In the context of business analysis, the input status of requirements for undertaking requirement verification activities is 'Specified and Modeled'. This means that the requirements have been detailed and documented, and models have been created to represent them. This status is crucial for verification activities because it ensures that the requirements are clearly understood and can be systematically evaluated against quality standards to ensure they are usable for their intended purpose.

Validate requirements ensures that a set of requirements or designs delivers business value and supports the organization's goals and objectives.

Functional decomposition is a technique used to identify the elements and boundaries of the requirements architecture by breaking down complex processes or systems into smaller, more manageable parts. This method helps in understanding the system's functionality and the relationships between different components.
It allows business analysts to define a hierarchy of system functions and sub-functions, ensuring that all elements of the system are accounted for and that the scope of the project is clearly understood.
References: The concept of functional decomposition as a technique for defining requirements architecture is discussed in the Business Analysis Body of Knowledge (BABOK) guide, which serves as a standard for the practice of business analysis12.