A system and method for the modeling of biopharmaceutical batch process manufacturing facilities uses process time lines. The system employs an eleven-field delimited string code which specifies the unit identifier code and the iteration value for each of the ten levels of nested scheduling cycles of the biopharmaceutical drug production process being modeled. The method includes generating a process time line using operational parameters, a block flow diagram, and a set of scheduling cycles for each of a sequence of unit operations. The process time line is used as a tool for batch processing and facility design.