Requirements validation and verification in Software Engineering - Step-by-Step Execution

Concept Flow - Requirements validation and verification

Start: Requirements Document

↓

Verification: Are requirements correct and complete?

↓

Validation: Do requirements meet user needs?

↓

Re-verify

↓

Approved

↓

End

The process starts with checking requirements for correctness (verification), then checks if they meet user needs (validation). If issues are found, requirements are fixed and rechecked until approved.

Execution Sample

Software Engineering

1. Review requirements for completeness and correctness.
2. Check if requirements fulfill user needs.
3. If errors, revise requirements.
4. Repeat verification and validation until approved.

This process ensures requirements are both correct and useful before development.

Analysis Table

Step	Action	Check/Question	Result	Next Step
1	Verify requirements	Are requirements correct and complete?	No	Fix requirements
2	Fix requirements	Revise requirements document	Updated	Re-verify
3	Verify requirements again	Are requirements correct and complete?	Yes	Validate requirements
4	Validate requirements	Do requirements meet user needs?	No	Revise requirements
5	Revise requirements	Update requirements based on feedback	Updated	Re-verify
6	Verify requirements	Are requirements correct and complete?	Yes	Validate requirements
7	Validate requirements	Do requirements meet user needs?	Yes	Approve requirements
8	Approve requirements	Requirements are ready for development	Approved	End process

💡 Requirements are approved after passing verification and validation checks.

State Tracker

Variable	Start	After Step 2	After Step 5	Final
Requirements Document	Initial draft	Revised draft	Revised draft	Approved document
Verification Status	Not checked	Failed	Failed	Passed
Validation Status	Not checked	Not checked	Failed	Passed

Key Insights - 3 Insights

Why do we need to verify requirements before validating them?

Verification ensures requirements are correct and complete (see steps 1 and 3 in execution_table). Without this, validation might test wrong or incomplete requirements.

What happens if requirements fail validation?

If validation fails (steps 4 and 7), requirements must be revised and re-verified (steps 5 and 6) before approval, ensuring they meet user needs.

Can requirements be approved without validation?

No, approval only happens after both verification and validation pass (step 8). This ensures requirements are both correct and useful.

Visual Quiz - 3 Questions

Look at the execution_table, at which step do requirements first pass verification?

A Step 6

B Step 1

C Step 3

D Step 8

💡 Hint

Check the 'Result' column in step 3 of execution_table.

According to variable_tracker, what is the status of validation after step 5?

A Failed

B Not checked

C Passed

D Approved

💡 Hint

Look at 'Validation Status' after step 5 in variable_tracker.

If requirements fail verification at step 1, what is the next immediate action?

A Approve requirements

B Fix requirements

C Validate requirements

D End process

💡 Hint

See the 'Next Step' column for step 1 in execution_table.

Concept Snapshot

Requirements Verification and Validation:
- Verification checks if requirements are correct and complete.
- Validation checks if requirements meet user needs.
- Fix and revise requirements if checks fail.
- Repeat until requirements pass both checks.
- Only then approve for development.

Full Transcript

Requirements validation and verification is a two-step process to ensure software requirements are both correct and useful. First, verification checks if the requirements are complete and accurate. If they fail, they are revised and rechecked. Next, validation ensures the requirements meet the actual needs of users. If validation fails, requirements are revised again and re-verified. This cycle repeats until requirements pass both verification and validation, after which they are approved for development. This process prevents errors and misunderstandings early in the project.

Practice

1. What is the main question that requirements validation tries to answer?

easy

A. Is the code free of bugs?

B. Are we building the right product?

C. Are we building the product right?

D. Is the software delivered on time?

Solution

1. Step 1: Understand the definition of validation

   Validation checks if the product meets the user's real needs and expectations.

2. Step 2: Match the question to validation

   Validation asks if we are building the right product, ensuring it solves the correct problem.

3. Final Answer:

   Are we building the right product? -> Option B

4. Quick Check:

   Validation = Are we building the right product? [OK]

Hint: Validation checks the product's purpose, not the process [OK]

Common Mistakes:

• Confusing validation with verification
• Thinking validation checks code correctness
• Mixing up product quality with delivery timing

2. Which of the following best describes verification in software engineering?

easy

A. Checking if the software meets user needs

B. Testing the software with real users

C. Ensuring the software is built according to specifications

D. Planning the software development schedule

Solution

1. Step 1: Define verification

   Verification ensures the product is built correctly according to the design and requirements.

2. Step 2: Identify the matching option

   Ensuring the software is built according to specifications states ensuring the software is built according to specifications, which matches verification.

3. Final Answer:

   Ensuring the software is built according to specifications -> Option C

4. Quick Check:

   Verification = Built according to specs [OK]

Hint: Verification checks the process, not user needs [OK]

Common Mistakes:

• Confusing verification with validation
• Thinking verification involves user feedback
• Assuming verification is about project planning

3. Consider this scenario: A team tests if the software matches the design documents but ignores if the design meets user needs. Which activity are they performing?

medium

A. Project management

B. Requirements validation

C. User acceptance testing

D. Requirements verification

Solution

1. Step 1: Analyze the activity described

   The team checks if software matches design documents, focusing on correctness to specs.

2. Step 2: Match activity to concept

   This is verification, which ensures the product is built right, not necessarily the right product.

3. Final Answer:

   Requirements verification -> Option D

4. Quick Check:

   Checking against design = Verification [OK]

Hint: Verification checks specs, validation checks user needs [OK]

Common Mistakes:

• Confusing verification with validation
• Assuming user acceptance testing is verification
• Mixing project management with testing activities

4. A software team wrote requirements but forgot to check if they reflect user needs. What is the main problem here?

medium

A. Validation was skipped

B. Verification was skipped

C. Testing was incomplete

D. Design was incorrect

Solution

1. Step 1: Identify what was missed

   The team did not check if requirements reflect user needs, which is validation.

2. Step 2: Understand the impact

   Skipping validation risks building the wrong product, even if specs are correct.

3. Final Answer:

   Validation was skipped -> Option A

4. Quick Check:

   Missing user needs check = Validation skipped [OK]

Hint: Validation ensures user needs are met, not just specs [OK]

Common Mistakes:

• Confusing verification with validation
• Assuming testing covers validation
• Blaming design instead of requirements process

5. A project uses automated tools to check if code matches requirements and holds regular user reviews to confirm needs. What does this combination ensure?

hard

A. Both validation and verification are done

B. Only validation is done

C. Neither validation nor verification is done

D. Only verification is done

Solution

1. Step 1: Identify automated checks role

   Automated tools checking code against requirements perform verification.

2. Step 2: Identify user reviews role

   User reviews confirm if needs are met, which is validation.

3. Step 3: Combine both activities

   Doing both ensures the product is built right and is the right product.

4. Final Answer:

   Both validation and verification are done -> Option A

5. Quick Check:

   Automation + user reviews = Validation + Verification [OK]

Hint: Verification checks specs; validation checks user needs together [OK]

Common Mistakes:

• Thinking automated checks cover validation
• Assuming user reviews replace verification
• Believing one activity is enough alone