Example Calculation - Karner Use Case Point Estimation

Example Calculation: Karner’s Use Case Point Estimation

Project Details

• Use cases: 3 use cases
  • Simple: 2 transactions (Weight = 5)
  • Average: 5 transactions (Weight = 10)
  • Complex: 9 transactions (Weight = 15)
• Actors: 3 actors
  • Simple (Weight = 1)
  • Average (Weight = 2)
  • Complex (Weight = 3)

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Step 1: Calculate Unadjusted Use Case Points (UUCP)

Use Case Weighting

• Simple: 1 use case × 5 = 5 points
• Average: 1 use case × 10 = 10 points
• Complex: 1 use case × 15 = 15 points

Total Use Case Points: $5+10+15=30$ points

Actor Weighting

• Simple: 1 actor × 1 = 1 point
• Average: 1 actor × 2 = 2 points
• Complex: 1 actor × 3 = 3 points

Total Actor Points: $1+2+3=6$ points

Total Unadjusted Use Case Points (UUCP)

$$UUCP=30+6=36\text{ points}$$

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Step 2: Calculate Technical Complexity Factors (TCF)

13 Technical Factors

For simplicity, assume the ratings for the 13 technical factors sum to 25.

$$TCF=0.6+(0.01\times 25)=0.6+0.25=0.85$$

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Step 3: Calculate Environmental Complexity Factors (ECF)

8 Environmental Factors

Assume the ratings for the 8 environmental factors sum to 12.

$$ECF=1.4+(-0.03\times 12)=1.4-0.36=1.04$$

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Step 4: Calculate Adjusted Use Case Points (AUCP)

$$AUCP=UUCP\times TCF\times ECF$$ $$AUCP=36\times 0.85\times 1.04=31.824\approx 31.8\text{ points}$$

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Step 5: Estimate Effort

Assuming 20 person-hours per UCP, the total effort estimate is:

$$31.8\times 20=636\text{ person-hours}$$

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Summary of Effort Estimation

• Unadjusted Use Case Points (UUCP): 36 points
• Adjusted Use Case Points (AUCP): 31.8 points
• Effort estimate: 636 person-hours

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This example demonstrates how Karner’s Use Case Point Estimation can be used to estimate effort for a software project based on use cases, technical complexity, and environmental factors.