Incorporating human factors in order picking planning models: framework and research opportunities

Order picking (OP) activities, essential to logistics operations, are laborious and time-intensive. Humans are central actors in the OP process and determine both OP effectiveness and efficiency. Many researchers have developed models for planning OP activities and increasing the efficiencies of such systems by suggesting different warehouse layouts, OP routes or storage assignments. These studies have, however, ignored workers’ characteristics, or human factors, suggesting that they cannot be substantiated, which led to only partially realistic results. This paper proposes a conceptual framework for integrating human factors into planning models of OP activities and hypothesises that doing so improves the performance of an OP system and workers’ welfare. The framework is based on a systematic literature review that synthesises findings documented in the OP and human factors literature. The results of the paper may assist researchers and practitioners in designing OP systems by developing planning models that help in enhancing performance and reducing long-term costs caused by work-related inefficiencies.     

Training needs analysis—a human factors analysis tool

Human factors (HF) engineers have contributed to the reduction of human error, by improving user performance through the design of the user interface. However, there still remains a requirement for user training. This is especially true for complex, high risk processes employing new technology. Reduced manning and downskilling are putting increased pressures on users who, in many activities, still remain the last level of safety protection. In responding to this need, HF engineers now employ a range of tools and methods during the design process, which assist in identifying the training media and training design. Training needs analysis (TNA) offers a structured methodology to facilitate the information gathering process and identify any shortfall between current user performance and that demanded by new technology and designs. By the use of these methods and tools the potential for human error can be reduced, for the following reasons: (a) improved user performance (b) better designed and more efficient training systems. Existing TNA methods have been better suited to the study of existing equipment. This paper describes the training requirements process, and proposes a usable methodology for contractors conducting a TNA in the design of new systems/equipment. It is of particular use where information on the operation or maintenance may be limited.     

Towards a human factors and ergonomics integration framework in the early product design phase: Function-Task-Behaviour

Considering the existing methodologies’ hysteresis and cost of the human factors and ergonomics (HF/E) integration in the design phase, this paper attempts to develop a time-saving, less expensive and standard approach for designers to integrate the HF/E from the early design phase. In this study, the HF/E information is embodied by a user manual, which will be continuously improved with the refinement of design. A Function-Task-Behaviour framework is proposed to restate the design process, which involves three steps: (1) Functional specification involves function definition and decomposition according to initial user manual and other requirements; (2) Embodiment refers to conducting task definition and planning to achieve the intended function. SysML is used for task definition and PERT method is applied for task planning; (3) Detailed design refers to the interactions analysis between user’s behaviour and product’s behaviour in the work area. A case study is shown at the end of this paper to illustrate the feasibility of the proposed method in integrating the HF/E from the early design phase to improve the final performance of both product and user.     

Synergistic inhibition between OP and NaCl on the corrosion of cold-rolled steel in phosphoric acid

The effects of single OP and the mixture of various concentrations of OP and 0.1 M NaCl on the corrosion of cold-rolled steel in 1.0–3.5 M phosphoric acid have been investigated by using weight loss method and polarization method. This study revealed that cold-rolled steel in phosphoric acid has been more efficiently inhibited by OP in the presence of NaCl than single OP, and inhibition efficiency increases with increasing concentration of OP at the same temperature, but decreases with increasing temperature studied. A synergistic effect exists when OP and chloride ion are used together to prevent cold-rolled steel corrosion in 1.0–3.5 M phosphoric acid at every experimental temperature. The polarization curves showed that OP is a cathodic inhibitor, while the complex of OP and NaCl is a mixed-type inhibitor that mainly inhibits the cathodic corrosion of the steel. The experimental results suggested that the presence of chloride ion in the solution stabilized the adsorption of OP molecules on the metal surface and improved the inhibition efficiency of OP. The adsorption of single OP follows the Langmuir adsorption isotherm, and the adsorption of the complex accords with the Langmuir adsorption isotherm too. Some thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy have been calculated by employing thermodynamic equations. Kinetic parameters such as apparent activation energy and pre-exponential factor have been calculated and discussed. In 1.5–3.5 M phosphoric acid, the concentration pre-exponential factor and acid concentration constant have been calculated, and the synergistic effect has been observed too.     

