<![CDATA[This study aims to identify the factors contributing to the high rate of first-attempt delivery failures in Lion Parcel's last-mile delivery operations in the city of Bandung, which are caused by various operational obstacles faced by couriers in the field. The objective is to examine how Commercial Time Window, Delivery Time Constraints, and Traffic Congestion affect the first-attempt delivery success rate, while also testing whether Fleet Allocation Management acts as a mediating factor among these variables. This study employs a quantitative approach with an explanatory research design. Given the relatively small population size, the entire population was used as the sample (census/saturated sampling), consisting of 90 respondents made up of active motorcycle couriers and van drivers. Primary data were collected directly through a closed-ended Likert-scale questionnaire and subsequently processed using the Structural Equation Modeling–Partial Least Squares (SEM-PLS) method with the aid of SmartPLS 4 software. The structural model testing results show that Delivery Time Constraints and Traffic Congestion both have a positive and significant effect on Fleet Allocation Management, whereas Commercial Time Window shows no significant effect. Meanwhile, in testing the direct effects, all three obstacle variables, together with Fleet Allocation Management, were proven to have a significant effect on the first-attempt delivery success rate. In terms of mediation testing, Fleet Allocation Management was proven to successfully bridge the effects of Delivery Time Constraints and Traffic Congestion on delivery success, but was unable to mediate the effect of the Commercial Time Window constraint. This indicates that the issue of the commercial acceptance time limit (commercial time window) cannot be resolved solely through fleet management in the field; rather, improvements are needed in the dispatch work system at the warehouse that are more preventive in nature.]]>
