Capacity coordination in hybrid make-to-stock/make-to-order production environments

One of the most important decisions in hybrid make-to-stock/make-to-order (MTS/MTO) production systems is capacity coordination. This paper addresses capacity coordination of hybrid MTS/MTO production systems which deal with MTS, MTO and MTS/MTO products. The proposed model is developed to cope with order acceptance/rejection policy, order due-date setting, lot-sizing of MTS products and determining required capacity during the planning horizon. Additionally, a backward lot-sizing algorithm is developed to tackle the lot-sizing problem. The proposed model presents a general framework to decide on capacity coordination without too many limiting mathematical assumptions. The model combines qualitative and quantitative modules to cope with the aforementioned problems. Finally, a real industrial case study is reported to provide validity and applicability of the proposed model. Having the model applied in the case study, considerable improvement was achieved.     

Combining make to order and make to stock

In inventory control and production planning one is tempted to use one of two strategies: produce all demand to stock or produce all demand to order. The disadvantages are well-known. In the make everything to order case (MTO) the response times may become quite long if the load is high, in the make everything to stock case (MTS) one gets an enormous inventory if the number of different products is large.In this paper we study two simple models which combine MTO and MTS, and investigate the effect of combining MTO and MTS on the production lead times.     

Production planning system for a combination of make-to-stock and make-to-order products

This paper deals with the problem of designing a production planning system for a combination of make-to-stock (MTS) and make-to-order (MTO) products where the production facility produces both types of products. Important management points in such production systems are to design an efficient production planning system which can shorten the manufacturing time of MTO products as well controlling the unfilled rate of MTS products to the market demand at a low level. A hierarchical production planning model is introduced in order to design the production planning system. The buffer capacity is set as a design variable for determining production capacity at a higher planning level, and the rule for allocating the production capacity to types of products is adopted as a design variable at a lower level. First, we analyse how these two design variables affect the unfilled rate of MTS products and the average manufacturing time of MTO products. Second, we clarify the relationship of the buffer capacity with the manufacturing time of MTO products and with the required buffer inventory level of MTS products which can maintain the unfilled rate of MTS products to the market demand within an acceptable limit. Third, we show an example of the range of design variables which can control the unfilled rate of MTS products and the manufacturing time of MTO products within their acceptable limits, if the individual limits of the performance measure is given to respond to customer orders quickly.     

Management of sustainable manufacturing systems-a review on mathematical problems

The ever-growing awareness of environmental protection has significantly influenced the method of manufacturing products. Due to the introduction of new processes, the management of sustainable manufacturing shows different characteristics to those of traditional systems. Sustainable manufacturing systems have attracted a great deal of attention in the past 20 years as an emerging manufacturing approach. Particularly in the last 10 years, the number of papers focusing on the topic of sustainable manufacturing systems’ management has increased rapidly. More and more practical factors have been considered and integrated into this area which makes it more complex, but closer to reality. This paper aims to classify the mathematical problems dealing with the management of sustainable manufacturing systems. More than 100 related papers mainly from 1994 to 2015 have been selected and reviewed and divided into three categories according to the main elements in a manufacturing system: production planning and control, inventory management and control and manufacturing network design. The development of each category is summarised and the corresponding mathematical problems are discussed to provide a general overview of the relevant research fields and identify future research directions.     

人道物流的协同机制

人道物流协同机制的研究有助于提高灾难救援的效率和效益,现已成为灾难管理和物流管理领域关注的焦点。在回顾相关研究文献的基础上,阐述了人道物流的概念和特点;分析了人道物流协同的影响因素和优势;介绍了目前人道物流协同机制的研究进展;并提出了进一步的研究方向。     

Make-to-order, make-to-stock, or delay product differentiation? A common framework for modeling and analysis

Delaying product differentiation is a hybrid strategy that strives to reconcile the dual needs of high variety and quick response time. A common product platform is built to stock in the first stage of production (called the Make-To-Stock (MTS) stage) which is then differentiated into different products after demand is known in the second stage (known as the Make-To-Order (MTO) stage). In this article, we develop models to compute the costs and benefits of delaying differentiation in series production systems when the order lead times are load dependent. The models are then used to gain insights through analytical and numerical comparisons. For example, we observe the following patterns in a large number of numerical experiments. The effect of congestion in the MTS and MTO stages is asymmetric with tighter capacity at the MTO stage having a greater detrimental effect on the desirability of delaying differentiation. If there is flexibility in choosing the point of differentiation, higher loading is observed to favor later differentiation. Also, if the sequence in which work is performed can be affected, then placing workstations that have a tighter capacity in the MTS stage lowers costs.     

