Solution Requirements (Functional and Non-Functional) - Complete Guide for CBAP Exam

Solution Requirements (Functional and Non-Functional): Complete Guide

Why Solution Requirements Are Important

Solution requirements form the foundation of successful business analysis and project delivery. Understanding the distinction between functional and non-functional requirements is critical because:

• Clarity and Alignment: They provide clear direction to development teams about what needs to be built and how it should perform
• Scope Management: Well-defined requirements prevent scope creep and help maintain project boundaries
• Quality Assurance: They establish the criteria against which solutions are tested and validated
• Stakeholder Communication: They bridge the gap between business needs and technical implementation
• Risk Reduction: Clear requirements minimize misunderstandings, rework, and project failures
• Resource Planning: They help teams estimate effort, timeline, and resource allocation accurately

What Are Solution Requirements?

Solution requirements describe what a solution must accomplish to address the identified business need. They are derived from stakeholder needs and are documented to guide development, testing, and implementation activities.

Solution requirements are divided into two primary categories:

Functional Requirements

Functional requirements specify what the solution must do. They describe the features, functions, and capabilities that the solution must provide to meet business objectives.

Characteristics of Functional Requirements:

• They describe specific behaviors or actions the system must perform
• They focus on features, capabilities, and functionality
• They answer the question: "What must the system do?"
• They are typically measurable and testable
• They directly address business needs
• Examples: user authentication, data processing, report generation, payment processing

Examples of Functional Requirements:

• The system shall allow users to login using email and password
• The system shall calculate monthly invoices based on usage data
• The system shall generate monthly reports in PDF format
• The system shall support bulk data import from CSV files
• The system shall enable users to search for products by category, price range, and availability

Non-Functional Requirements

Non-functional requirements specify how well the solution must perform. They describe quality attributes, constraints, and characteristics that define the overall performance, reliability, and user experience of the solution.

Characteristics of Non-Functional Requirements:

• They describe quality attributes and performance characteristics
• They focus on system behavior, reliability, security, and performance
• They answer the question: "How well must the system perform?"
• They are measurable but often less straightforward than functional requirements
• They apply across multiple functional requirements
• They represent constraints on the solution design and implementation

Common Types of Non-Functional Requirements:

• Performance: Response time, throughput, load capacity (e.g., "The system shall process 1,000 transactions per minute")
• Reliability: Availability, uptime, error rates (e.g., "The system shall maintain 99.9% availability")
• Scalability: Ability to handle growth (e.g., "The system shall support growth to 10 million users")
• Security: Data protection, authentication, authorization (e.g., "All data shall be encrypted using AES-256")
• Usability: User experience, accessibility, ease of use (e.g., "New users shall complete onboarding in less than 5 minutes")
• Maintainability: Code quality, documentation, support (e.g., "Code shall follow established style guidelines")
• Compatibility: Integration with other systems, browser support (e.g., "The system shall support Chrome, Firefox, Safari, and Edge browsers")
• Compliance: Legal and regulatory requirements (e.g., "The system shall comply with GDPR requirements")
• Portability: Ability to run on different platforms (e.g., "The application shall run on iOS and Android")

How Functional and Non-Functional Requirements Work Together

Integration and Interdependence:

Functional and non-functional requirements work together to create a complete solution specification:

• Functional requirements define the scope: What features and capabilities are needed
• Non-functional requirements define the quality: How well those features must perform
• Together they ensure: The solution is both capable and effective

Example of How They Work Together:

Functional Requirement: "The e-commerce system shall process customer orders and update inventory in real-time."

