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This is an account that should be heard of an important struggle: the struggle of a large group of experts who came together at the beginning of the COVID-19 pandemic to warn the world about the risk of airborne transmission and the consequences of ignoring it. We alerted the World Health Organization about the potential significance of the airborne transmission of SARS-CoV-2 and the urgent need to control it, but our concerns were dismissed. Here we describe how this happened and the consequences. We hope that by reporting this story we can raise awareness of the importance of interdisciplinary collaboration and the need to be open to new evidence, and to prevent it from happening again. Acknowledgement of an issue, and the emergence of new evidence related to it, is the first necessary step towards finding effective mitigation solutions.

In the construction industry, digitalisation has led to increasing efforts to improve construction management using digital visual management (VM) devices. Although the amount of research on digital VM (DVM) in the design phase and in the management of construction sites has also increased, its implementation during the production phase and by construction crews remains limited. The objective of this study is to explore the adoption of DVM in construction sites, assess construction workers’ experiences regarding digital and analogue VM devices, and understand the challenges that hinder the adoption of such devices. This study used a mixed method approach, combining qualitative and quantitative research. Data included visual site explorations, surveys of construction workers and crew managers, and unstructured interviews with site managers and development directors to assess the use of DVM devices in construction sites, the need for them and their current implementation. The findings showed that VM should be conveniently located near the job site instead of the office site, which is the current situation. Construction crews who experienced more production and schedule disruptions reported that VM supported their work, compared with crews that had fewer disruptions. VM devices on construction sites are analogue, and their usage continues to be in construction site management, which perpetuates information silos during construction projects. The findings of this study provide insights into the development and deployment of DVM devices on construction sites. Construction workers’ need for visual information close at hand is of interest to both scholars and practitioners in future research and development.

Purpose Prefabricated products are continually entering the building construction market; yet, the decision to use prefabricated products in a construction project is based mostly on personal preferences and the evaluation of direct costs. Researchers and practitioners have debated appropriate measurement systems for evaluating the impacts of prefabricated products and for comparing them with conventional on-site construction practices. The more advanced, cost–benefit approach to evaluating prefabricated products often inspires controversy because it may generate inaccurate results when converting non-monetary effects into costs. As prefabrication may affect multiple organisations and product subsystems, the method used to decide on production methods should consider multiple direct and indirect impacts, including nonmonetary ones. Thus, this study aims to develop a multi-criteria method to evaluate both the monetary and non-monetary impacts of prefabrication solutions to facilitate decision-making on whether to use prefabricated products. Design/methodology/approach Drawing upon a literature review, this research suggests a multi-criteria method that combines the choosing-by-advantage approach with a cost–benefit analysis. The method was presented for validation in focus group discussions and tested in a case involving a prefabricated bathroom. Findings The analysis indicates that the method helps a project’s stakeholders communicate about the relative merits of prefabrication and conventional construction while facilitating the final decision of whether to use prefabrication. Originality/value This research contributes a method of evaluating the monetary and non-monetary impacts of prefabricated products. The research underlines the need to evaluate the diverse benefits and sacrifices that stakeholder face when considering production methods in construction.

It is generally acknowledged that good-quality design is a prerequisite for good quality and productive construction work. One proposed measure to improve the quality of construction has been contractors’ involvement in the design phase, and this phenomenon has been studied by several researchers. However, such approaches have not adequately addressed how this involvement affects the quality of the design. In this study, the aim was to study the effects of the early involvement of contactors on design quality based on evaluating the design quality factors. A case study was used to collect data and content analysis to analyze structural drawings and design meeting minutes of a large-scale infrastructure project. Particularly, the focus was on gathering information on the quality of the design and how it was addressed in the design coordination. We combined this quantitative data with qualitative open-ended thematic interviews, including respondents who led and coordinated the design on both the client and contractor sides. Our findings suggest that despite the vast amount of design changes, contractors’ involvement and development work in the detailed design phase improved design quality and constructability. Our findings also suggest that the contractor’s involvement during the schematic design phase had a design-enhancing effect in the detailed design phase. This study contributes to our understanding of contractors’ valuable role in design quality.