Automated order picking systems and the links between design and performance: a systematic literature review

With new market developments and e-commerce, there is an increased use of and interest in automation for order picking. This paper presents a systematic review and content analysis of the literature. It has the purpose of understanding the relevant performance aspects for automated, or partly automated, OPSs and identifying the studied links between design and performance, i.e. identifying which combinations of design aspects and performance aspects have been studied in previous research. For this purpose, 74 papers were selected and reviewed. From the review, it is clear that there has been an increased number of papers dealing with the performance of automated, or partly automated, OPSs in recent years. Moreover, there are differences between the different OPS types, but, overall, the performance categories of throughput, lead time, and operational efficiency have received the most attention in the literature. The paper identifies links between design and performance that have been studied, as well as links that appear to be under-researched. For academics, this paper synthesises the current knowledge on the performance of automation in OPSs and identifies opportunities for future research. For practitioners, the paper provides knowledge that can support the decision-making process of automation in OPSs.     

Additive manufacturing management: a review and future research agenda

Based on the phenomenal changes that additive manufacturing (AM) has brought to industries and markets, managerial approaches should be re-examined and developed to take advantage of emerging opportunities. This revolutionary technology is dramatically changing business and innovation models, shrinking supply chains and altering the global economy. For example, 3D printing shifts production locations closer to customers and leads to free-form product design as well as sustainable manufacturing. Several studies have been conducted on AM technology, but the research stream on AM management is still developing, with studies dispersed in journals across different research areas. Our study presents both systematic and quantitative analyses of the literature, including co-citation analysis, factor analysis and multidimensional scaling, to explore the structure of the AM research domains in the scope of management, business and economics. We found eight main research streams: AM technology selection, supply chain, product design and production cost models, environmental aspects, strategic challenges, manufacturing systems, open-source innovation and business models and economics. Finally, based on the results of our in-depth analysis of the literature, we found nine promising future research directions.     

One-piece flow manufacturing on U-shaped production lines: a tutorial

Now-a-days shorter product life cycles and increased demands for customization make it difficult to produce some products on traditional production lines. Often the best that can be done is to produce them in batch flow systems that have been improved through the incorporation of line flow principles. This is one-piece flow manufacturing. Traditional cells with irregular material flows are replaced by U-shaped production lines within which flow is regular and paced by a cycle time and between which flow is controlled by pull signals. This tutorial examines the research literature on one-piece flow manufacturing. It begins with the decisions rules that determine when one-piece flow is appropriate. Next the unique elements of one-piece flow (takt time, standard work, flow manufacturing on U-shaped lines, pull production, and jidoka) are reviewed. Then the mathematical models that are used to design one-piece flow systems are examined. Finally areas where more research is needed are discussed.     

A model for rest allowance estimation to improve tasks assignment to operators

Manual activities are still present in production systems, such as order picking in warehouses, material handling in production systems, loading and unloading of work centres. Many scientific contributions have widely demonstrated production system efficiency is strictly linked to the operator wellbeing. In fact, activities at different pace and duration imply different productivity but also different effects on the fatigue accumulation acquired by the operators, with consequently required resting period. It is necessary to integrate operator fatigue and recovery analysis into traditional decision support models for the design and management of production systems.

This paper aims to present an analytical model for setting the time necessary for operators to recover from the performed activity. According to previous research, the exponential trend of fatigue accumulation and recovery alleviation is studied. The energy expenditure rate, predicted with heart rate monitoring, is used to model the fatigue/recovery level, varying the physiological factors of the operators and the characteristics of the analysed manual activities. The model is limited to the activities where the whole body is used rather than a specific part stressed continuously. Finally, it is applied to optimise the scheduling of activities among operators in a manual order picking system. It is demonstrated that its use improves performance in terms of productivity.     