Related Non-Functional Requirements:

• Performance: "Order processing shall complete within 2 seconds"
• Reliability: "The system shall maintain 99.95% uptime during peak hours"
• Security: "Payment information shall be encrypted using PCI-DSS standards"
• Scalability: "The system shall handle up to 10,000 concurrent users"
• Usability: "Users shall complete checkout in less than 3 minutes on average"

How Solution Requirements Are Developed

Process Overview:

1. Gather Stakeholder Needs: Conduct interviews, workshops, and analysis to understand business problems
2. Analyze and Prioritize: Organize needs and identify which are most critical
3. Define Functional Requirements: Specify what the solution must do to address needs
4. Define Non-Functional Requirements: Specify quality attributes and performance criteria
5. Document Requirements: Create clear, measurable requirement statements
6. Review and Validate: Ensure requirements are complete, consistent, and testable
7. Baselined for Traceability: Establish a baseline for change control and traceability



Characteristics of Well-Defined Solution Requirements




Effective solution requirements should be:

• Clear: Written in language understandable to all stakeholders
• Complete: Sufficient to guide development without excessive rework
• Correct: Accurately reflecting stakeholder needs and business objectives
• Consistent: Not conflicting with other requirements
• Verifiable/Testable: Able to be validated through testing or inspection
• Traceable: Linked to business needs and design elements
• Prioritized: Ranked by importance and urgency
• Feasible: Achievable within time, budget, and technical constraints
• Necessary: Not redundant or unnecessary



Common Challenges in Defining Solution Requirements



• Ambiguity: Vague language that allows different interpretations
• Scope Creep: Undisciplined addition of requirements beyond original scope
• Conflicting Requirements: Requirements that contradict each other
• Missing Non-Functional Requirements: Focus on "what" without considering "how well"
• Unmeasurable Requirements: Subjective criteria that cannot be objectively verified
• Lack of Stakeholder Involvement: Requirements developed without sufficient input from those who will use the solution
• Premature Design Decisions: Requirements that constrain design unnecessarily



How to Answer Exam Questions on Solution Requirements




Types of Exam Questions




CBAP exam questions on solution requirements typically fall into these categories:




1. Identification Questions: Identifying whether a requirement is functional or non-functional




Example: "Which of the following is a non-functional requirement? A) The system shall process customer payments, B) The system shall process payments within 3 seconds, C) The system shall store customer data, D) The system shall generate invoices"




Answer: B - This specifies performance, which is a non-functional characteristic.




2. Application Questions: Applying knowledge to new scenarios




Example: "You are gathering requirements for a mobile banking application. Which approach would best capture both functional and non-functional requirements? A) Ask only what features users want, B) Conduct interviews about features and performance expectations, C) Review only technical specifications, D) Focus only on security requirements"




Answer: B - This balanced approach captures both types of requirements.




3. Best Practice Questions: Identifying best practices in requirements management




Example: "When defining non-functional requirements, which characteristic is MOST important? A) They should be general and aspirational, B) They should be specific, measurable, and testable, C) They should describe the user interface design, D) They should be kept separate from functional requirements"




Answer: B - Non-functional requirements must be concrete and verifiable.




4. Scenario Questions: Analyzing situations and selecting appropriate approaches




Example: "Your team has defined that the system must "be user-friendly." This is a poor non-functional requirement because it is not measurable. How should you improve this requirement? A) Delete it, B) Replace it with "The system shall be intuitive," C) Define specific usability criteria such as "new users shall complete key tasks in less than 5 minutes with 95% success rate," D) Add it to functional requirements"




Answer: C - This converts a vague requirement into specific, measurable criteria.




Exam Tips: Answering Questions on Solution Requirements (Functional and Non-Functional)




Tip 1: Remember the Core Distinction




Functional = WHAT; Non-Functional = HOW WELL



• If a requirement describes a feature or capability → It's likely functional
• If a requirement describes performance, quality, or a constraint → It's likely non-functional
• Use these keywords to help identify:
• Functional keywords: shall do, shall perform, shall support, shall enable, shall allow
• Non-functional keywords: shall be (quality), shall have (quality), response time, availability, reliability, security, performance, scalability



Tip 2: Look for Measurable Criteria




Well-defined requirements, especially non-functional ones, must be measurable and testable:



• Look for specific numbers: "2 seconds," "99.9%," "1,000 users"
• Vague terms like "fast," "user-friendly," "reliable" are NOT properly defined requirements
• If you see a question asking to improve a requirement, often the answer involves making it more specific and measurable



Tip 3: Understand the Relationship Between Functional and Non-Functional Requirements




Remember that:



