Accession Number : ADA301377

Title :   Calibration of the Price S Software Cost Model.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Galonsky, James C.

PDF Url : ADA301377

Report Date : SEP 1995

Pagination or Media Count : 92

Abstract : As more Department of Defense resources are being allocated toward software development, the necessity to accurately plan for software costs has become critical. Obtaining reliable estimates from software cost models, like PRICE S, can be a problem when input parameters are not precisely defined or calibrated. This research effort centered on refining Productivity Factor (PROFAC) values for defense industry applications. The Space and Missile Systems Center Database was used to calibrate PROFAC values for eleven stratified data sets: military ground, military mobile, missile, unmanned space, Ada, Assembly, C, COBOL, FORTRAN, JOVIAL, and PASCAL. The accuracy of the calibrations was determined through comparisons of calibrated and default generated estimates versus actuals. Statistical methods used to make the comparisons included standard deviation, mean absolute error, mean relative error, and percentage of records estimated within twenty-five percent of actuals. The results were surprising in that, in most instances, the calibrated PROFAC values estimated actual cost well, but not overwhelmingly better than the default PROFAC values. The main contributing factor to this phenomena was variability within the stratified data sets. The results were encouraging, however, in that the results from seven of the eleven stratified data sets suggested either a new refinement in PROFAC values based upon the calibration or the recommendation to use PROFAC values from analogous calibrated records for estimating future efforts.

Descriptors :   *COMPUTER PROGRAMS, *COST MODELS, *CALIBRATION, DATA BASES, INPUT, DEPARTMENT OF DEFENSE, PARAMETERS, ACCURACY, ESTIMATES, COSTS, FORTRAN, RELIABILITY, ERRORS, PRODUCTIVITY, MEAN, RECORDS, STATISTICAL PROCESSES, DEFENSE INDUSTRY, STRATIFICATION, STANDARD DEVIATION, HIGH LEVEL LANGUAGES, UNMANNED SPACECRAFT.

Subject Categories : Economics and Cost Analysis
      Computer Programming and Software

Distribution Statement : APPROVED FOR PUBLIC RELEASE