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COQUALMO

Last Updated 6/29/2009

Model Rationale
Model Description
Papers, Reports, and Presentations
Model Status
Data Collection Program
Research Group
Research Sponsors
Cost Estimation Bibliography
For Further Information
The COCOMO Page
The COCOMO Suite
CSSE Home Page



Model Rationale

In software estimation, it is important to recognize the strong relationships between Costs,Schedule and Quality. They form three sides of the same triangle. Beyond a certain point (the "Quality is Free" point), it is difficult to increase quality without increasing either the cost or schedule or both for the software under development. Similarly, development schedule cannot be drastically compressed without degrading the quality of the software product and/or increasing the cost of development. Software estimation models can play an important role in facilitating the balancing of these three factors.

COQUALMO (COnstructive QUALity MOdel)--formerly called CODEFMO--is an estimation model that can be used for predicting number of residual defects/KSLOC (Thousands of Source Lines of Code) or defects/FP (Function Point) in a software product. It can be applied in the early activities such as analysis and design, as well as in the later stages for refining the estimate when more information is available. It enables 'what-if' analyses that demonstrate the impact of various defect removal techniques and the effects of personnel, project, product and platform characteristics on software quality. It also provides insights into determining ship time, assessment of payoffs for quality investments and understanding of interactions amongst quality strategies.


Model Description

The model depicted in Figure 1 shows that defects conceptually flow into a holding tank through various defect-source pipes and are drained off through various defect-elimination pipes. The defect source pipes are modeled as the "Software Defect Introduction Model" and the defect elimination pipes are being modeled as the "Software Defect Removal Model". For more details read usccse98-515.pdf.



 Click image to enlarge chart.


Papers, Reports, and Presentations

Journal Papers:

  • "Assessing Quality Processes with ODC COQUALMO"
  • Authors: Ray Madachy, Barry Boehm
  • Lecture Notes in Computer Science, Making Globally Distributed Software Development a Success Story, Volume 5007, 2008, Springer Belin / Heidelberg, pp. 198-209
  • PDF format
  • "An Early Look at COQUALMO in the JPL Environment"
  • Author: J.D. Powell
  • 17th International Forum on COCOMO and Software Cost Modeling, Los Angeles, CA, Sept. 2002
  • PDF format

Reports:

  • "ODC COQUALMO - A Software Defect Introduction and Removal Model using Orthogonal Defect Classification"
  • Authors: Ray Madachy, Barry Boehm
  • Technical Report USC-CSSE-2008-817
  • PDF format
  • "Bayesian Analysis of Software Costs and Quality Models"
  • Author: Sunita Chulani
  • PhD Dissertation (May 1999)
  • PDF format
  • "Modeling Software Defect Introduction Removal: COQUALMO (COnstructive QUALity MOdel)"
  • Authors: Sunita Chulani, Barry Boehm
  • Technical Report USC-CSE-99-510
  • PDF format
  • "Incorporating Bayesian Analysis to Improve the Accuracy of COCOMO II and Its Quality Model Extension"
  • Author: Sunita Chulani
  • PhD Qualification Report (Feb. 1998)
  • PDF format

Presentations:

  • 2007 International Forum on COCOMO and Software Cost Modeling 21 - "ODC COQUALMO"
  • Authors: Ray Madachy, Barry Boehm
  • PPT format
  • 2002 International Forum on COCOMO and Software Cost Modeling 17 - "COQUALMO Breakout Discussion Group"
  • Author: J.D. Powell
  • PDF format
  • 2002 International Forum on COCOMO and Software Cost Modeling 17 - "An Early Look at COQUALMO in the JPL Environment"
  • Author: J.D. Powell
  • PDF format
  • 2001 USC-CSE Annual Research Review - "COQUALMO and Orthogonal Defect Classification (ODC)"
  • Authors: Keun Lee, Sunita Chulani
  • PPT format
  • 1999 USC-CSE Annual Research Review - "Expert-Judgment Calibrated Quality Model Extension to COCOMO II: COQUALMO (COnstructive QUALity MOdel)"
  • Author: Sunita Chulani
  • PDF format
  • 1998 COCOMO and Software Cost Modeling International Forum 13 - "COQUALMO (COnstructive QUALity MOdel): Quality Model Extension to COCOMO II "
  • Author: Sunita Chulani
  • PDF format

Model Status

The model is expert-judgment based and the data collection activity has been started. We hope to get enough data points to validate and calibrate the model soon.

The version provided with the COCOMO book is available to download here. Please refer to Sunita Chulani's Dissertation.

The new ODC COQUALMO is available to affiliates only.


Data Collection Program

The key factor is continuing to improve the predictive accuracy of COQUALMO is good data. To that end, we are asking for the help of the software industry in collecting data. If you or the organization you work for has the ability to supply software development project data, we would like to hear from you. The benefit to you for participating in data collection will be the availability of a more accurate predictive model for estimating your software project costs. Additionally, you will have the opportunity to participate in the COQUALMO oriented workshops being planned at USC, and to receive calibrated versions of the implemented model before the general public.

For your convenience, we are providing below for download copies of the COCOMO II data collection instrument, and the standard data nondisclosure agreement USC-CSSE enters into with most of our data suppliers.

For further information or to discuss participation in the COQUALMO data collection program, please contact us.

Data Collection Documents:

  • COCOMO II/COQUALMO Cost Estimation Questionnaire
  • PDF format
  • USC-CSSE Data Nondisclosure Agreement
  • HTML format
  • PDF format



Research Group

  • Dr. Barry W. Boehm
  • A. Winsor Brown


Research Sponsors

Primary funding and technical support of the development of COQUALMO has been provided by the USC-CSSE Affiliates. We would like to take this opportunity to acknowledge their generous assistance, without whose help the development of COQUALMO would have been impossible.


Cost Estimation Bibliography

For an extensive bibliography of software cost estimation related papers and books go here.


For Further Information Please Contact:

Center for Software Engineering
Salvatori Hall Room 328
University of Southern California
941 W. 37th Place
Los Angeles, CA 90089-0781

Voice: (213) 740-5703
Fax: (213) 740-4927
Email:
awbrown@csse.usc.edu


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