AGV-baserad internlogistik i praktiken : En fallstudie av ineffektiviteter, orsaker och förbättringsåtgärder

Sammanfattning

This thesis examines inefficiencies in AGV-based internal material flows in a manufacturingenvironment. The study was conducted at a Swedish manufacturing company where anexisting Automated Guided Vehicle system is used for internal material transportation. Thepurpose is to analyze the material flow connected to the AGV system, identify inefficienciessuch as disturbances, downtime and waiting times, and provide an analytical basis forpossible improvement measures. The study addresses three research questions: what inefficiencies occur in AGV-basedinternal material handling, what factors contribute to these inefficiencies, and whatimprovement measures can be identified in relation to feasibility. The study was conducted as a combined qualitative and quantitative case study with anabductive approach. Data was collected through interviews, observations, and AGV operatingdata. The material from the interviews was analyzed thematically and the quantitative datawas analyzed descriptively in order to identify patterns related to transport times, error codes,blockages and system status. The results indicate that several inefficiencies occur in the AGV-based material flow. Theseinclude waiting times, queue formation, blockages, error stops, variation in transport times,manual interventions and insufficiently standardized routines. During the studied period, theAGV system completed 51,894 transports with an average transport time of 27 minutes. Theoperating data also showed recurring error statuses, blockage time and variation in transportduration. The analysis indicates that the identified inefficiencies are related to a combination oftechnical, structural and organizational factors. The AGV system is based on inductiveguidewire navigation, which limits route flexibility and makes the system dependent onpredefined paths. Layout-related factors also affect the material flow, particularly in areaswhere several flows meet, such as crossings, charging areas, service points and pick-up anddrop-off locations. Organizational factors, such as unclear responsibilities, reactive faulthandling and limited standardization of routines, also influence how disturbances arehandled. The study concludes that AGV-based material flows should be analyzed as sociotechnicalsystems, where technology, layout, routines and human actions interact. The results suggestthat improvement measures may be implemented gradually. In the short term, standardizedroutines, clearer responsibility, battery handling, sensor cleaning, route inspection and faultresponse are relevant areas for improvement. In the longer term, layout changes, technicalupgrades or hybrid solutions combining AGV and AMR technology may be considered. Theoverall conclusion is that improvement efforts should focus on increasing the stability,robustness and efficiency of the internal material flow.