Correctness, Completeness, and Consistency

Correctness, Completeness, and Consistency in Requirements Analysis and Design Definition

Introduction

In the CBAP (Certified Business Analyst Professional) examination, understanding Correctness, Completeness, and Consistency is crucial for the Requirements Analysis and Design Definition domain. These three fundamental principles form the foundation of quality requirements that drive successful project outcomes.

Why Is This Important?

Quality requirements are essential because they:

• Reduce project risk: Clear, complete requirements minimize misunderstandings and scope creep
• Improve communication: Well-defined requirements ensure all stakeholders understand project objectives
• Enhance quality: Correct and consistent requirements lead to better solutions that meet actual business needs
• Control costs: Defects caught early in requirements phase are far less expensive to fix than during development or after deployment
• Enable traceability: Complete requirements allow tracking from business need through design and testing

What Are Correctness, Completeness, and Consistency?

1. Correctness

Definition: Requirements are correct when they accurately reflect what the business actually needs and what stakeholders truly require.

Key Characteristics:

• Accurately represents the business need or problem
• Reflects stakeholder intent without misinterpretation
• Aligns with organizational strategy and goals
• Is technically feasible and realistic
• Can be verified and validated against actual business needs

Example: A requirement stating "The system shall process transactions in under 2 seconds" is correct if this timeframe actually matches business operational needs. If the business can tolerate 5-second processing, this requirement is incorrect.

2. Completeness

Definition: Requirements are complete when they fully describe what is needed to address the business problem without omissions or gaps.

Key Characteristics:

• Covers all necessary functionality and features
• Includes all relevant constraints and assumptions
• Addresses all user types and use cases
• Specifies success criteria and acceptance conditions
• Includes performance, security, and compliance requirements
• Details data requirements and business rules

Example: A requirement for a customer portal should include requirements for new customer registration, existing customer login, account management, AND security measures. Omitting security requirements makes the specification incomplete.

3. Consistency

Definition: Requirements are consistent when they do not contradict each other and align across the entire requirements specification.

Key Characteristics:

• No conflicting requirements or contradictory statements
• Uniform terminology and definitions throughout
• Aligned priority and scope across related requirements
• Coherent in structure and presentation
• Harmonized with existing systems and processes

Example: Having one requirement that states "The system shall reject all transactions over $10,000" and another stating "The system shall accept all valid transactions up to $50,000" creates inconsistency that must be resolved.

How These Principles Work Together

These three principles are interdependent:

• Correctness without Completeness: You may have correct requirements that don't cover the entire scope, leaving gaps in understanding
• Completeness without Correctness: You may have all requirements needed, but some reflect wrong business needs
• Consistency without Correctness: Requirements may not contradict each other but collectively be wrong
• All Three Together: Create a robust foundation for successful project delivery

How to Evaluate Requirements for C3 (Correctness, Completeness, Consistency)

Step 1: Review Against Business Objectives

For Correctness:

• Verify each requirement against documented business needs
• Validate with stakeholder interviews and workshops
• Check alignment with organizational strategy
• Confirm technical feasibility with architects and developers

Step 2: Perform Traceability Analysis

For Completeness:

• Create traceability matrix linking requirements to business needs
• Verify all user roles and use cases are addressed
• Check non-functional requirements (performance, security, compliance)
• Review acceptance criteria for each requirement

Step 3: Conduct Requirements Review

For Consistency:

• Check for conflicting or contradictory requirements
• Verify consistent terminology and definitions
• Review priority and scope alignment
• Ensure cross-functional requirements alignment

Common Issues and How to Address Them

Incorrect Requirements

Issues: Requirements that misrepresent business needs, are not achievable, or don't align with strategy

Solutions:

• Conduct stakeholder validation sessions
• Perform requirements walkthrough with business sponsors
• Include subject matter experts in review process
• Document assumptions and get stakeholder sign-off

Incomplete Requirements

Issues: Missing requirements for certain users, scenarios, or non-functional aspects

Solutions:

• Develop comprehensive use case or user story inventory
• Create requirement allocation sheets for each functional area
• Include explicit non-functional requirement categories
• Use requirements templates to ensure completeness

Inconsistent Requirements

Issues: Contradictory requirements, varying terminology, conflicting scopes

Solutions:

• Establish and maintain a requirements glossary
• Use consistent requirement structure and format
• Perform automated consistency checks with requirements tools
• Resolve conflicts through impact analysis and stakeholder negotiation

Exam Tips: Answering Questions on Correctness, Completeness, and Consistency

Tip 1: Understand the Definitions Clearly

Before the exam, memorize and thoroughly understand each concept:

• Correctness: Accuracy to business needs
• Completeness: Coverage without gaps
• Consistency: No contradictions or conflicts

Practice distinguishing between them in different scenarios.

Tip 2: Identify the Question Type

Exam questions typically ask you to:

• Identify defects: "Which requirement has a correctness issue?"
• Choose solutions: "How would you ensure completeness?"
• Recognize scenarios: "Which situation demonstrates inconsistency?"

Read carefully to determine what type of question is being asked.