Strategic success factors in enterprise resource-planning design and implementation: a case-study approach

Enterprise Resource Planning (ERP) has gained popularity among many organizations that seek to increase the efficiency and productivity as well as to streamline their operations. ERP systems are a well-known concept. The available holistic literature and theory in ERP are, however, scarce. This paper surveys current ERP literature and identifies the present state of theory in ERP by formulating propositions for four ERP strategic factors (Cost of ERP Implementation, Implementation Time and Return On Investment (ROI) Issues, ERP Employee Training, and Effective Use of ERP Features/Applications). The approach used in this research is grounded theory development. The propositions for ERP strategic factors are in turn delineated and evaluated in terms of specific subfactors associated with each factor. This is accomplished by the use of interview protocol and within the context of an in-depth analysis of two companies in different industries that have used ERP systems. The analysis of these case studies results in 15 revised propositions for ERP strategic factors and insights regarding the ERP practices. Based on these strategic factors, strategic subfactors, ERP revised propositions, and insights gained, a set of conclusions, managerial implications, and future research directions is presented.     

The measurement of Italian universities’ research productivity by a non parametric-bibliometric methodology

This paper presents a methodology for measuring the technical efficiency of research activities. It is based on the application of data envelopment analysis to bibliometric data on the Italian university system. For that purpose, different input values (research personnel by level and extra funding) and output values (quantity, quality and level of contribution to actual scientific publications) are considered. Our study aims at overcoming some of the limitations connected to the methodologies that have so far been proposed in the literature, in particular by surveying the scientific production of universities by authors’ name.     

Optimal design of multi-response experiments using semi-definite programming

Optimal design of multi-response experiments for estimating the parameters of multi-response linear models is a challenging problem. The main drawback of the existing algorithms is that they require the solution of many optimization problems in the process of generating an optimal design that involve cumbersome manual operations. Furthermore, all the existing methods generate approximate design and no method for multi-response n-exact design has been cited in the literature. This paper presents a unified formulation for multi-response optimal design problem using Semi-Definite Programming (SDP) that can generate D-, A- and E-optimal designs. The proposed method alleviates the difficulties associated with the existing methods. It solves a one-shot optimization model whose solution selects the optimal design points among all possible points in the design space. We generate both approximate and n-exact designs for multi-response models by solving SDP models with integer variables. Another advantage of the proposed method lies in the amount of computation time taken to generate an optimal design for multi-response models. Several test problems have been solved using an existing interior-point based SDP solver. Numerical results show the potentials and efficiency of the proposed formulation as compared with those of other existing methods. The robustness of the generated designs with respect to the variance-covariance matrix is also investigated.     

The growing complexity in invention process

Technological and design process complexities may pose challenges to engineering design and related outcomes through invention. Understanding the trends related to the complexity of inventions and invention processes is crucial for informing engineering design research and education for invention, but has not been formally developed in the design literature. Herein, we utilize a set of patent-based metrics, drawn from complex systems research and engineering design research, to detect various aspects of the complexity in invention processes. By an analysis of U.S. patents from 1975 to 2011, our results suggest that technology inventions have been increasingly (1) requiring larger teams and more distant collaboration, (2) integrating a growing base of prior technologies, and (3) delivering more systemic and integrative new technologies. These trends may positively reinforce each other so as to contribute to a continual growth of the complexity in invention processes. Individual productivity for invention is also in decline, as we measured from the patent data. These findings suggest the increasing importance of research, education and application of complex system analysis methods and tools to control and manage the complexity in invention processes.     

ELASTICITY ANALYSIS FOR CYCLONE OPTIMISATION

High performance cyclone can be designed using optimisation techniques. Elasticity analysis has been used to demonstrate its utility for optimum design of cyclone. In this paper effectiveness factor, q(q = -In P_n/(▵P.Surf)) is used for elasticity analysis. Various standard equations have been studied and compared on the basis of this effectiveness factor. Optimum gas outlet diameter and effect of particle size on it, is presented for various design models available in literature. It is concluded that it is possible to increase the efficiency of an existing cyclone by charging the gas outlet diameter to an optimum value calculated from elasticity analysis. This will avoid any major modification in the existing cyclone to increase the collection efficiency of the cyclone.     

