Hello Dhiman Kakati,
You are welcome anytime… Even though you may not be having any difficulty and as you mentioned MS Word may suffice your needs as of now but you may need MS Visio at some point becuase it has a higher degree of versitality and you can almost create any sort of a design you like.. Infact literally you can draw anything in visio… So do look for a licensed version if possible… All the best
regards
sahil singh