If I am a specified professional, I can go the presumptive way, provided I declare my income to be at least 50% of my gross receipts or revenues.
This way I need not maintain books, all my expenses and depreciation are presumed considered, and completes my tax records compliances.
This option is only to enable the small businessmen and professionals to declare and pay a flat % of their receipts as income, and do away with the complexities of detailed records and books.