Comparing TOC with MRP and JIT: a literature review

Since the early 1980s, manufacturing philosophies such as manufacturing resource planning (MRP), just-in-time (JIT), and theory of constraints (TOC) have emerged as distinct, viable, and competitive planning and control systems for improving the organisational performance. Comparative literature outlines many similarities and differences among these philosophies and attempts to answer the question: what is the best choice? With this question in mind, this paper reviewed the journal articles comparing TOC with MRP and JIT and provided specific future research directions. Although TOC is shown to compete effectively against MRP and JIT and thereby, holds promise, the results are still inconclusive primarily because the majority of journal articles lack in one respect or the other in terms of realistic examples modelled, breadth of characteristics considered, rigorous methodology employed, and depth of statistical analysis performed. In terms of future research directions, we develop a comprehensive list of characteristics by drawing on the literature reviewed and suggest some specific empirical as well as analytical research streams.     

Ageing workforce management in manufacturing systems: state of the art and future research agenda

The workforce ageing phenomenon is recently affecting most of the Organisation for Economic Co-operation and Development (OECD) member countries, due to a general ageing of their populations and a higher average retirement age of the workforce. In this paper, the topic of ageing workforce management is addressed from a production research standpoint, with the aim of understanding how older workers can be supported and involved in a manufacturing system. First, the current state of the art related to the ageing workforce in production systems is presented. This is structured according to four main topics: (1) analysis and evaluation of ageing workers’ functional capacities, (2) consideration of ageing workers’ capacities in industrial system modelling and management, (3) analysis and exploitation of ageing workers’ expertise, (4) acknowledgement, analysis, design and integration of supporting technologies. Next, the discussion on the impact of the ageing workforce on manufacturing systems’ performances leads to the comparison of some technological advances that are related to the Industry 4.0 paradigms. Finally, a future research agenda on this topic is proposed, based on the same topics classification proposed for the literature analysis. Five different research areas are derived, suggesting future directions for appropriate research concerning the employ of older workers in production environments.     

Characteristics of the research on reverse logistics (1995–2005)

This paper aims to describe and analyse the main characteristics of articles on reverse logistics published in the production and operations management field, in order to determine the evolution of this current research over recent years and improve our understanding of this issue. We built up a database with the articles on reverse logistics published in the most relevant journals within the period 1995–2005, and we have explored the topic, the methodology and the techniques of analysis, as well as other relevant aspects of the research. We have evaluated the first decade of research on reverse logistics, observing what has been done and how, where and by whom it has been carried out. The result is an extensive review of the research works that have created and developed the reverse logistics concept, outlining some directions of research for the near future and offering practical help to those who begin to research on this topic.     

Comparison of order-fulfilment performance in MTO and MTS systems with an inventory cost budget constraint

The make-to-order or make-to-stock decision is an important issue faced by firms in many industries. In the existing literature, optimisation models comparing the cost of making product to stock versus making it to order have been widely developed. Motivated by the problem faced by a machinery company, we examine the issue from a different perspective and formulate service-maximisation models with inventory cost budget constraints. We compare and analyse order-fulfilment performance measures for the two different production control systems. The goal is to identify the key influencing factors and devise a production strategy that maximises service performance subject to resource constraint. We show that the MTO production control system is preferred in the production system with low component values and long component processing times and high value and short lead time in the final assembly stage; while the MTS production control system is applicable to the production system with high component values and short component processing times and little value and long lead time in the final assembly stage.     

