The book presents the proceedings of the 6th EAI International Conference on Management of Manufacturing Systems (MMS 2021), which took place online on October 6, 2021. The conference covered management of manufacturing systems with support for Industry 4.0, logistics and intelligent manufacturing systems and applications, cooperation management and its effective applications. Topics include RFID applications, economic impacts in logistics, ICT support for Industry 4.0, industrial and smart logistics, intelligent manufacturing systems and applications, and much more.