The Last Planner® system (LPS) has witnessed a major shift in implementation at the onset of Coronavirus disease 19 . Governed by maintaining social distancing and many other safety restrictions, some construction practices including LPS implementation are now taking place in the virtual environment. However, potential challenges and enablers of implementing LPS in such an environment are yet to be investigated. This paper presents a framework based on lean philosophy and aims at successful implementation of LPS in a virtual environment. The framework calls for embracing a strong lean culture in the virtual work environment. The study also seeks to outline the challenges and enablers of this implementation. The framework was tested on a construction project through an expert panel. Results show that the framework is promising, and that although COVID-19 inflicted many challenges, it also had some positive impacts on LPS implementation. The framework will help practitioners and managers adopt a systematic approach from initiation to implementation of LPS in a virtual environment.

The construction business is an ever changing industry facing increasingly bigger challenges, complexity and above all fierce competition. Contractors, in particular those managing fleet of construction equipment, have to cut their margins, increase the efficiency of their work force and assets, and control their total cost of ownership (TCO) to ensure an acceptable return on investment (ROI). As such, the business evolved in many ways to be cost-efficient. For instance, construction equipment manufacturers have focused on optimizing engine productivity, hydraulic versatility, and mechanical robustness, among many others. However, recent trends segued into delivering smart machines capable of reporting and adjusting equipment operators' behavior to achieve a better on-site fleet performance. This was made possible through the Internet of Things (IoT) and visualization tools by instrumenting construction equipment and devising advanced technological and on-board sensory systems as well as allowing the transfer of relevant information over a shared network within a 3D environment. The objective of this paper is thereby twofold: (1) shed light on the latest approaches developed from tracking systems, load weighing systems, onboard operator assists to help equipment operators in spatial navigation, and (2) examine current virtual systems used to interactively visualize instrumented fleet of equipment and provide proactive on-site monitoring. The review revealed that there is substantial room for improvement and adoption of new tools targeted at reducing inefficiencies, improving fleet productivity, and producing higher quality results, in less time and with less effort.

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Successful realization of construction activities requires simultaneous integration of various resource input flows, giving rise to considerable sources of flow variability. Such variability might manifest as schedule variations which jeopardize the project performance, especially when using deterministic scheduling. Current scheduling techniques fail to efficiently tackle variability and rely on deterministic approaches. Therefore, this study fills the gap by developing a Discrete Event Simulation model, where activity durations are modeled using beta distributions and Program Evaluation and Review Technique assumptions. By applying the Spearman correlation coefficient, activities with higher influence on the schedule are identified, highlighting where to reduce variability. An application example was conducted involving a Critical Path Method (CPM) network containing eleven activities. Two types of waste emerging due to variability are identified as waiting time and variation gaps. Out of the eleven activities in the example network, two sets of critical activities are identified. Results reveal that an 80% reduction in variability in these critical activities leads to a 51.9% increase in likelihood of completing the project on schedule, 30% decrease in waiting time, and 28.6% decrease in variation gap. An important implication of this research is that near critical paths could become critical based on the amount of variability contained in the activities lying on each path. Acquiring such information early on during planning provides proactive, eye-opening insights into potential problematic scheduling areas. The study's contribution includes investigating the variability effect on two types of waste in production and providing project planners with a stochastic approach to manage the hidden waste in production systems; This is a pre-published version

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