A capacity available-to-promise model for drum-buffer-rope systems

The capacity available-to-promise (CATP) concept, which is designed to enhance the available-to-promise (ATP) feature in MRPII for changing production strategy from make-to-stock (MTS) to make-to-order (MTO), was developed recently. In contrast to an ATP, which is the future uncommitted inventory as projected by master production schedule, a CATP provides a detailed and time-phased diagram of unused production capacity. Hence, a CATP can allow marketing personnel to establish realistic order promise dates and concentrate on selling idle capacity in the future, and enable customers to select their preferred future capacity. This study proposes a CATP model for drum-buffer-rope (DBR) systems. The DBR scheduling system is one of finite capacity schedule systems and is currently being implemented by a growing number of manufacturing companies. This CATP model can help DBR users improve the due-date promising and exploitation of bottleneck. This CATP model can also be embedded in current commercial or private DBR scheduling systems so as to enhance their effectiveness.     

Scheduling in production,supply chain and Industry 4.0 systems by optimal control: fundamentals,state-of-the-art and applications

This paper presents a survey on the applications of optimal control to scheduling in production, supply chain and Industry 4.0 systems with a focus on the deterministic maximum principle. The first objective is to derive major contributions, application areas, limitations, as well as research and application recommendations for the future research. The second objective is to explain control engineering models in terms of industrial engineering and production management. To achieve these objectives, optimal control models, qualitative methods of performance analysis and computational methods for optimal control are considered. We provide a brief historic overview and clarify major mathematical fundamentals whereby the control engineering terms are brought into correspondence with industrial engineering and management. The survey allows the grouping of models with only terminal constraints with application to master production scheduling, models with hybrid terminal–logical constraints with applications to short term job and flow shop scheduling, and hybrid structural–terminal–logical constraints with applications to customised assembly systems such as Industry 4.0. Computational algorithms in state, control and adjoint variable spaces are discussed.     

Theme evolution analysis of electrochemical energy storage research based on CitNetExplorer

With the rise in new energy industries, electrochemical energy storage, which plays an important supporting role, has attracted extensive attention from researchers all over the world. To trace the electrochemical energy storage development history, determine the research theme and evolution path, and predict the future development directions, this paper will use CitNetExplorer to draw citation chronology charts and study the development trends in this field by analysing data downloaded from the Web of Science database. The results indicate that the research in this field originated from the study on energy storage materials and gradually divided into two major fields: energy storage materials and applications after 2000. The research on the energy storage materials refers to activated carbon materials, carbon nanotubes, graphene, and mesoporous carbon materials. Energy storage applications mainly focus on power systems, new energy vehicles, and wind farm dispatch. For research on electrochemical energy storage materials, the industrialization of graphene may become a new trending topic, and the application research will turn to the construction of energy Internet systems in the future. This paper will provide a full map for the development of electrochemical energy storage and forecast the future research directions in this field.     

Throughput analysis of production systems: recent advances and future topics

Throughput analysis is important for the design, operation and management of production systems. A substantial amount of research has been devoted to developing analytical methods to estimate the throughput of production systems with unreliable machines and finite buffers. In this paper we summarise the recent studies in this area. In addition to the performance evaluation of serial lines, approximation methods for more complex systems, such as assembly/disassembly systems, parallel lines, split and merge, closed-loop systems, etc., are discussed. Moreover, we propose future research topics from the automotive manufacturing systems perspective.     

Planning projects with scarce resources: Yesterday,today and tomorrow’s research challenges

This paper is an invited request to describe the main research challenges in the domain of resource-constrained project scheduling. The paper is split up in three parts. In today’s challenges, research endeavors that have received a significant, but still not enough, attention have been described. In tomorrow’s research challenges, some promising research avenues for future research have been given. Finally, in yesterday’s challenge, a research topic that started decades ago, is said to have still a huge potential in tomorrow’s research agenda. This paper does not intend to give a full literature overview, nor a summary of all possible research paths. Instead, it is inspired from the author’s experience in academic research and practical consultancy and it serves as a personal opinion on a non-exhaustive set of promising research avenues, rather than giving a full literature-based advice for future research directions.     

Bone tissue engineering therapeutics: controlled drug delivery in three-dimensional scaffolds

This paper provides an extensive overview of published studies on the development and applications of three-dimensional bone tissue engineering (TE) scaffolds with potential capability for the controlled delivery of therapeutic drugs. Typical drugs considered include gentamicin and other antibiotics generally used to combat osteomyelitis, as well as anti-inflammatory drugs and bisphosphonates, but delivery of growth factors is not covered in this review. In each case reviewed, special attention has been given to the technology used for controlling the release of the loaded drugs. The possibility of designing multifunctional three-dimensional bone TE scaffolds for the emerging field of bone TE therapeutics is discussed. A detailed summary of drugs included in three-dimensional scaffolds and the several approaches developed to combine bioceramics with various polymeric biomaterials in composites for drug-delivery systems is included. The main results presented in the literature are discussed and the remaining challenges in the field are summarized with suggestions for future research directions.     