Tip 3: Look for Red Flags in Scenario Questions

For Correctness Issues:

• Requirements that don't match stated business objectives
• Unrealistic or infeasible requirements
• Requirements that contradict known constraints
• Statements about what the system shouldn't do (instead of should)

For Completeness Issues:

• Missing user roles or personas
• Absent non-functional requirements (performance, security, compliance)
• No acceptance criteria or success measures
• Gaps in exception handling or error scenarios

For Consistency Issues:

• Contradictory statements about the same feature
• Conflicting priority assignments
• Inconsistent terminology or definitions
• Different treatment of similar scenarios

Tip 4: Use the SMART Criteria Check

When evaluating requirements in exam questions, remember requirements should be:

• S - Specific (not vague)
• M - Measurable (quantifiable)
• A - Achievable (feasible)
• R - Relevant (to business need)
• T - Traceable (linked to source)

This framework helps identify correctness and completeness issues.

Tip 5: Practice With Examples

Example Scenario 1 - Correctness:

Requirement: "The system shall store customer data in a proprietary format to prevent competitor access."

Analysis: This requirement is incorrect because it addresses a security concern with an improper solution. Correctness requires aligning with actual business needs (data protection) using appropriate means.

Example Scenario 2 - Completeness:

Requirements: Only functional requirements are documented. Non-functional requirements (response time, uptime, scalability) are missing.

Analysis: The specification is incomplete because critical non-functional aspects are not addressed.

Example Scenario 3 - Consistency:

Requirement A: "All user passwords must be minimum 12 characters."
Requirement B: "The system shall accept passwords of 8 or more characters."

Analysis: These requirements are inconsistent and contradict each other.

Tip 6: Know the Elicitation and Validation Techniques

Exam may ask how to ensure C3. Know these techniques:

• Interviews and workshops: Verify correctness with stakeholders
• Traceability matrix: Ensure completeness and consistency
• Requirements review: Identify all three types of issues
• Prototyping: Validate correctness of understanding
• Requirements management tools: Track consistency automatically

Tip 7: Answer Structure for Complex Questions

When answering scenario-based questions:

• First: Identify which C3 principle(s) are at issue
• Second: Explain why the principle is violated
• Third: Suggest how to correct or improve the situation
• Fourth: Reference relevant elicitation or validation techniques

Tip 8: Watch for Multi-Principle Questions

Some questions may involve multiple principles. For example:

Question: "A requirements document includes all functional needs but several stakeholders disagree about feature priority, and one requirement contradicts another about data validation."

Issues: Completeness (all functions covered), Consistency (conflict between requirements), AND Correctness (stakeholder disagreement suggests incorrect understanding)

Identify all issues, not just one.

Tip 9: Know the Business Analyst's Role

Understand your responsibility in ensuring C3:

• You must elicit requirements correctly (correctness)
• You must document all aspects comprehensively (completeness)
• You must organize requirements consistently (consistency)
• You must review and validate with stakeholders throughout

Questions often ask what action you should take as BA.

Tip 10: Review Quality Attributes

Study other requirement quality attributes that work with C3:

• Clarity: Requirements are understandable
• Feasibility: Requirements are achievable
• Necessity: Requirements are needed
• Verifiability: Requirements can be tested

Understanding the broader context of requirement quality strengthens C3 understanding.

Practice Question Examples

Question 1: "A business analyst is reviewing requirements for a new e-commerce platform. The document includes detailed functional requirements for product search and purchase, but no requirements for data security, payment processing compliance, or system performance. What quality characteristic is missing?"

Answer: Completeness - Non-functional requirements and critical compliance aspects are not addressed.

Question 2: "Which of the following approaches would BEST ensure consistency in a requirements specification?"

• A) Interviewing as many stakeholders as possible
• B) Establishing a requirements glossary and using a standard template format
• C) Documenting all requirements without prioritization
• D) Having architects review requirements

Answer: B - Standardization and consistent terminology directly support consistency.

Question 3: "A requirement states: 'The system shall be fast.' This requirement lacks which characteristic?"

Answer: Correctness and Completeness - "Fast" is subjective (not verifiable), and specific performance metrics are missing. The requirement doesn't clearly reflect actual business performance needs.

Key Takeaways

• Correctness ensures requirements match actual business needs
• Completeness ensures all necessary aspects are included
• Consistency ensures no contradictions or conflicts
• All three work together to create quality requirements
• The business analyst is responsible for establishing and maintaining C3
• Multiple techniques (interviews, reviews, traceability, tools) support C3
• Exam questions test your ability to identify C3 issues and recommend solutions
• Practice distinguishing between the three principles in various scenarios
• Always validate requirements with stakeholders to ensure correctness
• Use structured approaches and tools to support completeness and consistency

Conclusion

Mastering Correctness, Completeness, and Consistency is essential for CBAP exam success and professional effectiveness as a business analyst. These three principles form the backbone of quality requirements that lead to successful projects. By understanding their definitions, recognizing violations, and knowing how to address them, you'll be well-prepared for exam questions and equipped to deliver superior business analysis in practice.