Function Point Analysis in Software Engineering - Mini Project: Build & Apply

Function Point Analysis

📖 Scenario: You are a software analyst working on a new project. You need to estimate the size of the software using Function Point Analysis (FPA). This method helps you understand the complexity and effort required by counting different types of functions in the system.

🎯 Goal: Build a simple Function Point Analysis model by listing function types, assigning complexity weights, calculating unadjusted function points, and applying a value adjustment factor to get the final function point count.

📋 What You'll Learn

Create a dictionary with function types and their counts

Create a dictionary with complexity weights for each function type

Calculate the unadjusted function points by multiplying counts by weights and summing

Apply a value adjustment factor to calculate the final function points

💡 Why This Matters

🌍 Real World

Function Point Analysis helps project managers estimate software size and effort before development starts, improving planning and budgeting.

💼 Career

Software analysts, project managers, and developers use function points to communicate project scope and complexity clearly.

1

DATA SETUP: Define function counts

Create a dictionary called function_counts with these exact entries: 'External Inputs': 10, 'External Outputs': 7, 'Internal Logical Files': 5, 'External Interface Files': 3, and 'External Inquiries': 4.

Software Engineering

# Create the function_counts dictionary with exact entries
# Your code here

Hint

Use a Python dictionary with the exact keys and values given.

2

CONFIGURATION: Define complexity weights

Create a dictionary called complexity_weights with these exact entries: 'External Inputs': 4, 'External Outputs': 5, 'Internal Logical Files': 10, 'External Interface Files': 7, and 'External Inquiries': 3.

Software Engineering

function_counts = {
    'External Inputs': 10,
    'External Outputs': 7,
    'Internal Logical Files': 5,
    'External Interface Files': 3,
    'External Inquiries': 4
}
# Create the complexity_weights dictionary with exact entries
# Your code here

Hint

Use a dictionary with the exact keys and weights given.

3

CORE LOGIC: Calculate unadjusted function points

Create a variable called unadjusted_fp and set it to the sum of the products of counts and weights for each function type using a for loop over function_counts.items().

Software Engineering

function_counts = {
    'External Inputs': 10,
    'External Outputs': 7,
    'Internal Logical Files': 5,
    'External Interface Files': 3,
    'External Inquiries': 4
}

complexity_weights = {
    'External Inputs': 4,
    'External Outputs': 5,
    'Internal Logical Files': 10,
    'External Interface Files': 7,
    'External Inquiries': 3
}

# Calculate unadjusted_fp by summing count * weight for each function type
# Your code here

Hint

Use a for loop to multiply each count by its weight and add to unadjusted_fp.

4

COMPLETION: Apply value adjustment factor

Create a variable called value_adjustment_factor and set it to 1.1. Then create a variable called final_function_points and set it to unadjusted_fp multiplied by value_adjustment_factor.

Software Engineering

function_counts = {
    'External Inputs': 10,
    'External Outputs': 7,
    'Internal Logical Files': 5,
    'External Interface Files': 3,
    'External Inquiries': 4
}

complexity_weights = {
    'External Inputs': 4,
    'External Outputs': 5,
    'Internal Logical Files': 10,
    'External Interface Files': 7,
    'External Inquiries': 3
}

unadjusted_fp = 0
for function_type, count in function_counts.items():
    unadjusted_fp += count * complexity_weights[function_type]

# Set value_adjustment_factor to 1.1 and calculate final_function_points
# Your code here

Hint

Multiply unadjusted_fp by value_adjustment_factor to get final_function_points.

Practice

1. What is the main purpose of Function Point Analysis in software engineering?

easy

A. To design the user interface

B. To write the actual code for software

C. To measure the size of software based on its features

D. To test software for bugs

Solution

1. Step 1: Understand the goal of Function Point Analysis

   Function Point Analysis is used to measure software size by counting its features, not for coding or testing.

