Returnable Transport Packaging and their impact on the operations of a car parts manufacturer

Sammanfattning

Returnable Transport Packaging (RTP) are packaging which are reused repeatedly in a closed- loop supply chain. In the context studied, the RTP are shipped between two plants, in one direction filled with parts and empty in the other direction. This implies that the RTP are filled at one plant and emptied at another. Between the plants, the RTP are shipped on trains or trucks. The challenge studied in this master’s thesis is the temporarily stockouts of RTP leading to unplanned downtime at the production units. The studied company was Volvo Cars, with the branch Volvo Cars Body Components in particular. They produce steel components for several of Volvo Cars’s final assembly plants. In this study, the final assembly plants in Gothenburg and Ghent were included. However, the focus was on the operations at Volvo Cars Body Components in Olofström which is the plant responsible for the supply of RTP. Three research questions were used to fulfil the purpose of the master’s thesis which was to study the possibilities on how to mitigate the risk of unplanned downtime at the production units due to stockouts of returnable transport packaging (RTP). A simulation model was used to understand the closed-loop supply chain of RTP. In this simulation model, the flow of RTP can be seen as well as queues, inventory levels, loop times and service levels of RTP. The simulation model also enabled the possibility to experiment and create certain scenarios. For example, to see how a system with more available RTP would behave or to see how the system behaves with a higher demand of parts and RTP at the final assembly plants. The results of the simulation model together with the current state at Volvo Cars and a literature review showed that there is need for better management of the RTP. Both in how many RTP that are circulating in the system as well as how they are tracked and controlled. The number of RTP is affecting the service level of available RTP at Volvo Cars Body Components. If the number of RTP in the system is too low, there will on some occasions be no available RTP when needed. Therefore, a certain number of RTP is required to fulfil a certain service level. The tracking of RTP is currently insufficient as it has a track rate of less than 100 %. A 100 % reading and tracking rate must be ensured to be able to manage the RTP and the production better. It can be achieved by either automatic tracking or incentives for increasing the manual scanning rate. The 1:1 exchange method of RTP at the final assembly plants does not work in reality. Therefore, ordering RTP from the final assembly plants for each train departure should instead be done by Volvo Cars Body Components. Both to know in advance which RTP are expected to arrive and to better plan the downtime if the ordered RTP are not available. The proposed actions for Volvo Cars Body Components are to frequently update the number of RTP in the system and to ensure 100 % reading rate of the RTP to be able to plan the operations ahead.