How is batch process control different from continuous process control?

Batch control involves discrete, time-based operations with defined start and end points, following recipes and sequences through phases (charging, heating, reacting, discharging). ISA-88 standard defines equipment hierarchy (unit, equipment module, control module) and recipe structure. Batch requires: sequential function charts for phase logic, flexible setpoint profiles, transition conditions between phases, and recipe management. Unlike continuous control with steady-state operation, batch involves frequent startup/shutdown and product changeovers requiring different tuning and control strategies.