2. Step 2: Match the purpose with the options

   Among the options, only measuring software size by features matches the purpose.

3. Final Answer:

   To measure the size of software based on its features -> Option C

4. Quick Check:

   Function Point Analysis = software size measurement [OK]

Hint: Focus on measuring software features, not coding or testing [OK]

Common Mistakes:

• Confusing Function Point Analysis with coding or testing
• Thinking it designs UI
• Assuming it measures time instead of size

2. Which of the following is a correct step in the Function Point Analysis process?

easy

A. Counting the number of functions in the software

B. Writing test cases for each function

C. Compiling the source code

D. Deploying the software to users

Solution

1. Step 1: Identify the steps in Function Point Analysis

   The process involves counting functions, weighting them, and adjusting for complexity.

2. Step 2: Compare options with the process steps

   Only counting the number of functions matches the process; other options relate to later stages.

3. Final Answer:

   Counting the number of functions in the software -> Option A

4. Quick Check:

   Function Point Analysis step = counting functions [OK]

Hint: Remember: counting functions is the first step [OK]

Common Mistakes:

• Mixing analysis steps with coding or deployment
• Thinking testing is part of Function Point Analysis
• Confusing compilation with analysis

3. If a software project has 10 input functions, 5 output functions, and 3 inquiry functions, and each input counts as 4 points, output as 5 points, and inquiry as 3 points, what is the total unadjusted function point count?

medium

A. 85

B. 80

C. 90

D. 74

Solution

1. Step 1: Calculate points for each function type

   Input: 10 x 4 = 40 points; Output: 5 x 5 = 25 points; Inquiry: 3 x 3 = 9 points.

2. Step 2: Sum all points to get total function points

   Total = 40 + 25 + 9 = 74 points.

3. Step 3: Verify if any other function types are included

   No other types given, so total unadjusted function points = 74.

4. Final Answer:

   74 -> Option D

5. Quick Check:

   Sum of weighted functions = 74 [OK]

Hint: Multiply counts by weights, then add all [OK]

Common Mistakes:

• Adding counts without weights
• Multiplying weights incorrectly
• Forgetting to sum all function types

4. A software project's function point count was calculated as 120, but the complexity adjustment factor was mistakenly applied as 0.8 instead of 1.2. What is the corrected adjusted function point count?

medium

A. 96

B. 144

C. 120

D. 100

Solution

1. Step 1: Understand the adjustment factor application

   Adjusted function points = Unadjusted count x Complexity factor.

2. Step 2: Calculate corrected adjusted function points

   Corrected = 120 x 1.2 = 144.

3. Final Answer:

   144 -> Option B

4. Quick Check:

   120 x 1.2 = 144 [OK]

Hint: Multiply by correct factor, not the wrong one [OK]

Common Mistakes:

• Using the wrong adjustment factor
• Confusing multiplication with division
• Ignoring adjustment factor altogether

5. A project has the following function counts: 8 inputs, 6 outputs, 4 inquiries, 5 internal logical files, and 3 external interface files. The weights are: inputs=4, outputs=5, inquiries=3, internal files=7, external files=5. The complexity adjustment factor is 1.1. What is the final adjusted function point count?

hard

A. 136.4

B. 176

C. 165

D. 190

Solution

1. Step 1: Calculate unadjusted function points

   Inputs: 8x4=32; Outputs: 6x5=30; Inquiries: 4x3=12; Internal files: 5x7=35; External files: 3x5=15. Sum = 32+30+12+35+15=124.

2. Step 2: Apply complexity adjustment factor

   Adjusted = 124 x 1.1 = 136.4.

3. Final Answer:

   136.4 -> Option A

4. Quick Check:

   124 x 1.1 = 136.4 [OK]

Hint: Multiply counts by weights, sum, then multiply by factor [OK]

Common Mistakes:

• Forgetting to multiply by adjustment factor
• Adding weights instead of multiplying
• Misreading counts or weights