Use Case Points

What is this formula?

Use Case Points (UCP) estimate the functional size of a software project based on use cases, actors, technical factors, and environmental factors.

The method was introduced by Gustav Karner and is widely used during early project planning when detailed source code estimates are not yet available.

UCP is particularly useful for object-oriented software development projects.

When to use it

Use this formula when:

- estimating software projects from requirements,

- planning object-oriented systems,

- evaluating project scope,

- estimating effort before coding begins,

- comparing software development alternatives.

Example

Suppose a project has:

UUCP = 120

TCF = 0.95

ECF = 1.10

Formula:

UCP = UUCP × TCF × ECF

Substitution:

UCP = 120 × 0.95 × 1.10

UCP = 125.4

Result:

Use Case Points = 125.4

Applications

- Software estimation

- Agile project planning

- Requirements analysis

- Object-oriented development

- Cost estimation

- Resource planning

Note

Use Case Points is an empirical estimation model. The accuracy of the estimate depends heavily on the quality of use case definitions, actor classifications, and factor assessments. Different organizations may use slightly different weighting schemes and calibration factors based on historical project data.