An integrated coordination framework for construction procurement: Examining early supplier involvement through agent-based modeling

Construction projects rely on complex stakeholder networks, where coordination across design and construction phases is critical to performance. Despite decades of collaborative procurement frameworks, supplier expertise is integrated late in the design process, and the behavioral mechanisms linking procurement conditions to project outcomes remain poorly understood. This fragmentation generates coordination failures that manifest as rework, RFIs, constrained innovation, and declining workflow continuity. Existing literature examines procurement structures, stakeholder behavior, and project outcomes largely in isolation. Key drivers such as risk perception, supplier participation, and collaboration intensity are rarely formalized as measurable, dynamic variables throughout the project lifecycle. As a result, the mechanisms through which governance conditions and coordination timing jointly influence performance and innovation adoption remain unclear. This study examines how procurement structure, governance conditions, and stakeholder behavior interact within a dynamic system that shapes project performance. It develops and evaluates an Integrated Coordination Framework (ICF), centered on a Central Coordination Agent (CCA), to structure early supplier engagement, compensation conditions, and coordination across the design lifecycle. A mixed-methods design integrates industry interviews with an agent-based simulation model in AnyLogic. Interview data were thematically coded and translated into agent decision rules through structured coding-to-model mapping. The model was evaluated using a four-stage validation framework: internal verification, expert-based mechanism validation, pattern validation, and quantitative benchmarking using the Wilcoxon signed-rank test. Four key findings emerge. First, procurement structure creates the conditions for improved performance, but governance influences whether those conditions translate into improved outcomes. Under ICF, projects achieved 75% innovation adoption, 80% fewer Requests for Information (RFIs), and stable capacity utilization (~88%), compared to 25% innovation adoption, full RFI accumulation, and declining capacity utilization (~75%) under fragmented procurement. Second, the Central Coordination Agent improves performance by shifting coordination and issue resolution upstream into the design phase, where conflicts can be addressed while decisions remain flexible. Under ICF, this earlier resolution process reduced RFI generation and stabilized construction workflow conditions. In contrast, low early redesign activity and limited RFI volume under typical procurement can create a false sense of effective coordination, as unresolved issues are deferred to later construction stages, where resolution becomes more disruptive, increases the volume of RFIs, and reduces available capacity. Third, GMP timing operates as a governance constraint rather than a coordination variable. Once GMP is established, behavior shifts from collaboration to cost protection, regardless of the quality of prior coordination. Fourth, the highest-impact lever lies in the middle governance layer, defined by three conditions: clear compensation for early engineering work, formalized supplier decision authority, and relational continuity across project portfolios. This study contributes to procurement governance and stakeholder coordination literature while providing foundational insights relevant to transaction cost economics in construction procurement. Methodologically, the study offers a replicable mixed-methods framework for examining procurement as a dynamic behavioral system. In practice, the simulation tool enables procurement managers to identify which governance parameters limit performance before coordination failures become visible, allowing targeted intervention at the root cause rather than a reactive response. More broadly, engaging supplier expertise early through structured coordination and supportive governance leads to more innovative outcomes and stronger long-term stakeholder rela ionships, and the Integrated Coordination Framework is designed to enable this opportunity.