The required Contamination Control Strategy (CCS) for aseptic processes according to Annex 1 triggers similar strategies for low bioburden biologic drug substances produced according to Annex 2. Maximum contamination prevention is achieved by designing solutions with built-in monitoring. Such solutions are called “functionally closed”. The presentation provides hands-on examples on possible improvements on the process equipment allowing on the other side to reduce cleanroom classes. Special focus is on hybrid production facilities with stainless steel and single-use equipment.