This unit of competency defines the skills and knowledge required to design an engineering application using a programmable logic controller (PLC). It includes consideration of sustainability implications, work health and safety (WHS) and automation safety.The client may be internal or external to the designer’s organisation.The unit applies to the control of machines, equipment or processes that can have thermodynamic, hydrodynamic, fluid power or mechanical system elements using a PLC. Control functions can be digital and analog and can also include feedback. Network and remote control can also be used. The unit is suitable for mechatronics and automated systems designers, systems maintenance, machine and process control, or computer-integrated manufacturing (CIM) designers. Design activities can also include reverse engineering and design rectification or modifications of an existing design.Individuals completing this work either already have or are developing skills and experience in the evaluation of PLC systems, application of computing, controllers, mathematics, and basic electrical and electronics safety procedures. Additionally, experience in mechanical, fluid power, thermodynamic, manufacturing methods and processes may be required by particular system designs.No licensing, legislative or certification requirements apply to this unit at the time of publication.