Publisher Copyright: © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Building design and design management practices are beset by many problems to which satisfactory solutions have not yet emerged. The recognition of the Aristotelian legacy on design theorization has given rise to the proposition that the development of a new design concept that integrates the technical and social aspects of design might provide a general solution. This study aims to chart the intellectual history of the design discipline, clarify core design terms, concepts, and relationships, and propose a design model that integrates technical and social phenomena. An integrative literature review is a basis for the assessment and synthesis of representative literature and the construction of the new design model. The new design model, presenting the integrated design process structure for technical and social design activities, is the main contribution of this study. The model was constructed based on the identification of design theory core elements and relationships and the ancient design theories (the method of analysis and rhetoric).

The last planner system™ (LPS) is a production control method used in lean construction projects that has offered good results to construction companies in terms of improving labour productivity, increasing collaboration and the possibility for developing continuous learning. This short study contributes to LPS research on the reliability of promises and how parties perceive their effects on schedule and productivity. The study was conducted using a case study on an industrial construction project in which LPS had been in use since its start. Research data were collected using a semi-structured survey conducted online due to the pandemic. The study also utilized project progress data and measurement data from the LPS sessions. The most interesting result of the study was how little the LPS participants felt they had to compromise their goals. We also found how scheduling methods used in parallel with LPS can frustrate users and contribute to reducing its usefulness. Our findings can be used in further research in several ways, either by utilising the questionnaire we developed or by comparing our findings to other studies. We believe that practitioners using LPS will benefit from our results and can use them to address these shortcomings identified in future projects.

Building Design Management (DM) is challenging due to the fragmentation of project partners, the iterative nature of design and the tradition of informal management of designers. Therefore, many contractors do not trust the promises of designers and protect the construction schedule with schedule buffers that increase project lead times. To act upon this situation, several researchers have suggested using the Last Planner™ System (LPS) as a method for DM. Using two case studies, we present how the use of the LPS method as a tool for Daily Management (DAM) increases the reliability of the design and how, correspondingly, not using it can affect design reliability. So far, very little attention has been paid to the role of DAM in DM, and this short article seeks to provide new insights into this research gap for both researchers in the field and DM professionals. These early and exploratory results, despite the limited number of cases, can be utilised in further research as well as in practical project management, especially when the reduction of schedule buffers between construction and design is targeted

Digital twinning is a new approach to enhance the management of design, planning and construction operations. A construction digital twin aims to enhance the reality capture of ongoing operations using sensing technologies and AI functions to enable proactive process management. While a digital twin is clearly defined in the context of construction operations, where a digital replica is generated out of a physical site; a design digital twin lacks a clear framing as both twins are digital. This paper explores an approach to creating a design digital twin using agent-based simulation to mimic real BIM-based design projects. Accordingly, a digital replica is generated as an agent-based model. In addition, several KPIs are introduced to capture data related to BIM model dynamics. The results show that the suggested KPIs can increase the transparency of the design process, capture development dynamics at the level of BIM model elements, increase situational awareness among designers related to model development status, and identify higher clashing risk zones.

Publisher Copyright: © 2022 American Society for Engineering Management. The Critical Path Method (CPM), the Last Planner System (LPS) and location-based methods, such as the Line of Balance (LB), are discussed extensively in the technical literature about schedules. However, no discussion exists focusing on the differences and similarities of these methods in terms of their use in different countries. Using chi-squared and Fisher’s exact tests, this research compared three countries (Brazil, Finland, and United States) and the methods to evaluate both intra- and inter-country implementation to gain additional insights about their use. Results suggest statistically significant intra- and inter-country differences regarding how these methods are used, with a specific focus on mechanics in the countries, offering important information to address their various scheduling needs. The results reflect the current state of practice; engineering and construction managers should understand different ways of understanding scheduling. Such understanding can lead to more efficient communication with collaborators and when incorporating foreign teams in projects. The study identifies the need for further scientific explanation as to why these methods are used in the manner they are intra-country as well as adaptions made in inter-country relationships.

