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The COVID-19 pandemic caused significant societal changes and altered how much of the construction industry operates. This study investigates the impacts of pandemic-related changes, how these changes may apply to different companies, and which changes should continue post-pandemic.

We aim to identify pandemic-driven changes that have affected the construction workplace and the advantages and challenges associated with them. We then make recommendations for what could and should endure through the pandemic and beyond, and under what circumstances. To achieve this objective, we conducted both qualitative and quantitative analyses of 40 semi-structured interviews with US-based construction professionals.

Identified through these interviews were 21 pandemic-driven changes across six categories: management and planning, technology, workforce, health and safety, supply chain, and contracts. This study noted both positive and negative impacts of the changes on cost, schedule, productivity, collaboration, employee retention, flexibility, quality, and risk mitigation. Participants indicated that some changes should remain after the pandemic and others (e.g. select safety measures, schedule adjustments) should be temporary.

By incorporating these lessons learned into recommendations, the findings of this study will help businesses identify and implement the most appropriate improvements for their organizations. The findings also provide policymakers with valuable insights on how to promote innovation in the construction industry and potentially enact more effective policies during crises to drive long-term improvements.

This study aims to model power demand and energy consumption of fused filament fabrication (FFF) for carbon fiber-reinforced polyether-ether-ketone (CFR-PEEK) based on a material addition rate (MAR), which is affected by process parameter changes in an FFF machine. Moreover, a virtual additive manufacturing (AM) plant handling multiple FFF machines and part designs is simulated to compare the energy and production dynamics of operational strategies that treat part orders differently based on their inherent MAR.

A full-factorial design of experiments considering major FFF parameters (i.e., layer thickness and printing speed) is planned to fabricate CFR-PEEK samples for each process parameter combination. Then, the MAR of each process parameter combination is calculated to derive regression models for average power demand and total energy consumption. Furthermore, a discrete-event simulation model for a virtual AM system of aircraft parts is built to analyze changes in power demand and energy consumption along with order lead time and production volume under three operational strategies (i.e., higher MAR first-out, first-in-first-out, and lower MAR first-out).

The MAR of FFF for CFR-PEEK plays a key role in energy dynamics in which a decrease in energy consumption dominates over an increase in power demand as the MAR increases. Furthermore, preferentially processing parts with a higher MAR in the AM system is the most beneficial strategy in both energy consumption and productivity.

The findings from this study show that the energy performance of CFR-PEEK applications in FFF should be understood with the MAR of an AM system because the impact of AM complexity on energy performance can be operationally controlled by managing the MAR of part orders for the entire AM system.