Abstract: Genetic programming is an automatic programming technique that is used to evolve computer programs by applying genetic algorithm. There are a number of representation methods to illustrate these programs, such as LISP expressions. This study investigates the effectiveness of genetic programming in solving the symbolic regression problem by using different representation scheme, in which, the population programs are expressed as integer sequences rather than lisp expressions. This approach is called Genetic Algorithm for Developing Software (GADS). Furthermore, this study introduces the concept of reusability to GADS and explains how to evolve reusable programs using GADS. Different architecture altering operations are applied such as function deletion and arguments duplication.