is a term from the cleanroom technology. It describes a cleanroom concept in which all steps of a process are performed in a cleanroom with uniform classification. (In the concept of normal practice the cleanroom is divided into different areas with different classifications depending on the individual process requirements; the criterion is the number of particles of a defined size per unit volume). In the ballroom concept the cleanroom is equipped flexibly with devices and equipment depending on the process. Thereby, process equipment is sometimes encapsulated. This concept is increasingly becoming evident in single-use production facilities. See facility of the future.