Humanitarian supply chains (HSCs) operate under severe time constraints and uncertainty, where delays in aid delivery can result in prolonged suffering and loss of life. This dissertation explores how lead-time effectiveness—a critical performance outcome—can be enabled in HSCs through integration between humanitarian organizations (HOs) and donors. Performance management and information systems are proposed as mechanisms supporting this integration during disaster preparedness. This dissertation employs a mixed-methods approach, combining systematic literature reviews, multiple-case studies, and survey-based empirical analysis. Five appended papers collectively address four research questions by (1) conceptualizing lead-time effectiveness holistically, (2) explaining integration challenges and mechanisms through agency theory, (3) adapting and applying performance management for integration, and (4) examining how information systems influence integration in performance management. Key findings reveal a holistic conceptualization of lead‑time effectiveness as lead‑times across humanitarian supply chain actors, resources, and activities planned in the disaster preparedness stage and enabled in the disaster response stage, contributing to timeliness, reliability, accuracy, and beneficiary satisfaction. This dissertation also develops a dictionary of performance metrics for lead-time effectiveness, so HOs and donors can define and measure them. The application of these metrics depends on HOdonorintegration. Integration remains challenging due to agency assumptions, including self-interest, bounded rationality, and goal conflicts. Agency theory explains these challenges and provides a basis for identifying mechanisms to address them. One mechanism is performance management, which supports integration through five activities: selecting performance variables, defining metrics, setting targets, measuring, and analyzing/acting. An adapted performance management framework for HSCs is proposed, emphasizing disaster preparedness and providing recommendations. Another mechanism is information systems, which support integration in performance management: characteristics (e.g., standardization) and capabilities (e.g., adaptability) significantly influence information for joint activities, whereas information flow remains constrained by, e.g., access restrictions and resource limitations. Suggestions include shared data formats, joint reporting templates, and staff training. Together, these contributions develop an updated conceptual framework and a pathway showing how performance management and information systems support integration and enable lead-time effectiveness in humanitarian supply chains, offering theoretical and practical implications to strengthen disaster preparedness for a better response.