Low trust levels among project parties are generally believed to harm construction project performance, but the role of trust in the context of information flow and solving design quality problems (DQP) remains understudied. Whereas lean design management research highlights the importance of managing information flow, few studies have investigated the association between trust, information flow and DQP (or any combination thereof). This exploratory study investigates the association between trust and information flow in design projects and how these factors influence design quality. The paper presents a conceptual framework based on existing research on building design management and trust in a project context. The framework is elaborated on and validated using a single case study approach with multiple sites. The results indicate that even though the trust trend in the project is somewhat negatively connected to the overall amount of work and work in progress of DQP, increasing trust is not a prerequisite for solving DQP and that owners and contractors can have opposite opinions on the trust level. This study contributes to ongoing discussions about trust, information flow and design management and suggests that teams should focus on improving communication and collaboration to compensate for low trust levels.

Publisher Copyright: © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Decentralised, autonomous planning and control is a potential avenue of improvement in several fields, including construction. However, research on this topic, particularly involving the production crew viewpoint, remains scarce within the construction production management domain. This study explores the effects of decentralisation (and in contrast, effects of centralisation) for construction production planning and control (PP&C) from the combined perspectives of production crews and managers, and utilises these viewpoints to suggest improvements for PP&C practices. The study answers the following research questions: How do decentralisation/centralisation affect construction PP&C practices when considering both the production crew and manager perspectives? and Based on the aforementioned perspectives, how may construction PP&C practices overall be improved? To achieve holistic assessment, the research is conducted as a multi-method comparative case study using survey-based social network analysis (SNA) and semi-structured interviews. The results show that decentralised PP&C offers several benefits—such as improved transparency, conflict resolution, commitment, and lower stress—while allowing a proactive building of resilience, trust, ownership and autonomy for crews. In its current applied form, however, the approach does not fully reach the worker level. Regardless of the approach that is used, production crews perceive PP&C as decentralised, while managers perceive PP&C as having centralised structures. This gap between perceptions forms barriers for effective PP&C that must be properly addressed. Eight improvement suggestions are constructed to improve PP&C, that generally emphasise more deliberate decentralisation but that also indicate the necessity of partial central planning and control.

There is great disparity in the way we think about and address different sources of environmental infection. Governments have for decades promulgated a large amount of legislation and invested heavily in food safety, sanitation, and drinking water for public health purposes. In contrast, airborne pathogens and respiratory infections, whether seasonal influenza or COVID-19, are ad-dressed fairly weakly, if at all, in terms of regulations, standards, and building design and operation, pertaining to the air we breathe. We suggest that the dramatic growth in our understanding of the mechanisms behind respiratory infection transmission should drive a paradigm shift in how we view and address the transmission of respiratory infections to protect present and future generations from unnecessary suffering and economic losses. It starts with a recognition that preventing respiratory infection, like reducing waterborne or food-borne disease, is a tractable problem. See Additional URL below for 'free to read' PDF reprint.

There is substantial epidemiological evidence on the associations between cold weather and adverse health effects. Meteorological alarm systems are being developed globally, and generalized protective advice is given to the public based on outdoor exposure parameters. It is not clear how these shared outdoor exposure parameters relate to the individual-level thermal exposure indoors, where the majority of time is spent. We hypothesized a priori that there are opposite correlations between indoor and outdoor temperatures in residential apartments. Apartments were classified into 3 categories according to their response to declining outdoor temperature: under-controlled apartments cool down, controlled apartments maintain constant indoor temperature level, and over-controlled apartments warm up. Outdoor and indoor temperatures were measured in 30-min intervals in 417 residential apartments in 14 buildings in Kotka, Finland, between February and April 2018 with outdoor temperatures ranging from − 20.4 °C to + 14.0 °C. Different apartment types were present in all buildings. Floor and orientation did not explain the divergence. Indoor temperatures below the limit value + 20 °C by building code occurred in 26.2%, 7.9%, and 23.6% of the under-controlled, controlled, and over-controlled apartments, some in conjunction with increasing outdoor temperatures. Indoor temperatures above the limit + 25 °C occurred but were more rare. This proof-of-concept study demonstrates that while the home environment may be a source of thermal stress during cold weather, generalized advice for adjusting the heating may lead to paradoxical exposures in some cases. More elaborate conceptualizations of everyday thermal exposures are needed to safely reduce weather-related health risks using shared meteorological alarm systems. Electronic supplementary material The online version of this article (10.1007/s00484-020-01998-7) contains supplementary material, which is available to authorized users.

