Karner Use Case Point Estimation

Karner’s Use Case Point (UCP) Estimation is a method used to estimate the effort and time required for a software development project based on use cases. It is particularly useful for projects driven by object-oriented analysis and design.

Key Components of Karner’s UCP Estimation

1. Unadjusted Use Case Points (UUCP):

   • Use Case Weighting: Each use case is categorized as simple, average, or complex based on the number of transactions.
     • Simple: 1-3 transactions (Weight: 5)
     • Average: 4-7 transactions (Weight: 10)
     • Complex: More than 7 transactions (Weight: 15)
   • Actor Weighting: Each actor is also categorized by complexity:
     • Simple (Weight: 1)
     • Average (Weight: 2)
     • Complex (Weight: 3)

   UUCP = Total Use Case Points (from use cases) + Total Actor Points (from actors)

2. Technical Complexity Factors (TCF):

   • Consists of 13 factors that assess the project’s technical challenges (e.g., performance, security, concurrency). Each factor is assigned a value between 0 and 5, indicating the impact on the project.
   • TCF formula: $$TCF=0.6+(0.01\times \text{sum of technical factor ratings})$$

3. Environmental Complexity Factors (ECF):

   • Involves 8 factors that evaluate environmental and team factors (e.g., team experience, development tools, motivation). These factors are also rated between 0 and 5.
   • ECF formula: $$ECF=1.4+(-0.03\times \text{sum of environmental factor ratings})$$

4. Adjusted Use Case Points (AUCP):

   • After calculating the UUCP, it is adjusted using the TCF and ECF:

$$AUCP=UUCP\times TCF\times ECF$$

5. Effort Estimation:
   • To estimate the total effort, the AUCP is multiplied by the average effort per UCP (typically between 20 and 36 person-hours per use case point).

Key steps in UCP estimation:

1. Identify use cases and actors, and assign complexity weights.
2. Calculate the UUCP.
3. Evaluate the TCF and ECF and calculate the AUCP.
4. Multiply the AUCP by a standard value to estimate the total effort in person-hours.

This method provides a systematic approach to estimating project effort by considering both the use case model and the complexity of technical and environmental factors.

Example - Example Calculation - Karner Use Case Point Estimation