## 3 Research Methodology
### Construction of SRs Information Extraction Templates  
The information extraction templates serve as the core foundation for enabling large language models to perform information extraction tasks, and their completeness directly impacts the accuracy and reliability of the extracted information. To achieve the precise extraction of information from different categories of system requirements (SRs), this paper designs corresponding structured information extraction templates based on the five requirement labels defined by SysML. Each template clearly defines the key information \begin{table}
\begin{tabular}{c c c} \hline
**Requirement Category** & **Description** & **Example** \\ \hline Functional Requirement & Describes the functions or behaviors that the system must have and which are necessary to meet user needs. & The automatic fare collection system should have user permission management functionality. \\ \hline Interface Requirement & Defines the interaction methods between the system and external systems or components, involving data transmission, signal exchange, physical connections, etc. & The automatic fare collection system should implement interfaces with relevant systems. \\ \hline Performance Requirement & Defines the performance metrics the system should achieve when performing functions, such as speed, accuracy, etc., usually & The automatic fare collection system equipment should be capable of continuous 24 h operation. \\ \hline Physical Requirement & Describes the physical properties and components of the system, including size, materials, and constituent elements. & The tickets must include one-way, stored-value, and other types of tickets as required. \\ \hline Design Constraint & Specifies the particular rules and restrictions that must be followed in the system design, including technical standards, laws, regulations, and environmental factors. & The design of the network automatic fare collection system should follow the basic principles of centralized management, hierarchical control, and resource sharing. \\ \hline \end{tabular}
\end{table} 
Table 1: Five types of requirements and their descriptions and examples. elements that should be present for each requirement type, aiming to ensure consistency and completeness in the extraction process. The design of these templates is based on a comprehensive analysis of the requirement categories, thoroughly considering the unique characteristics and shared attributes of various requirements in complex system design, ensuring the accurate extraction of the core components of each requirement category from the requirement documents. The elements within the templates encompass various types of characteristic information, including the following:  
**Subject:** The subject of each requirement represents the initiator, executor, or the primary system components involved. In the five types of requirements, the subject is a core component that clarifies the responsible party or related system elements, helping to define the key roles and their functions within the requirement. In the process of requirement data extraction using large language models, the subject is a necessary information element. **Attribute:** In some SRs, in addition to the subject, specific attributes related to the subject may also appear, typically expressed in the form of \"AA's BB\", where BB is the core subject of the requirement. These attributes are used to further describe the specific characteristics or functionalities of the subject. **Object:** In SRs, the object is the target entity involved when the subject performs certain actions or behaviors. It refers to the specific thing or system component that the described operation or function in the requirement acts upon. **Action:** In the requirement document, the action refers to the operation or action performed by the subject on the object, specifically describing the interaction between the subject and the object.