What are the draw backs of DCS over PLC?

PLC have a faster logic scan (~10ms) is required to perform motor or motion control. In contrary, DCS control loops requires deterministic scan execution at a speed of 100 to 500 ms. 

If the system to designed required less no of I/Os, PLC is a better choice in terms of the lifecycle cost.

DCs combines one or more PKCs to and allows the integrator to build both together.

Corel Draw we Used As to the any design and Make a all Drawing Program 

PLC's are better with discrete control (on/off) and DCS's tend to be better with Analog control

combo can do a lot of the same things a DCS does. The best approach is to list what your process needs, and see if you need enough features to justify a DCS.

scan time more than plc , in ESD system we need less scan time .

Corel Draw is one of the easiest and quickest drawing programs and text editors

DCS HAS REDUNDANCY BUT PLC HAS NOT