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Sample Planning Scenarios
| Project | Model | Mode | Size | EAF | Effort | Schedule | Avg Staff |
|---|---|---|---|---|---|---|---|
| Inventory API Suite | Intermediate | Organic | 12 KLOC | 0.96 | 41.50 PM | 10.30 months | 4.03 |
| HR Workflow Portal | Intermediate | Semi-Detached | 24 KLOC | 1.08 | 114.00 PM | 13.10 months | 8.70 |
| Industrial Control Console | Intermediate | Embedded | 18 KLOC | 1.15 | 102.70 PM | 10.90 months | 9.42 |
These values are illustrative examples for benchmarking. Real projects should be recalculated using your actual size, rates, cost drivers, contingency, and schedule assumptions.
COCOMO Effort and Schedule Formula
This tool supports Basic and Intermediate COCOMO. Basic COCOMO estimates effort from project size and development mode. Intermediate COCOMO adds an effort adjustment factor from selected cost drivers.
Effort (Basic) = a × (KLOC)^b
Effort (Intermediate) = a × (KLOC)^b × EAF
Adjusted Effort = Base Effort × (1 + Contingency ÷ 100)
Schedule = c × (Base Effort)^d
Adjusted Schedule = Base Schedule × (1 + Schedule Buffer ÷ 100)
Average Staffing = Adjusted Effort ÷ Adjusted Schedule
Total Hours = Adjusted Effort × Hours per Person-Month
Adjusted Cost = Adjusted Effort × Labor Rate
Productivity = LOC ÷ Adjusted Effort
Mode coefficients used:
- Basic Organic: a = 2.4, b = 1.05, c = 2.5, d = 0.38
- Basic Semi-Detached: a = 3.0, b = 1.12, c = 2.5, d = 0.35
- Basic Embedded: a = 3.6, b = 1.20, c = 2.5, d = 0.32
- Intermediate Organic: a = 3.2, b = 1.05, c = 2.5, d = 0.38
- Intermediate Semi-Detached: a = 3.0, b = 1.12, c = 2.5, d = 0.35
- Intermediate Embedded: a = 2.8, b = 1.20, c = 2.5, d = 0.32
How to Use This Calculator
- Enter a project name for reporting clarity.
- Select Basic or Intermediate COCOMO.
- Choose the development mode that best matches your project.
- Enter estimated software size in KLOC.
- Add labor rate and hours per person-month.
- Set contingency and schedule buffer to reflect risk tolerance.
- Pick cost driver ratings if you are using Intermediate COCOMO.
- Press Estimate Effort to show results above the form.
- Review effort, schedule, staffing, cost, tables, and graphs.
- Use CSV or PDF export for documentation and stakeholder sharing.
Frequently Asked Questions
1. What does COCOMO estimate?
COCOMO estimates software development effort, delivery time, staffing, and cost using project size and project environment assumptions. It helps planners compare scenarios before budgeting or assigning teams.
2. When should I use Basic instead of Intermediate COCOMO?
Use Basic COCOMO when you only have rough size and mode information. Use Intermediate COCOMO when you can rate reliability, complexity, team capability, tools, and schedule pressure.
3. What is KLOC?
KLOC means thousands of delivered source lines of code. A project sized at 25 KLOC represents about 25,000 delivered lines, excluding non-deliverable support artifacts.
4. What is the effort adjustment factor?
The effort adjustment factor, or EAF, is the product of selected cost driver multipliers. Values above 1.00 increase effort, while values below 1.00 reduce effort.
5. Why add contingency and schedule buffer?
Contingency covers uncertain effort beyond the model output. Schedule buffer adds calendar protection for reviews, rework, staffing changes, dependencies, approvals, and delivery risk.
6. Are the phase allocations fixed?
No. The tool provides a practical phase split for planning visibility. Teams may adjust phase percentages to reflect lifecycle style, compliance demands, architecture intensity, and testing scope.
7. Can I use this for agile projects?
Yes, as an early estimation baseline. You can use COCOMO for release-level planning, then refine staffing, sprint capacity, backlog scope, and burn forecasts with actual delivery data.
8. Why is productivity shown in LOC per person-month?
That metric provides a quick benchmark between scenarios. It helps identify whether a project assumption appears overly optimistic, overly padded, or simply inconsistent with prior delivery history.