It is difficult to find a cross-industry comparison where the construction industry is not one of the worst performing industries. Countless studies demonstrates that the industry is lacking other industries in productivity development and safety. But are we actually comparing apples-to-apples, or, moreover, are there areas where construction industry is performing better than most industries? It is easy to show what does not work but it seems to be harder to show what works. This paper presents some early results of performance measures that large number of leading engineering and construction companies have agreed to measure performance on in the Finnish construction industry. We compare reliability, user experience, sustainability, productivity, and customer satisfaction. Based on this baseline progress in the industry will be followed and also compared to other industries. There are already some interesting points to be lifted, like schedule reliability in Finland seems to be higher than in studies in other countries. Another interesting observation is customer satisfaction and Net Promotor score, where construction industry scores higher than most other industries. Based on the performance measures the paper discusses about industry performance in general.

Continuous improvement depends on appropriate productivity measures. Productivity can be measured through time-motion studies but relies heavily on manual efforts and therefore contributes insufficiently to real-time awareness in dynamic environments such as construction. Indoor positioning shows potential determining shares of construction workers VA (Value-adding), based on Bluetooth Low Energy technology in real-time. Different studies show positive correlations between VA and productivity. However, it is unknown from location data how much workers engage in VA work while being present. Applying both methods simultaneously to one worker, this paper shows how to numerically quantify direct work (DW) and VA. Such combined data can show how much VA and DW occur when uninterrupted presence is detected while applying thresholds, indicating minimum durations spent inside work locations. Utilizing a small data sample enabled proof-of-concept testing and resulted in numerical quantifications of DW and VA. Preliminary findings show larger proportions of DW and VA when uninterrupted presence time is higher. Future research needs to enlarge the included data. If findings hold true, uninterrupted presence with higher thresholds could predict more accurate workers´ VA levels in real-time. The study also contributes to knowledge positively impacting construction by bridging workers’ behaviors on-site with monitoring technologies detecting movement

MEP (Mechanical, Electrical, and Plumbing) coordination is a challenging task in construction projects. Failing to properly manage the MEP activities can lead to consuming up to 60% of the total budget, as noted in literature. Previous studies have documented several challenges of MEP coordination; however, they did not focus on understanding different stakeholders' perspectives. Thus, in this research, we have analyzed the challenges of MEP coordination from different stakeholders’ perspectives taking the Finnish construction sector as a case. The study employed semi-structured interviews, web-based surveys, and experts’ workshops as means of data collection. In addition, we have also analyzed current practices for MEP coordination and presented possible ways to improve the MEP coordination in Finnish construction industries. The results showed significant shortcomings including non-accurate initial design plans, lack of trust between parties, unforeseen MEP cost at early phases, and unavailability of realtime progress monitoring tools. As a contribution, this study presented several challenges, especially in the regional context. Furthermore, this study also analyzed currently used MEP coordination practices in the Finnish construction market and presented suggestions for improvements. The findings of this study will help in the reduction of construction wastes, delays, and cost overruns in construction projects.

Construction projects need adequate planning to set a structure and direction for production, but simultaneously call for effective control to maintain the direction when something unexpected happens. Effective control is of utmost importance for takt production, which is especially vulnerable when disruptions occur. While previous takt production research has primarily focused on how to form a good takt plan, little attention has been given to how to control and continuously improve takt production systems effectively. Addressing the gap, this study inspects takt control through the lenses of failure modes and effects analysis (FMEA). First, we argue that takt control can be perceived through three different failure categories: failures within wagons, failures in handoffs, and failures in takt trains. We discuss the peculiarities of takt control through these categories and provide examples of failures with their respective failure mode(s) and possible control action(s). Second, we construct an FMEA-based framework for effective takt control that shows how to recover from failures and avoid them altogether. Future research may consider validating the failure categories and the framework through case studies or simulations, and examining their applicability in supporting digital takt production.

