non-functional requirement: Business Analysis Explained

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non-functional requirement: Business Analysis Explained

In the realm of business analysis, the term ‘non-functional requirement’ holds a significant place. It refers to the criteria that judge the operation of a system, rather than specific behaviors. This article will delve into the intricate details of non-functional requirements, their importance in business analysis, and how they influence the overall performance of a business system.

Non-functional requirements, often abbreviated as NFRs, are the requirements that specify criteria to evaluate the performance of a system. They are the standards for the system’s operation, not its behavior, which is why they are often referred to as ‘quality of service’ requirements.

Understanding Non-Functional Requirements

Non-functional requirements are the aspects of a system that do not perform a specific function or task. Instead, they serve to define the system’s ‘how’ rather than its ‘what’. They describe how well the system performs its functions, rather than what it does. This can include aspects such as reliability, scalability, usability, etc.

These requirements are often much harder to define and measure than functional requirements. They are also often much more critical to the success of a project. If a system meets all of its functional requirements but fails to meet its non-functional requirements, it is unlikely to be successful.

Types of Non-Functional Requirements

Non-functional requirements can be broadly categorized into two types: execution qualities, such as security and usability, and evolution qualities, like testability, maintainability, extensibility, and scalability. Execution qualities are observable during operation, while evolution qualities are embodied in the static structure of the software system.

It’s important to note that the specific types of non-functional requirements will vary greatly depending on the nature of the system being developed. For example, a system that is intended to handle sensitive information may have security as a major non-functional requirement.

Importance of Non-Functional Requirements in Business Analysis

Non-functional requirements play a crucial role in business analysis. They are the factors that influence customer satisfaction and system performance. They ensure that the system is usable, reliable, and meets the business’s operational requirements.

Moreover, non-functional requirements also help in decision-making processes during system development. They provide a clear understanding of the system’s operational constraints and help the development team to design a system that meets both the functional and non-functional requirements.

Identifying Non-Functional Requirements

Identifying non-functional requirements is an essential part of the business analysis process. These requirements are not always explicitly stated by the stakeholders, and it is the responsibility of the business analyst to elicit them.

There are several techniques that can be used to identify non-functional requirements. These include interviewing stakeholders, conducting surveys, and using templates or checklists. The choice of technique will depend on the nature of the project and the specific needs of the stakeholders.

Challenges in Identifying Non-Functional Requirements

Identifying non-functional requirements can be a challenging task. Unlike functional requirements, which are usually clearly defined and easy to understand, non-functional requirements can be vague and difficult to quantify. This makes them harder to identify and manage.

Another challenge is that non-functional requirements often conflict with each other. For example, improving system performance may require more resources, which could conflict with a requirement for the system to be cost-effective. Balancing these conflicting requirements is a key part of the business analyst’s role.

Strategies for Identifying Non-Functional Requirements

Despite the challenges, there are several strategies that can be used to effectively identify non-functional requirements. One approach is to use a structured method for eliciting requirements, such as the Volere Requirements Specification Template. This template provides a systematic way to identify and document non-functional requirements.

Another strategy is to involve all relevant stakeholders in the requirements elicitation process. This includes not only the end users of the system, but also the system administrators, the development team, and any other parties who will be affected by the system. By involving all stakeholders, the business analyst can ensure that all relevant non-functional requirements are identified.

Managing Non-Functional Requirements

Once non-functional requirements have been identified, they must be managed effectively. This involves prioritizing the requirements, documenting them in a clear and understandable way, and ensuring that they are met during the system development process.

Managing non-functional requirements can be a complex task, as these requirements often conflict with each other and with functional requirements. However, with careful planning and effective communication, it is possible to ensure that all requirements are met.

Tools for Managing Non-Functional Requirements

There are several tools available that can help in managing non-functional requirements. These tools can help in documenting the requirements, tracking their progress, and ensuring that they are met. Some of these tools include requirements management software, project management software, and business process modeling tools.

Using these tools can help to ensure that non-functional requirements are not overlooked during the system development process. They can also help to prevent conflicts between requirements and ensure that all requirements are met.

Best Practices for Managing Non-Functional Requirements

There are several best practices that can be followed when managing non-functional requirements. One of these is to clearly document all non-functional requirements and their associated metrics. This can help to ensure that all stakeholders have a clear understanding of what is required.

Another best practice is to regularly review and update the non-functional requirements as the project progresses. This can help to ensure that the requirements remain relevant and achievable, and that any changes to the project or its environment are taken into account.


Non-functional requirements are a critical part of any system development project. They define the ‘how’ of a system, and are often the factors that determine whether a project is successful or not. As such, they must be carefully identified, managed, and met.

By understanding the importance of non-functional requirements, and by using effective strategies and tools to manage them, business analysts can help to ensure that their projects are successful and that their systems meet the needs of their stakeholders.