A comprehensive literature review and analysis of the design,balancing and scheduling of assembly systems

This paper reports the results of a comprehensive review and analysis of the assembly line balancing literature. Quantitative developments and qualitative issues are addressed at both the strategic and tactical levels. The numerous quantitative and qualitative factors which the literature mentions could impact the design, balancing and scheduling of assembly systems are organized into an eight-level hierarchical, factor/decision taxomony. This comprehensive taxonomy is used to assess our progress in assembly system design and operation. Finally, from the results of the literature review and progress assessment, suggestions for future research on socio-technical assembly systems are offered.     

Machine interference—a comparison of two patrolling methods

Tables of efficiency for a set of machines regularly patrolled by one operator have been produced. The theoretical basis of the tables has been described elsewhere. The numerical results show that unidirectional patrolling produces a small but consistent advantage over bi-directional patrolling, both in the case of manual repairs and automatic repairs which may not always be successful. This has implications for the design and layout of the machines on the factory floor. In addition, the tables can be used to determine the optimum number of machines to allocate to an operator.     

The synergistic inhibition of the cold rolled steel Corrosion in 0.5 M sulfuric acid by the mixture of OP and bromide ion

The synergistic inhibitive effect of the mixture of OP and NaBr on the corrosion of cold rolled steel in 0.5 M sulfuric acid has been investigated using weight loss and polarization method. The results reveal that corrosion of cold rolled steel has been efficiently inhibited by OP in the presence of NaBr in sulfuric acid, and inhibition efficiency increases with increasing concentration of OP at a constant temperature. A synergistic effect has been observed for OP with NaBr at all investigated temperatures (except 30 °C). The polarization curves show that the mixture of OP and NaBr is a cathodic inhibitor. The experimental results suggest that the presence of bromide ion in the solution stabilizes the adsorption of OP molecules on the metal surface and improves the inhibition efficiency of OP. Langmuir adsorption isotherm equation is obeyed at all the temperatures studied. The results obtained from weight loss and polarization method are in good agreement. The present study is important for the practical use of surfactant as corrosion inhibitor for steel in acidic media.     

Prototype models for two-dimensional layout design of robot systems

This paper provides a structure for analysis and design of layouts for robotic systems. Unique features are identified and classified; prototype models are formulated to clarify specific design issues. These models formalize the existing qualitative literature dealing with robot systems, augment other quantitative approaches by demonstrating application of mathematical programming, and suggest topics of research to develop efficient solution algorithms.     

Managing evolutionary paths in Sales and Operations Planning: key dimensions and sequences of implementation

Sales and Operations Planning (S&OP) is a key process that improves integration and communication between business functions and aligns the plans of a company into one integrated set of plans. This article focuses on the so-called S&OP ‘maturity models’, which describe the successive stages in the advancement of S&OP process according to a precise set of dimensions. These models are specifically thought to plan the transitions towards advanced stages, rather than to provide guidance on how to execute them. This paper aims to address this research gap by investigating how the dimensions evolve and interact during the execution of the transition between two subsequent stages. Three case studies of S&OP transitions with different starting and destination maturity stages have been compared. The findings demonstrate that the degree of seriality vs. parallelism among actions on different S&OP dimensions during the transition depends on the evolution stage of S&OP process. The study sheds light on the dynamics among the dimensions during the different transitions and warns managers not to underestimate the criticality of the people and organisation dimension, whose importance grows as the maturity level increases.     

一种基于流形学习和 KNN算法的柴油机工况识别方法

不同负荷状态下的柴油机振动、温度、转速等信号显著不同,而机组故障信号特征往往淹没在随负荷变化而剧烈变化的信号中,因此变负荷状态下的柴油机故障监测诊断难度较大,一直困扰着柴油机的实际故障诊断工作。本文提出了一种基于流形学习和KNN算法的柴油机工况识别方法,为柴油机变负荷工况下故障监测预警打下基础。方法融合机组的多源信号特征构建特征向量,通过流形学习t-分布邻域嵌入算法（t-SNE）实现特征向量的维数约简和敏感特征提取,采用K最近邻分类算法（KNN）完成柴油机运行负荷状态的自动分类。正常及故障状态下的柴油机信号验证了方法的有效性和实用性。