Continuous improvement requires visualizing process constraints which interrupt workflows. Production control from a management perspective often operates at lower levels of information granularity than required at operational levels to perform work without interruptions. If not controlled in detail, causes and effects of workflow interruptions remain unclear in environments of high complexity and non-standardized work. Workflow efficiency has been studied through work sampling or time-motion studies, estimating shares of direct work. However, few studies exist that show how to create digital representations of workflows and analyse them for interruptions, contributing to smoother workflows. The paper examines workflows of plumbing work from video footage. This video data is classified and analysed for frequency, causes, and effects of work interruptions. Results indicate that value-supporting activities caused the largest proportion of interruptions. Moreover, the proportion of non-value-adding activities increases when durations of interruptions rise. Based on the results, the paper contributes to further understanding of workflow interruptions in plumbing work. Finally, it provides suggestions on how to close gaps of information granularity between management and operational levels, through the development of simulation models and the application of automated data collection, contributing to developing digital twins of construction processes.

Funding Information: The research was conducted as part of the Aalto University’s research project “Building 2030 - industrialized construction“ which is funded by 19 companies operating in the real estate and construction sector. The Finnish Science Foundation for Economics and Technology has also financed the research. Earlier results have been published in a conference paper by Lavikka, R., Chauhan, K., Peltokorpi, A. and Seppänen, O. (2018) Fostering prefabrication in construction projects - case MEP in Finland in eWork and eBusiness in Architecture, Engineering and Construction, eds. Karlshoj, J. and Scherer, R. Taylor and Francis Group, London, UK. Proceedings of the 12th European Conference on Product and Process Modelling (ECPPM 2018), Copenhagen, Denmark, 12-14 September 2018. Publisher Copyright: © 2021, Rita Lavikka, Krishna Chauhan, Antti Peltokorpi and Olli Seppänen. Copyright: Copyright 2021 Elsevier B.V., All rights reserved. Purpose: Systemic innovations emerge and create value in an inter-organisational context. However, innovation studies rarely investigate the role of value creation and value capture among multiple organisations in successful innovation implementation. This paper aims to understand the role of value creation and value capture in the implementation of systemic innovations in construction which is by nature, an inter-organisational context. Design/methodology/approach: The empirical research focused on the barriers, enablers and opportunities for value creation and value capture of the Finnish construction project parties when trying to implement mechanical, electrical and plumbing (MEP) prefabrication, which is a systemic innovation. Data were collected through interviews, observations and action workshops. Findings: The empirical study identified interaction patterns on how social, political, technical and economic barriers lead to uneven value capturing, lack of value-based procurement and unclear value creation between MEP design and installation. They hinder the implementation of MEP prefabrication. The results point to enablers leading to fairly shared value to all parties, procurement of value and collaborative value creation, thus increasing the usage of MEP prefabrication, a systemic innovation. Originality/value: The study adds new knowledge by demonstrating that the identification of barriers and their interaction with enablers and opportunities for value creation and capture lay a baseline for suggestions on how to implement a systemic innovation. This study stresses the importance of enabling value creation and capture for all construction project parties when implementing a systemic innovation.

In the era of customer-driven and digitalized businesses, the construction industry has still demonstrated inadequate performance development. This research aims to disentangle the industry’s current problems and present justified paths toward sustainable improvement. Following the design science research approach, the paper develops a conceptual framework about the path toward the systemic transformation of the construction industry. We first argue how current efforts to improve construction system are often limited to changes in sub-systems, namely in a) products, b) processes, c) organizing and people, d) information systems, or e) value creation models, therefore lacking a systemic approach needed for significant and sustainable improvements. We then propose a framework that underlines the need to simultaneously develop all the identified five sub-systems to achieve successful transformation. Three cases are presented as partial solutions to such systemic innovations. The paper provides new insights into how a systemic approach could be utilized when transforming the construction industry. More specifically, takt production is identified as one key driver for systemic change. The theoretical contribution lies in the identified five sub-systems and their parallel development as a source for sustainable transformation. However, the paper is conceptual and limited to three partial cases. More empirical research is needed to validate the framework and to specify the most effective transformation paths.

