply influences production performance is presented, with the aim of analyzing different alternatives for the planning strategy in order to meet this requirement. The studied assembly line consists of three manual workstations and two automated workstations. It operates in a multi-model production environment and has an imbalance level of 50%. The proposal is to manage the allocation of workers through job rotation scheduling to ensure equal treatment despite different levels of efficiency. The study outlines three scheduling alternatives, highlighting the advantages and disadvantages of each
An Integrated reference model for production planning and control in SMEs
No full textVersatile manufacturing (VM) companies typically manufacture high variety, mainly customised products in relatively low volumes, competing for each order with other supplier companies on the basis of price, technical expertise, delivery time and punctuality. The research presented in this study is included in a wide cross‐disciplinary project which involved seven research centres. In particular, this paper aims at identifying the general requirements and guidelines for the definition of an integrated model of the order to delivery cycle in a VM environment, which can particularly be suitable for the small‐medium enterprise needs. A number of guidelines emerged, mainly in the areas of customer requirements definition and commercial configuration of customer order, supply and production planning, and intermediate and final project evaluation
Throughput models for a dual-bay VLM order picking system under different configurations
No full textValutazione degli indici di costo e prestazionali per impianti antincendio su linee di verniciatura
No full text- …
