Early size prediction for C and Pascal programs

Cost estimation is an important aspect of the management of software development projects. Most cost estimation models require an estimate of the size of the program to be developed. Accurate size estimation is thus critically important. This research relates the size of C and PASCAL programs to information available at successive stages in program development. The data considered are counts of subprograms and variables. Simple models using only these data are shown to be not accurate enough after specification and high-level design. After detailed design, though, they give acceptable estimates for both languages, even across a range of sizes and applications. Estimates based on a weighted variable count (where each variable is weighted by the number of subprograms in which it is referenced) are better than those based on simple variable counts.