Looking at the diagram above, you can see that not only are the multiple inputs that impact the maintenance, but there are several key outputs that provide the information necessary to plan a successful maintenance effort.



6. Conclusion



The conclusions of this article are:



• Software maintenance can be modeled using a simplistic method like Level of Effort Staffing, but this technique has significant drawbacks.



• Software maintenance costs can be significantly affected by management decisions during the developmental process.



• Software maintenance can be accurately estimated using parametric processes.



• Software maintenance is best modeled when development and management decisions are coupled with parametric cost estimation techniques.



REFERENCES



[1]Software Maintenance Concepts and Practices (second Edition) by Penny Grubb and Armstrong Takang, World Scientific, 2005.

[2]Estimating Software Intensive Systems; Richard Stuzke, 2005, Addison-Wesley.

[3]Lloyd Huff, George Novak; Lockheed Martin Aeronautics; Lockheed Martin Aeronautics Performance Based Software Sustainment for the F-35 Lightning II.

[4]G. Edward Bryan, "CP-6: Quality and Productivity Measures in the 15-Year Life Cycle of an Operating System," Software Quality Journal 2, 129-144, June 1993.

[5] Software Sizing, Estimation, and Risk Management; Daniel D. Galorath, Michael W. Evans, 2006, Auerbach Publications.