CoCoMo Cost Model

You can use this to obtain gross estimates of effort required for software development and maintenance efforts. The model is initialized with information to help you estimate total year 2000 compliance costs. Some management savvy with respect to retiring obsolete systems and making other necessary changes can reduce this cost.

Notes on CoCoMo Model

The default values are for an actual $1.8 billion company.


  • Programs. The total number of application programs in your portfolio.

  • Average # Lines per Program. The mean Source Lines of Code (SLOC) in each program.

    While there is some debate as to what counts as source, the COCOMO model can be calibrated for your counting method. For the purposes of a gross upper limit, count all source including comments – you have to maintain those comments, they count as a cost.

  • Source Lines of Code (SLOC). Computed from programs and lines per program. This applet can compute any one of programs, average lines and SLOC from the other two.

  • Adaptation Factor. The fraction of new development. This is the sum of new design, new implementation and new testing which must be done. For year 2000 compliance, the 4% factor seems typical.

  • Labor per Hour. The weighted average labor rate which you expect to pay. This should be your total cost, either in contractor fees or fully burdened salaries. This should include all skill levels and their relative contribution. Our example rate assumes teams of five people with a total cost of $35 per hour ($70K per year) plus a team leader at $65 her hour ($130K per year).

  • Cost Drivers. These permit fine-tuning the estimate based on a number of cost drivers. For more information, see the COCOMO or COCOMO2 documentation.

  • Person-Months Effort. The total effort given the source lines of code.

  • Total Cost. The months of effort times a standard utilization rate of 156 hours per month times the labor rate per hour.

  • Months Duration. T he expected duration of the given effort. This allows computing the number of staff required. Note that very little can be done to compress the duration. Reduction in the effort (by reducing the number of programs to be brought into compliance) us the only effective solution.

COCOMO products from Softstar Systems

Some COCOMO Notes

COCOMO 2.0 Project


Applet Source