The various embodiments of the present invention provide a PAS model for software design and development with a product layer including basic product level business objects (BO) to provide a basic functionality offered by software. An application layer is built on the product layer to include the application level business objects to provide inputs for a solution required by a user and to achieve desired business requirements. A solution layer is built on the application layer to include the solution level business object to address the specific business requirement of the user. The solution level business object is created using the application level business objects which is in turn created using the product level business objects to provide solution to meet the specific business requirement of the user.