Lean-based analysis and improvement of equipment fleet utilisation in asphalt construction: a value stream mapping case study

Efficient fleet utilisation is critical to asphalt paving productivity, yet operations often suffer from truck queueing, idle time, dispatch variability, and reactive coordination. This study applies Value Stream Mapping (VSM) to diagnose these inefficiencies and develop a future-state workflow through a case study of a major asphalt contractor in Western Sydney, Australia. Semi-structured interviews were triangulated with workflow records, dispatch information, and process-time measurements. The current-state map captured 657 min of workflow, comprising 54.5% value-adding, 24.0% necessary but non-value-adding, and 21.5% non-value-adding time. Key losses included 45–60 min of truck marshalling, 15–30 min of paid waiting, 5–15 min of site queueing, and approximately 55 min of paver starvation per operational round. Dispatch logic, process synchronisation, and communication-intensive control were identified as major causes of inefficiency. A future state based on pull dispatch and production levelling was assessed using deterministic flow balance. At 214 t/h paving demand, 25 t truck payload, and 185 min cycle time, the balanced dispatch interval is about 7.0 min, requiring 27 trucks under the stated assumptions. The study positions VSM as a quantified diagnostic foundation for subsequent simulation, digital-twin, or optimisation-based validation.