A functional requirements specification (FRS) is a document that defines what features and functions a system should provide to meet the business needs and objectives. It describes how users will interact with the system and what outcomes they expect from it. An FRS typically includes use cases, user stories, acceptance criteria, data models, business rules, workflows, diagrams, mockups, and other details that describe how the system should work. A BA should create an FRS to define the enhancement features for the current Salesforce CPQ implementation that must be configured in the next phase of the project. Reference: https://trailhead.salesforce.com/en/content/learn/modules/business-analysis-functional-requirements/understand-functional-requirements