AGVs and AMRs in materials handling: integration challenges in the design of the loading/unloading points

In modern manufacturing environments, the integration of production and logistics systems is increasingly critical but remains insufficiently explored, particularly at the operational interface where material handling crosses with machine servicing. Existing literature has mostly focussed on Automated Guided Vehicles (AGVs) and Autonomous Mobile Robots (AMRs) from a routing, scheduling, or performance optimisation point of view, without addressing how different levels of automation at the production-machine interface affect overall system cost. This study tries to fill this gap by analyzing the integration challenges, specifically the decision between manual, semi-automated, and fully automated loading and unloading strategies. A novel mathematical cost model is proposed, together with numerical simulations, and validated through a case study in an injection molding company. The model quantifies and compares scenarios in terms of total annual cost per machine, incorporating investment, operational, maintenance, and quality-related costs. Results show that semi-automated solutions combined with AMRs can offer significant cost advantages in medium-productivity settings, while full automation becomes economically viable only at high throughput levels. These insights provide guidelines for industries to customise automation strategies based on operational parameters and open new paths for future research on adaptive, cost-optimised production-logistics integration.