Automated Guided Vehicles (AGVs) and Autonomous Mobile Robots (AMRs) are being applied more and more frequently in a wide range of use cases. Following the general trend of decentralisation of control structure in the Industry 4.0 paradigm, this paper analyses the application of auction algorithms to solve the robot task assignment problem. We focus on the use of mobile robots in production environments with a high level of uncertainty which places hight demand on the flexibility of the online scheduling architecture. A sequential single-item (SSI) auction algorithm is validated for a real-world use case where multiple mobile robots supply car bodies to manual rework stations in a paint shop application using simulation. The optimization objective of such an algorithm is discussed in regards to the examined use case.