Accession Number : ADA319050

Title :   Calibration of the Softcost-R Software Cost Model To the Space and Missile Systems Center (SMC) Software Database (SWDB).

Descriptive Note : Master's thesis,

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

Personal Author(s) : Southwell, Steven V.

PDF Url : ADA319050

Report Date : SEP 1996

Pagination or Media Count : 100

Abstract : The rising number and importance of Department of Defense software developments, when combined with declining defense budgets, has resulted in a critical need to accurately plan and manage software development costs and schedules. Unfortunately, the increasing size, complexity, and diversity of these software developments has made accurate estimating problematic. Uncalibrated software cost models have not generally produced reliable results due to generic default parameters and improper usage. The default parameters cannot hope to accurately represent and predict the wide variability of software efforts to which the models are being applied. However, some of the models have achieved improved accuracy by calibration from their generic default parameters to new parameter values based on specific characteristics of the development efforts being estimated. This research effort focused on the calibration of SoftCost-R, Version 8.4, to specific stratified data sets obtained from the Space and Missile Systems Center (SMC) Software Database, Version 2.1, (SWDB). The accuracy of the new calibrated inputs was verified through comparisons between the calibrated and default estimates and the actual cost data. Statistical methods used to make the comparisons included magnitude of relative error (MRE), mean magnitude of relative error (MMRE), root mean square (RMS), relative root mean square (RRMS), and prediction level Pred (k/n) or percentage of estimates within (100 * k/n)% of the actual costs. The new calibrated parameters resulted in more accurate effort estimates and the calibration method appeared to be valid. However, the accuracy improvement was neither complete nor all encompassing.

Descriptors :   *COMPUTER PROGRAMS, *DATA BASES, *COST MODELS, *CALIBRATION, DEPARTMENT OF DEFENSE, PREDICTIONS, PARAMETERS, ACCURACY, THESES, VARIATIONS, COSTS, RELIABILITY, ERRORS, MEAN, STATISTICAL PROCESSES, STRATIFICATION, MILITARY BUDGETS.

Subject Categories : Economics and Cost Analysis
      Computer Programming and Software
      Computer Systems

Distribution Statement : APPROVED FOR PUBLIC RELEASE