Capturing the Full Complexity of Postdisaster Freight Disruptions: An Application of the Theory of Constraints

This paper aims to investigate the mechanisms underlying freight disruptions and to capture the full complexity of a postdisaster freight system. Qualitative data were collected through 20 semistructured interviews with key informants in Aotearoa New Zealand’s fresh fruit and vegetables sector. The interview data were used to conduct a root cause analysis and build a Current Reality Tree (a tool prescribed by the theory of constraints). This diagnostic map captures the multifaceted reality of postdisaster transportation disruptions and the intricate sequence of interconnected events and constraints having an impact on the performance of a freight system. Thirty-two constraints affecting the functionality of freight transportation, nine root causes, four ultimate impacts on freight performance, and 42 cause-and-effect relationships between these various system components were identified. These findings show that building freight resilience requires a holistic and concerted approach that includes policy development as well as business and operational adjustments. This paper also expands the theory of constraints beyond its existing boundaries by applying it to freight transportation. In contrast to the existing literature that commonly uses mathematical modeling to study transportation complexity, this research presents a qualitative and rich depiction of the reality and innerworkings of freight disruptions. The results are immediately relevant and provide concrete explanatory and predictive insights for practitioners and policy makers.