Takt production is the most recent iteration of location-based production planning and control methods, adopting insights from lean construction and manufacturing operations management literature. In this research, we aim to advance the discussion between these domains further, especially considering the client’s viewpoint. We approach takt production as a form of a project’s operations strategy, allowing an explicit connection between client value-creation, production flow, and takt planning and control. Five key performance indicators are proposed to aid the client’s understanding in assessing (and challenging) the effectiveness and value-creation capability of a specific takt production system. Furthermore, the approach is illustrated by applying it to a master planning phase of a large hospital project. The study has implications for clients and other stakeholders to evaluate their capability to operate with takt production from the lenses of valuecreation and production flow. We also hope that the study encourages scholars and practitioners to engage in further discussion with the nature of takt production, observing it from various theoretical and practical viewpoints.

Despite recent developments in construction design management, too much variability still occurs in design processes. Batch size (BS) and throughput time (TT) reduction are recurring concepts in the lean construction literature related to the Last Planner© System (LPS). These three parameters are often used to reduce variability and improve flow and reliability in work processes. Some have attempted to reduce design variability through lean design management (LDM) and agile methods, but very few studies have analysed the interaction of these parameters in the design process. The purpose of this study is to investigate these variables and their interactions. Design process stability and reliability were measured over nearly two years in this study by using three parameters. According to the results, design teams with smaller BS’s of design tasks and higher percentages of planned tasks completed also had shorter design task TT’s. Designers may use these findings to improve their workflow monitoring and as a novel addition to LDM and coordination metrics.

Renovation projects are a special type of construction projects. The unique features of renovation projects make production control challenging, as they often cause a great deal of variation, resulting in waste in production and reducing profitability. Takt production has been applied to renovation, but its specific suitability and benefits in renovation projects have not been studied widely. This paper describes a design science study that i) examines the suitability of takt production in renovation projects through literature and interviews, ii) designs a process model for applying takt production in renovation projects, and iii) applies and validates the designed process model in a case project. The findings imply that takt production can benefit renovation projects. The study highlights the significance of fulfilled prerequisites and well-managed supporting functions in takt production. If these requirements are not fully met, the significance of proactive problem-solving in production control and collaborative practices increases.

Takt production is gaining increasing visibility in the construction industry. To further improve the current takt production practices, visual management tools could offer improved efficiency in the production control phase. However, the effects of visual management in takt control setting have not yet received much attention in research. This study aimed to investigate the effects of various visual tools in a takt production setting to gain knowledge on how these tools could aid takt control efficiency. The research utilized a design science research approach to create visual management tools and iterate them based on feedback. Interviews, site observation, and takt progress tracking were used to evaluate the implemented tools. The findings indicate that workers on site want to be more aware of the production plan, and information helps them to work in the right location at the right time. To help workers, visual management tools need to recognizable, explicit, and contain correct and up-to-date information. However, there are cultural issues related to implementation, especially on the need for information going through foremen to crews.

Renovation and relocation of underground utilities and renovating the streets are essential to maintain urban infrastructure. In cities, street reconstruction projects cause substantial harm to citizens in the form of traffic jams, noise, and poor access to businesses. Although some harm is unavoidable, the harm could be mitigated, for example, by decreasing overall construction durations. We used design science research to diagnose the current state of street reconstruction projects in the City of Helsinki and to develop a new model aimed at shortening project durations. The diagnosis was made based on interviews, workshops, observations, a survey, and an archival study. The identified key root causes of problems were lack of collaboration and inflexible contract forms in projects with high uncertainty. The new model was co-created with stakeholders participating in these projects, including a collaborative development phase, a shared situation picture among actors, and joint risk analysis of all parties. The study's key contribution was the way to use design science research to start a lean implementation in a challenging project type with multiple public stakeholders. The City of Helsinki will pilot and further develop the model in three street reconstruction projects.

