The aim of the study is to determine whether and how unpredictable factors impact on the uncertainty structure in the management of logistics processes.

The Delphi method was used in the first phase of the study. 40 experts in the field of logistics management, supply chain management, risk and efficiency of logistics processes were selected. In the second phase of the study, the structure of experts' responses was analysed and the Spearman rank correlation indicators between the indicated unpredictable factors and the consequences for the management of the logistics processes were determined.

During the study, unpredictable factors were identified that had the greatest impact on the structure of uncertainty in the management of logistics processes. In terms of probabilistic uncertainty, randomness was primarily indicated. In terms of stochastic uncertainty, most indications were reported for an unknown source of origin. The main sources of unpredictable factors from outside and inside the process were then identified. The most important uncertainty from the point of view of the logistics process was also determined. The uncertainty has been found to have implications for the management of the logistics process in terms of cost, time, and quality.

The obtained results identify unpredictable factors determining the uncertainty structure in the management of logistics processes. Respondents identified the most common internal and external sources of unpredictable factors. Additionally, uncertainty was found to have implications for the management of the logistics process in three key decision areas - cost, time, and quality.

The added value of the paper is the identification of the key unpredictable factors impacting on the uncertainty structure in the management of logistics processes.