Functional Requirements vs. Technical Requirements

Attribute	Functional Requirements	Technical Requirements
Definition	Describes what the system should do	Describes how the system should do it
Focus	User needs and business goals	Technology and implementation details
Language	Written in natural language	Written in technical language
Stability	May change over time based on user feedback	Should be stable and not change frequently
Measurability	Can be measured based on user satisfaction	Can be measured based on performance metrics

Definition

Functional requirements are specifications that define the functions or features a system must have in order to meet the needs of its users. These requirements describe what the system should do. On the other hand, technical requirements are specifications that define the technical aspects of how a system will be built and implemented. These requirements detail how the system will be developed, deployed, and maintained.

Focus

Functional requirements focus on the behavior of the system from a user's perspective. They outline the specific tasks the system must perform, the interactions between the system and its users, and the outputs the system must produce. Technical requirements, on the other hand, focus on the technology and infrastructure needed to support the system. They address issues such as performance, scalability, security, and integration with other systems.

Stakeholders

Functional requirements are typically defined by business stakeholders, end users, and other non-technical members of the project team. These requirements are based on the needs and expectations of the users and are often expressed in terms that are easy for non-technical stakeholders to understand. Technical requirements, on the other hand, are usually defined by technical stakeholders such as developers, architects, and system administrators. These requirements are more detailed and specific, focusing on the technical aspects of the system.

Flexibility

Functional requirements are often more flexible and subject to change throughout the project lifecycle. As users provide feedback and new requirements emerge, functional requirements may need to be adjusted to accommodate these changes. Technical requirements, on the other hand, are typically more rigid and less prone to change. Once technical decisions are made and implemented, they are more difficult to modify without significant impact on the project.

Measurability

Functional requirements are usually easier to measure and test than technical requirements. Since functional requirements describe the system's behavior and outputs, they can be validated through user testing and acceptance criteria. Technical requirements, on the other hand, may be more difficult to measure directly. They often involve complex technical specifications and performance metrics that require specialized tools and expertise to evaluate.

Dependencies

Functional requirements are often dependent on technical requirements for implementation. In order to deliver the desired functionality, the system must meet certain technical constraints and requirements. For example, if a functional requirement calls for real-time data processing, the system must have the necessary hardware and software capabilities to support this functionality. Technical requirements, on the other hand, may not always be directly tied to specific functional requirements. They may be driven by technical considerations such as security, performance, or compliance.

Documentation

Functional requirements are typically documented in user stories, use cases, and other user-centric formats that describe the system's behavior in a narrative form. These documents are often written in plain language and focus on the user's perspective. Technical requirements, on the other hand, are usually documented in technical specifications, architecture diagrams, and other technical artifacts that describe the system's implementation details. These documents are more detailed and may require specialized knowledge to interpret.

Conclusion

In conclusion, functional requirements and technical requirements play complementary roles in the development of a system. Functional requirements define what the system should do from a user's perspective, while technical requirements define how the system will be built and implemented. Both types of requirements are essential for the successful delivery of a system that meets the needs of its users and operates effectively within its technical environment.