How does the application of advanced project management techniques in civil engineering operations contribute to the efficient and effective completion of complex infrastructure projects? In your response, delve into the key project management frameworks, such as Agile, Lean Construction, and the Project Management Body of Knowledge $($PMBOK$),$ and analyze their specific roles in optimizing project workflows and minimizing waste. Discuss how these methodologies integrate with various phases of the project lifecycle, including initiation, planning, execution, monitoring, and closure. Explore the significance of stakeholder engagement, communication strategies, and conflict resolution in maintaining project momentum and addressing potential issues proactively. Furthermore, examine the impact of digital tools and software, such as project management information systems $($PMIS$),$ on enhancing decision$-$making processes, resource management, and schedule adherence. Consider the challenges faced in adapting these techniques to diverse project environments and scales, and provide insights into how continuous improvement practices are implemented to refine operational efficiency and project outcomes over time.