Material Flow Improvement Through Sequence Delivery : A study on material delivery in the automotive components industry

Sammanfattning

The purpose of this thesis was to understand how a system for delivering parts can be improved through sequence delivery to one assembly activity and to evaluate the potential impact on logistics performance indicators. The study was conducted within a high-variant engine assembly environment where challenges related to line-side inventory, material flow, and space utilization were identified. A qualitative case study approach was used, combining semi-structured interviews and observations. The empirical findings were analysed using concepts related to lean manufacturing, Just in Sequence, kitting, scheduling, and the engineering design process. The findings identified three main problem areas within the current material feeding system: scheduling, planning, and reverse logistics. Scheduling issues were related to high line-side inventory levels caused by fixed replenishment logic and limited responsiveness in material delivery. Planning issues were linked to the accumulation of partially used pallets during variant transitions, resulting in unnecessary work-in-progress inventory. Reverse logistics issues were connected to variant-specific containers, creating congestion and inefficient handling of empty containers. Based on these findings, a conceptual sequence delivery design was developed consisting of three integrated elements: a supermarket system, transition kitting, and standardized return containers. The proposed design aims to reduce line-side inventory, improve space utilization, and increase synchronization between production and material delivery. The study contributes practically by presenting a conceptual design for sequence delivery within a real industrial assembly environment. Theoretically, the study demonstrates how the engineering design process can be applied to logistics and process design rather than traditional product development.