1.It is a very long and detailed document.Therefore it needs to be amended quite regularly to keep it updated.
2.Indian constitution felt that it has to be in accordance with people's aspirations and changes in the society.The constitution describes the institutional arrangements in a very legal language.The basic institutional design is not very difficult to undrestand.
3.The Indian constitution lays down a procedure for choosing persons to govern the country.It defines who will have how much power to take which decisions.