In this paper, we briefly review the development of ranking and selection (R&S) in the past 70 years, especially the theoretical achievements and practical applications in the past 20 years. Different from the frequentist and Bayesian classifications adopted by Kim and Nelson (2006b) and Chick (2006) in their review articles, we categorize existing R&S procedures into fixed-precision and fixed-budget procedures, as in Hunter and Nelson (2017). We show that these two categories of procedures essentially differ in the underlying methodological formulations, i.e., they are built on hypothesis testing and dynamic programming, respectively. In light of this variation, we review in detail some well-known procedures in the literature and show how they fit into these two formulations. In addition, we discuss the use of R&S procedures in solving various practical problems and propose what we think are the important research questions in the field.
The global collaboration and integration of online and offline channels have brought new challenges to the logistics industry. Thus, smart logistics has become a promising solution for handling the increasing complexity and volume of logistics operations. Technologies, such as the Internet of Things, information communication technology, and artificial intelligence, enable more efficient functions into logistics operations. However, they also change the narrative of logistics management. Scholars in the areas of engineering, logistics, transportation, and management are attracted by this revolution. Operations management research on smart logistics mainly concerns the application of underlying technologies, business logic, operation framework, related management system, and optimization problems under specific scenarios. To explore these studies, the related literature has been systematically reviewed in this work. On the basis of the research gaps and the needs of industrial practices, future research directions in this field are also proposed.
Partial least squares structural equation modeling (PLS-SEM) is a modern multivariate analysis technique with a demonstrated ability to estimate theoretically established cause-effect relationship models. This technique has been increasingly adopted in construction management research over the last two decades. Accordingly, a critical review of studies adopting PLS-SEM appears to be a timely and valuable endeavor. This paper offers a critical review of 139 articles that applied PLS-SEM from 2002 to 2019. Results show that the misuse of PLS-SEM can be avoided. Critical issues related to the application of PLS-SEM, research design, model development, and model evaluation are discussed in detail. This paper is the first to highlight the use and misuse of PLS-SEM in the construction management area and provides recommendations to facilitate the future application of PLS-SEM in this field.
Over the past decade, electric vehicles (EVs) have been considered in a growing number of models and methods for vehicle routing problems (VRPs). This study presents a comprehensive survey of EV routing problems and their many variants. We only consider the problems in which each vehicle may visit multiple vertices and be recharged during the trip. The related literature can be roughly divided into nine classes: Electric traveling salesman problem, green VRP, electric VRP, mixed electric VRP, electric location routing problem, hybrid electric VRP, electric dial-a-ride problem, electric two-echelon VRP, and electric pickup and delivery problem. For each of these nine classes, we focus on reviewing the settings of problem variants and the algorithms used to obtain their solutions.
China is an early user of geothermal energy, and its direct use ranks first in the world. Recent national strategies and policies have enabled China’s geothermal energy industry to enter a new era with important development opportunities. This paper investigates the strengths, weaknesses, opportunities, and threats (SWOT) to China’s geothermal energy industry from political, economic, social, and technological (PEST) perspectives. SWOT–PEST analysis indicates that the resources, market, and technological foundation exist for the large-scale development of China’s geothermal energy industry. However, it experiences constraints, such as unclear resource distributions, incomplete development of government regulations, incomplete implementation of national policies, unclear authority between governmental administrative systems, and lack of uniform technical standards and codes. Therefore, future development strategies have been proposed to provide technical support and policy tools for geothermal energy development. The recommendations to ensure its healthy and sustainable development include improving resource exploration, rationalizing administration systems, enhancing policy guidance and financial support, and cultivating geothermal talent.
The use of engineering procurement construction (EPC) mode is currently a trend in hydropower engineering construction. The clarification of the internal relationship between hydropower EPC projects and the realization of synergy has great significance in improving management efficiency and implementation effect. In this work, a three-dimensional system and a system model of hydropower EPC project management synergy are constructed. The mechanism and factors that influence the degree of management synergy are analyzed on the basis of management synergy theory. Furthermore, the evaluation index system and the degree of synergy model are established, and grey relational analysis is utilized to identify the key factors that affect the synergy degree. Thus, this study aims to facilitate the hydropower EPC project management synergy, provide a quantitative method for synergy degree evaluation, and propose corresponding promotion strategies. Results show that the order degree of each subsystem presents a steady upward trend. Specifically, the order degree of the subsystem at the trial operation stage is low, which is the major restriction on the further improvement of the synergy degree of EPC project management. The key factors in improving the synergy level of hydropower EPC project management are mainly concentrated in the information and organization synergy subsystems, including the construction degree of information platform, the performance of functions, the timeliness of information transfer, and the functions of the information platform.
