Use case points (UCP)
Is a software estimation technique used the measure the software size with Use cases Developed in 1993 for sizing and estimating projects using OO methodology The concept of UCP is similar to FP
Use cases describe the functionality of the system Use cases model the dialog between the actors and the system Primary purpose is to document functional requirements but also used for testing purposes
Compute unadjusted use case weight (UUCW)
Compute unadjusted actor weight (UAW)
Compute technical complexity factor (TCF)
Compute environmental complexity factor (ECF)
Compute the final size estimate
Compute UUCW
Count the number of simple, average, complex use cases based on the number of transactions as per table below.
| Use case classification | Type of actor | Weight |
|---|---|---|
Simple | 1 to 3 transactions | 5 |
Average | 4 to 7 | 10 |
Complex | 8 or more | 15 |
UUCW = N_s 5 + N_a 10 + N_c * 15
Compute UAW
Count the number of simple, average, complex actors
| Actor classification | Type of Actor | Weight |
|---|---|---|
Simple | External system interacting using a well defined API | 1 |
Average | External system using a standard protocol | 2 |
Complex | Human actor using GUI | 3 |
UAW = N_s 1 + N_a 2 + N_c * 3
Compute TCF
Compute ECF
Compute final UCP
UCP = (UUCW + UAW) TCF ECF
Advantages of UCP
UCP are based on use cases and can be measured very early in the project life cycle
UCP based estimates are found to be close to actuals when estimation is performed by experienced people
UCPs are easy to use and do not call for additional analysis
Use cases are being used vastly as a method of choice to describe requirements
Disadvantages of UCP
UCP can be used only when requirements are written in the form of use cases
Dependant on goal oriented, well written use cases
Technical and environmental factors have high impact on UCP
Not as well established as FPs
Last updated