• Non-functional requirements apply across multiple functional requirements
• A single non-functional requirement (like "99.9% availability") affects all functions of the system
• Questions may test your understanding of how they complement each other
• Good solutions address both what needs to be done and how well it should be done



Tip 4: Recognize Common Non-Functional Requirement Categories




Familiarize yourself with common types:



• Performance: Response time, throughput, processing speed
• Reliability: Uptime, mean time between failures, failure recovery
• Security: Data encryption, access control, authentication
• Scalability: Ability to handle growth, concurrent users
• Usability: Ease of use, learning curve, accessibility
• Compliance: Regulatory, legal, industry standards
• Compatibility: Integration with other systems, browser support
• Maintainability: Code quality, documentation, support



Questions often provide scenarios where you must identify these categories.




Tip 5: Be Aware of Common Pitfalls




Avoid these common mistakes:

• Confusing design with requirements: "The system shall use a database" is a design decision, not a requirement. The requirement is what the system must do with data.
• Missing non-functional requirements: Don't assume only functional requirements are needed. Questions often test whether you recognize the importance of non-functional requirements.
• Overly specific solutions: Requirements should focus on the "what" not the "how to implement it."
• Unmeasurable requirements: If a requirement can't be tested, it's not well-defined.



Tip 6: Approach Classification Questions Systematically




When asked to classify a requirement:



1. Read carefully: Identify the key characteristics being specified
2. Ask: "Does this describe what the system does?" → Functional
3. Ask: "Does this describe a quality, performance, or constraint?" → Non-functional
4. Check for measurable criteria: Non-functional requirements need quantifiable metrics
5. Consider context: How does this requirement relate to others?



Tip 7: Practice Rewriting Vague Requirements




Exam questions often ask you to improve poor requirements. Practice converting:




Vague: "The system shall be fast."
Better: "The system shall respond to user queries within 2 seconds 95% of the time."




Vague: "The system shall be secure."
Better: "The system shall encrypt all data in transit using TLS 1.3 and at rest using AES-256 encryption."




Vague: "The system shall be reliable."
Better: "The system shall maintain 99.95% uptime with a maximum of 4 hours unscheduled downtime per year."




Tip 8: Understand Traceability




Requirements must be traceable:

• Each solution requirement should trace back to a business need or stakeholder requirement
• Each requirement should be traceable forward to design elements and test cases
• Questions may ask about impact of requirement changes - understand that all requirements must be managed together



Tip 9: Remember the Role of Business Analyst




When answering questions:

• The BA's role is to define requirements clearly, not to make design decisions
• Requirements should be independent of implementation - avoid prescribing specific technologies or approaches
• Both functional and non-functional requirements are the BA's responsibility
• Stakeholder input is critical for both types of requirements



Tip 10: Practice with Real Scenarios




Example Scenario Practice:




"Your organization is developing an online reservation system for restaurants. Identify which of these are functional vs. non-functional requirements:



• The system shall allow customers to view available time slots - FUNCTIONAL (what it does)
• The system shall display available time slots within 1 second - NON-FUNCTIONAL (performance)
• The system shall send confirmation emails to customers - FUNCTIONAL (what it does)
• The system shall send emails within 5 minutes of booking - NON-FUNCTIONAL (performance/timing)
• The system shall support 10,000 concurrent users - NON-FUNCTIONAL (scalability)
• The system shall allow restaurant staff to modify menu items - FUNCTIONAL (what it does)
• The system shall encrypt customer payment information - NON-FUNCTIONAL (security)



Key Takeaways



• Solution requirements specify what the solution must accomplish and how well it must perform
• Functional requirements describe the features and functions the solution must provide
• Non-functional requirements describe the quality attributes and constraints on the solution
• Both types are essential and must work together for a complete solution specification
• Well-defined requirements are clear, complete, correct, consistent, and verifiable
• Non-functional requirements must be specific and measurable, not vague or aspirational
• Understanding the distinction and the relationship between functional and non-functional requirements is critical for CBAP success
• On exam questions, distinguish based on: Functional answers "what?", Non-functional answers "how well?"
• Be prepared to identify requirements, classify them, improve vague requirements, and explain their importance