Design review (DR) is a product development (PD) activity used to inspect the technical characteristics of a design solution. Immersive virtual reality (IVR) technology enables the presentation of spatial information and interaction with 3D CAD models inside an immersive virtual environment (IVE). Such capabilities have shown the potential to mitigate the cognitive load needed for the visual perception of spatial information and, consequently, enhance design understanding and DR performance. Thus, an increasing number of studies have explored the effect of IVR technology on DR activities in different domains. However, determining when the implementation of IVR technology rather than a conventional user interface for DRs in mechanical engineering PD projects will be beneficial remains unclear. Hence, a conceptual DR experimental study was conducted to investigate the differences in the ability of engineering students to identify mechanisms and understand their functions when a design solution for a technical system is presented in an IVE by IVR technology and in a non-immersive virtual environment (nIVE) by a conventional user interface (monitor display, keyboard, and mouse). Data were collected by performing DR tasks and having participants complete a prior experience questionnaire, presence questionnaire, and mental rotations test. Findings of the study indicate that IVR does not support an enhanced ability of engineering students to identify mechanisms and understand their functions compared with a conventional user interface.
As part of general construction management, production planning and control is vital for successful project delivery. Numerous approaches supporting production planning and control exist in practice and research. However, the different approaches focus on distinct areas such as workflow stabilization or cost control, and no single system combines all the requirements of a holistic production management system. Varying production management systems can be explained by the unique characteristics of many construction projects. As an approach for the digital twinning in the construction industry, building information modeling (BIM) can help standardize production management through shifting the management system design toward the digital prototype. Previous scientific work has acknowledged this approach, thereby generating numerous concepts for using building information models within construction management approaches. However, BIM is often merely used as a parallel support rather than as an integral part of production management systems. To address this gap and in terms of research methodology, we follow a Design Science Research approach. Thus, we propose a new BIM-based production management system, which is characterized by a theoretical integration model for BIM and existing construction management techniques, and a methodology for applying these concepts in practice.
Performance measurement (PM) generates useful data for process control, facilitates communication between different sectors, and helps to align efforts on the most important aspects of the business. Thus, PM plays a key role in the management of projects and organizations. PM is also important in the implementation of lean production principles and methods, such as reducing the share of nonvalue-adding activities, increasing process transparency, building continuous improvement into the process, and benchmarking. Moreover, the adoption of the lean production philosophy requires changes in PM. Despite its importance, limited studies have been conducted on the use of PM systems for assessing the impact of lean production programs in construction projects. In addition, studies on how lean companies (or projects) use performance measurement and to what extent the indicators adopted reflect the result of actions that have been undertaken are limited. This study proposes a set of requirements in PM systems of construction projects from the perspective of lean production and a taxonomy of performance metrics for lean production systems. Five empirical studies have been carried out on construction companies from South America involved in the implementation of lean production systems. The scope of this investigation is limited to the construction projects as production systems rather than PM at the level of construction organizations.
Liquid Air Energy Storage (LAES) is at pilot scale. Air cooling and liquefaction stores energy; reheating revaporises the air at pressure, powering a turbine or engine (Ameel et al., 2013). Liquefaction requires water & CO2 removal, preventing ice fouling. This paper proposes subsequent geological storage of this CO2– offering a novel Carbon Dioxide Removal (CDR) by-product, for the energy storage industry. It additionally assesses the scale constraint and economic opportunity offered by implementing this CDR approach. Similarly, established Compressed Air Energy Storage (CAES) uses air compression and subsequent expansion. CAES could also add CO2 scrubbing and subsequent storage, at extra cost. CAES stores fewer joules per kilogram of air than LAES – potentially scrubbing more CO2 per joule stored. Operational LAES/CAES technologies cannot offer full-scale CDR this century (Stocker et al., 2014), yet they could offer around 4% of projected CO2 disposals for LAES and<25% for current-technology CAES. LAES CDR could reach trillion-dollar scale this century (20 billion USD/year, to first order). A larger, less certain commercial CDR opportunity exists for modified conventional CAES, due to additional equipment requirements. CDR may be commercially critical for LAES/CAES usage growth, and the necessary infrastructure may influence plant scaling and placement. A suggested design for low-pressure CAES theoretically offers global-scale CDR potential within a century (ignoring siting constraints) – but this must be costed against competing CDR and energy storage technologies.