## 5 Discussion  
The results indicate that machine guidance technology significantly improved excavation efficiency, primarily by reducing unnecessary relocation and enhancing the accuracy of each excavation cycle. The 27.3% reduction in excavation time and the 16.2% decrease in excavation cycles highlight the impact of real-time feedback on operator behavior, enabling more precise and continuous excavation. Furthermore, the relocation analysis suggests that frequent repositioning negatively impacted overall efficiency. The operators using the conventional method had to reposition twice as often as those using MG, largely due to manual verification of excavation depth and the need for corrective action. This additional movement contributed to the increased cycle time and disrupted the excavation workflow. Another critical factor influencing excavation performance is the fill factor. The higher average fill factor score (3.47) for the MG excavation compared with the conventional excavation (3.04) demonstrated that the MG enabled operators to achieve more consistent and optimal bucketloads per cycle. This improvement was associated with reduced occurrence of under-ex excavation, minimizing unnecessary corrections and rework. From a practical standpoint, these findings suggest that machine guidance systems can enhance not only excavation speed but also the consistency and accuracy of operators' actions. The structured excavation pattern observed in the MG excavation further supports this, showing that real-time feedback can promote a methodical approach that reduces unnecessary variation in excavation depth. A noteworthy field observation emerged when the operator, having seemingly completed Footing #1 using the conventional method, proceeded to Footing #2 but was later required to return to Footing #1. A subsequent manual survey revealed that the target depth had been incorrectly met, necessitating additional excavation and backfilling. This rework scenario represents a common challenge in contemporary construction settings, where survey personnel are not always available to carry out continuous on-site measurements. For instance, in this study, the surveyor was occasionally occupied with tasks such as operating a small compactor, limiting the frequency and immediacy of feedback provided to the excavator operator. Without real-time feedback, operators may proceed with lower confidence, potentially leading to over- or under-ex excavation that becomes apparent only when a surveyor is again able to check the depth. By contrast, the MG in this study offered continuous real-time feedback, enabling operators to verify depth on the spot and make immediate corrections, thereby reducing the likelihood of discovering errors long after moving on to a subsequent footing. This improvement is especially relevant under labor-constrained conditions, where surveyors must multitask and their intermittent availability delays feedback. Consequently, MG not only streamlines excavation but also mitigates the need for rework cycles and travel between multiple footings, addressing a practical limitation in construction sites where human resources are stretched thin. These findings suggest that the real-time feedback afforded by MG can substantially reduce operator uncertainty and improve overall workflow continuity, even in the face of limited on-site survey support. Overall, this study demonstrates that MG can improve excavation efficiency by reducing relocation frequency, optimizing digging cycles, and enhancing the accuracy of excavations. These benefits highlight the potential of MG to streamline excavation operations, reduce dependency on labor, and boost overall site productivity. Future studies should further explore the impact of MG on fuel consumption and operator fatigue to provide a more comprehensive understanding of its benefits in construction applications. The current results also showed that the real-time feedback provided by MG significantly improved excavation efficiency.