A PLC controlled semi-automatic rotary indexing system for assembly of foot valve is modelled and simulated using CATIA and Automation Studio. It is comprised of part feeders (Conveyors and vibratory bowl feeder), face plate, fixtures, components of foot valve (Body, cap, seal carrier, seal and cover) and electro-pneumatic system (Electro-pneumatic pick & place system and electro-pneumatic press) which are modelled using CATIA. The kinematic model of rotary indexing mechanism is successfully verified with ADAMS. The electro-pneumatic system that involves an electro-pneumatic circuit, PLC input/output cards and necessary HMI is designed and simulated using Automation Studio. The electro-pneumatic system works under the PLC ladder logic to assemble the parts of foot valve. The semi-automatic rotary indexing system is integrated and synchronized with PLC controlled electro-pneumatic system to complete the assembly of foot valve. A digital prototype is developed and verified through simulation for kinematics and process control using ADAMS and Automation Studio respectively.