Tuning paradigm of external stimuli driven electronic,optical and magnetic properties in hybrid perovskites and metal organic complexes

We have witnessed a wide range of theoretical as well as experimental investigations to envisage external stimuli induced changes in electronic, optical and magnetic properties in the metal organic complexes, while hybrid perovskites have recently joined this exciting league of explorations. The flexible organic linkers in such complexes are ideal for triggering not only spin transitions but also a plethora of various different responses under the influence of various external stimuli like pressure, temperature and light. A diverse range of applications particularly in the field of optoelectronics, spintronics and energy scavenging have been manifested. The hysteresis associated with the light induced transitions and spin-crossover governed by pressure and temperature, are promising phenomena for the design principles behind memory devices and optical switches. The pressure induced optical properties tuning or piezochromism has also emerged as one of the prominent areas in the field of hybrid perovskite materials family. It is thus imperative to have a clear understanding of how the tuning in electronic, optical and magnetic properties occur under various stimuli, and selectivity of the stimulus could be influential behind the maximum efficiency in the field of energy and optoelectronic research, and in what future directions this field could be driven from the perspective of futuristic material properties. This review though primarily focuses on the theoretical aspects of understanding the different mechanisms of the phenomena, does provide a unique overview of the experimental literature too, accompanied by the theoretical understanding such that relevant device applications can be considered through a future roadmap of tuning paradigm of external stimuli. It also provides an insight as to how energy and memory storage may be combined by using the principles of spin transition in metal organic complexes.     

脑电研究在工业设计领域的现状与趋势分析

目的分析脑电(EEG)领域研究现状,为工业设计领域学者提供系统认知,并预测其未来发展趋势,为该领域的后续研究提供方向。方法采用大数据分析方法,选取CNKI数据库作为数据来源,对国内外相关论文数据进行分类和分析,从文献年度分布、研究层次分布、关键词分布3个角度进行分析,得出脑电在工业设计领域的研究现状,发现EEG在工业设计领域中的应用主要有感性工学、产品评价、交互设计和设计应用4个研究方向。结论对感性工学、产品评价、交互设计和设计应用4个主要方面进行深入分析,深入了解EEG在各个方面的研究发展现状和主要学者的文献,在此基础上提出了目前EEG研究存在的不足以及未来的研究趋势,为EEG在工业设计领域中的研究指出了方向。     

Modeling industrial lot sizing problems: a review

In this paper we give an overview of recent developments in the field of modeling deterministic single-level dynamic lot sizing problems. The focus of this paper is on the modeling of various industrial extensions and not on the solution approaches. The timeliness of such a review stems from the growing industry need to solve more realistic and comprehensive production planning problems. First, several different basic lot sizing problems are defined. Many extensions of these problems have been proposed and the research basically expands in two opposite directions. The first line of research focuses on modeling the operational aspects in more detail. The discussion is organized around five aspects: the set ups, the characteristics of the production process, the inventory, demand side and rolling horizon. The second direction is towards more tactical and strategic models in which the lot sizing problem is a core substructure, such as integrated production–distribution planning or supplier selection. Recent advances in both directions are discussed. Finally, we give some concluding remarks and point out interesting areas for future research.     

A review of operations management literature: a data-driven approach

Production and operations management has been a significant field of research for many years. However, other than an educated guess by researchers in the field or a perusal of textbook chapter titles, the major topics and their trends over time are not well established. This study provides a comprehensive review of production and operations management literature using a data-driven approach. We use Latent Semantic Analysis on 21,053 abstracts representing all publications in six leading operations management journals since their inception. 18 unique topic clusters were identified algorithmically. Just being aware of the history of research topics should be of great interest to all academics in the field, but to help future researchers we conducted three post hoc analyses: 1) analysis of methods used in all these studies, 2) citation rates by topic area over time, and 3) the growing prevalence of research covering multiple topics.