|  |  |  |  |  |  |  |  |  |  |  | 
   
    | ¨ | Smallest
    Effective Group of Requirements 
 |  | 
   
    |  | 
   
    | ¨ | Contains
    List of Evaluatable Statements 
 |  | 
   
    |  | 
   
    |  | called
    “Elements” 
 |  | 
   
    |  | 
   
    |  | – | Component
    is like a phrase in natural language 
 | 
   
    |  | 
   
    |  | – | Element
    is like a word in the phrase 
 |  | 
   
    |  | 
   
    | ¨ | Component
    may have multiple “levels” 
 |  | 
   
    |  | 
   
    |  | – | Each
    could contain more functions, or 
 |  | 
   
    |  | 
   
    |  | – | Each
    could extend functions to more users 
 |  |