Question

Identify and briefly describe four types of requirements that may be defined for a computerbased system

Short answer

The four types of requirements are functional, non-functional, technical, and business requirements.

Step-by-step solution

Define Functional Requirements

Functional requirements are the specific functions or tasks that a system must be able to perform. These requirements dictate how the system will interact with users, other systems, and processes. They detail the inputs, outputs, and behavior of the system's features and specify what the software should do, such as user authentication or data processing.

Specify Non-Functional Requirements

Non-functional requirements describe the performance characteristics and constraints of the system. These include aspects such as usability, reliability, scalability, and performance efficiency. Non-functional requirements focus on how the system performs rather than specific behaviors, for example, system response time or availability.

Identify Technical Requirements

Technical requirements outline the technical issues that must be considered to successfully implement the system. This can include programming languages, platforms, networking protocols, and system architecture. Technical requirements ensure that the system is designed within the necessary technical frameworks and technological standards.

Describe Business Requirements

Business requirements address the business needs driving the development of the system. These requirements explain why the system is being developed, capturing the high-level objectives that justify its creation. Business requirements are generally focused on fulfilling the organization's goals, such as increasing revenue or improving customer service.

Key concepts

Functional Requirements

Functional requirements define what the system should do. They are the core capabilities that a software system must provide, detailing the actions that the system should execute. These requirements specify interactions between the system and its users or other systems. Here are some aspects to consider with functional requirements:

• **Interactions**: How users will input data and how the system will output results.
• **Data Handling**: Processes like storing, processing, and retrieving data.
• **Error Management**: How the system should behave in the event of an error or issue.

For example, in an e-commerce platform, a functional requirement could be allowing users to add items to a shopping cart. Functional requirements are basically the "what" of a system — what the system should accomplish.

Non-Functional Requirements

Non-functional requirements focus on the quality attributes of a system. They address "how" the system should work and often dictate the user experience and system performance. They are crucial for determining user satisfaction and system robustness.

Consider these key non-functional aspects:

• **Performance**: The speed of operations, such as response time.
• **Reliability**: The system's ability to perform consistently over time.
• **Usability**: The ease with which users can learn and use the system.
• **Scalability**: How well the system can handle increased loads or expand to accommodate growth.

For example, in a booking system, a crucial non-functional requirement could be maintaining 99.9% uptime to ensure it's available anytime users want to book a service. Non-functional requirements ensure the system meets users' expectations beyond just functional correctness.

Technical Requirements

Technical requirements are centered on the technical constraints and choices that influence the development of a system. These requirements help pinpoint the technical environment in which the system will operate and include critical technological specifications.

Key areas to focus on with technical requirements include:

• **System Architecture**: The blueprint outlining how system components interact.
• **Programming Languages**: The languages in which the system will be written.
• **Hardware Requirements**: The hardware necessary to support the system's functionalities.
• **Integration**: How the system will integrate with existing technologies and platforms.

For instance, choosing a programming language like Python for a data analysis tool due to its robust libraries for data manipulation is a technical requirement consideration. Technical requirements ensure the system's design aligns with technology stacks and infrastructure capabilities.

Business Requirements

Business requirements are high-level descriptions of why a system is being developed. They focus on the strategic objectives that the system aims to fulfill within an organization. These requirements are tied to the business goals and expected outcomes, offering context for the system's existence.

Important aspects of business requirements include:

• **Objectives**: The goals the organization aims to achieve by developing the system.
• **Stakeholder Needs**: Considerations for what various stakeholders within the organization require.
• **Regulatory Compliance**: Ensuring the system meets industry regulations and standards.

As an example, a business requirement for a CRM system could be to enhance customer relationship management by improving data accuracy and access to client information. Business requirements set the stage for functional and non-functional needs, aligning the system with the organization's strategic vision.