Motivated by the European Green Deal framework, an ambitious 30-years long renovation strategy has been established in Estonia. This renovation strategy requires a substantial increase in the annual renovation capacity. New capabilities in terms of industrialization and digitalization of sustainable renovation processes need to be promoted. This explorative research aims to identify and understand existing practices, main barriers, and opportunities to industrialize and digitalize sustainable renovation of existing apartment buildings. Interviews and secondary data sources are used for data collection and analysis. Still many barriers exist, and more research and development in core elements of the industrialized renovation of apartment buildings is required. For example, further standardization of renovation products and processes is needed. Also, digitalization and automation of industrialized renovation of apartment buildings were the least developed core element.

Vertical logistics systems are important for enhancing production performance in highrise buildings (HRBs). However, researchers studying vertical logistics have focused on examining the flow of individual resources in isolation. Only a few studies adopt a holistic approach to optimizing the flow of resources. For example, research on the combined effect of the number, characteristics, and rules of elevators uses and break rooms' location on the production system's performance remain scarce. Methods and tools like agentbased modelling (ABM) and simulation could be used to study and predict vertical logistics systems' performance holistically. This research uses hypothetical strategies to investigate opportunities to enhance performance and develop more effective vertical logistics systems. The proposed agent-based model and simulation is validated with a simple, hypothetical takt plan. The simulation results show that the logistic system's performance varies when changing parameters like the number of elevators and the location of break rooms. This research's main contribution is a new way to study these systems and potentially enhance their performance. Furthermore, possibilities to maximize performance and remove logistical bottlenecks are suggested.

Purpose Although prior studies have noted the importance of trust for project performance, research remains scant on describing the role of trust when using lean design management (LDM) in projects. The purpose of this paper is to explore the connection between LDM and interpersonal trust in solving construction projects’ design management problems. Design/methodology/approach A qualitative study was conducted that included 29 trust- and LDM-themed semi-structured interviews in the USA (California), Brazil and Finland; 11 focus group discussions were also organized to validate the interview findings. Findings The study reveals how LDM contributes to solving design management problems through two distinct but interconnected mechanisms: improved information flow; and improved trust among project team members. A conceptual framework was crafted to illustrate the mechanisms in building trust by means of the social domain of LDM concepts. Research limitations/implications The conceptual framework requires testing through an international survey or through multiple case studies. Practical implications The results indicate that design management would benefit from trustful environments and that trust may be the catalyst for actors’ engagement with LDM. Managers in charge of design within projects can use the conceptual framework when selecting the appropriate LDM tools, which should include both the social and technical domains. Originality/value The study emphasizes the importance of the social domain of LDM concepts. Previous studies have focussed on information flow aspects of LDM but have overlooked the value of interpersonal trust in solving design management problems.

Funding Information: This research was supported by the Estonian Centre of Excellence in Zero Energy and Resource Efficient Smart Buildings and Districts , ZEBE, grant 2014-2020.4.01.15-0016 funded by the European Regional Development Fund and by the Estonian Research Council (grant No. COVSG38 ). Publisher Copyright: © 2021 The Authors A new design method is proposed to calculate outdoor air ventilation rates to control respiratory infection risk in indoor spaces. We propose to use this method in future ventilation standards to complement existing ventilation criteria based on the perceived air quality and pollutant removal. The proposed method makes it possible to calculate the required ventilation rate at a given probability of infection and quanta emission rate. Present work used quanta emission rates for SARS-CoV-2 and consequently the method can be applied for other respiratory viruses with available quanta data. The method was applied to case studies representing typical rooms in public buildings. To reduce the probability of infection, the total airflow rate per infectious person revealed to be the most important parameter to reduce the infection risk. Category I ventilation rate prescribed in the EN 16798-1 standard satisfied many but not all type of spaces examined. The required ventilation rates started from about 80 L/s per room.Large variations between the results for the selected case studies made it impossible to provide a simple rule for estimating the required ventilation rates. Consequently, we conclude that to design rooms with a low infection risk the newly developed ventilation design method must be used.

