1. A method for effort estimation of a package based software project, comprising the steps of: identifying one or more components from a configuration table to implement at least one of a use case flow or a non functional requirement (NFR) or an interface document or combinations thereof derived using an use case of the software project; sequencing the identified one or more components to prioritize execution of the use case of the software project; and attributing complexity of the identified one or more components to determine the effort estimation for execution of the use case by mapping the identified one or more components to a predefined unit effort guidelines table, wherein the attributing complexity includes using an unit effort table for determining the effort estimation requirement for execution of each component of the use case.