Payroll processing software (multi company)

The purpose of developing this software project is to fully automate salary system for multiple organizations. This software should be capable of calculating monthly salaries, Tax and Statutory report of employees. On the basis of certain formulas it will generate files as an output such as bank files and salary slips etc. The tax file is generated for the tax office. All the data such as, employee information, salaries, social security and tax will be stored in database as a track record. About Me:- Currently working for a private company, but want to start up with my own. I am not from business background but i am very much interested to start with. Initially i will be having no profit as i'm starting with service sector but surely will make profit in short term. I am looking for a healthy software to be built for very long run.