Takt production has recently received increased attention in both the construction industry and academia. However, the research on takt production has focused on documenting single successful cases, while attempts to holistically explore the impact of takt production on construction production flow are scarce. To address this knowledge gap, this study aimed to build a theoretical model of how takt production contributes to construction production flow. A qualitative multiple-case study was conducted to validate propositions based on a literature review, and the results were discussed and synthesized in the form of a theoretical model. The findings indicate that while takt production is a viable method to increase flow, it requires significant effort in terms of planning, control, and continuous improvement. While having a positive impact on process flow (location flow), the effects on operations flow (trade flow) are contradictory. The study has implications for further comprehensive evaluation of the effectsof takt production on construction production flow while facilitating more predictable, systemic implementation of takt production across projects.

Logistics management plays an essential role in supporting the primary activities in manufacturing industries. Similarly, in the construction industry, logistics operations are a crucial part that directly influence the construction operations. Construction operations management requires various stakeholders to collaborate through effective communication and prompt information sharing. However, logistics management in construction is often challenged by insufficient information management, lack of formalized information standards and poor information interoperability among heterogeneous systems. Semantic Web technologies advance information management support and improve information interoperability. In this research, we present a domain-level ontology as a common information reference for standardizing and integrating construction logistics information, and finally to improve the efficiency and transparency of logistics information management. The proposed ontology provides information interoperability between logistics management and construction workflow management. The ontology was evaluated by automatic consistency checking and answering the competency questions (CQs) via SPARQL queries. Furthermore, we used actual schedule and material delivery data of a construction project to evaluate the proposed ontology to see if it could support the material kitting logistics practice. We provide a valid ontology that is able support the logistics information management for the construction. The research is limited to providing a single example application of the ontology. Future research should focus on extending the ontology for different specific solutions to yield standardized information management for construction operations.

During the rapid rise in COVID-19 illnesses and deaths globally, and notwithstanding recommended precautions, questions are voiced about routes of transmission for this pandemic disease. Inhaling small airborne droplets is probable as a third route of infection, in addition to more widely recognized transmission via larger respiratory droplets and direct contact with infected people or contaminated surfaces. While uncertainties remain regarding the relative contributions of the different transmission pathways, we argue that existing evidence is sufficiently strong to warrant engineering controls targeting airborne transmission as part of an overall strategy to limit infection risk indoors. Appropriate building engineering controls include sufficient and effective ventilation, possibly enhanced by particle filtration and air disinfection, avoiding air recirculation and avoiding overcrowding. Often, such measures can be easily implemented and without much cost, but if only they are recognised as significant in contributing to infection control goals. We believe that the use of engineering controls in public buildings, including hospitals, shops, offices, schools, kindergartens, libraries, restaurants, cruise ships, elevators, conference rooms or public transport, in parallel with effective application of other controls (including isolation and quarantine, social distancing and hand hygiene), would be an additional important measure globally to reduce the likelihood of transmission and thereby protect healthcare workers, patients and the general public.

The construction industry is claimed to suffer from low productivity often caused by its complex, individualistic and unstructured nature. The construction workers’ situational awareness (SA) is an insufficiently investigated and overlooked perspective in current project and production management literature to increase productivity in construction projects. This paper discusses the role of construction workers in planning and control of production and the possible impact of SA for on-site processes integrating knowledge and expertise from construction workers. The paper reviews the literature concerning construction workers’ on-site situation, integration in production planning and control processes and the possibilities for empowering workers with SA. Providing real-time situational data can empower workers to make better decisions based on accurate, transparent, structured and trustworthy data. It is concluded that a better understanding and availability of the project information and progress can free up workers' workload, to focus their capacity on the task delivery. This will ultimately lead to a boost in productivity on-site. Furthermore, the paper opens avenue for further research and how to capture the current state of on-site SA of construction workers through a methodical approach including quantitative and qualitative methods.