Exploratory Phase:

1. Read and understand the specification.
2. As you follow the steps below, walk through various scenarios to explore possibilities.  Record the results as Use Cases.

1. Extract noun phrases from the specification and build a list.
2. Look for nouns that may be hidden (for example, by the use of the passive voice) and add them to the list.
3. Identify candidate classes from the noun phrases by applying the following guidelines:
• Model physical objects.
• Model conceptual entities.
• Use a single term for each concept.
• Be wary of the use of adjectives.
• Model categories of objects/
• Model external interfaces.
• Model the values of an object's attributes.
4. Identify candidates for abstract superclasses by grouping the classes that share common attributes.
5. Use categories to look for classes that may be missing.
6. Write a short statement of the purpose of the class.

1. Find responsibilities using the following guidelines:
• Recall the purpose of each class, as implied by its name and specified in the statement and purpose.
• Extract responsibilities from the specification by looking for actions and information.
• Identify responsibilities implied by the relationships between classes.
2. Assign responsibilities to classes using the following guidelines:
• Evenly distribute system intelligence.
• State responsibilities as generally as possible.
• Keep behavior with related information.
• Keep information about one thing in one place.
• Share responsibilities among related classes.
3. Find additional responsibilities by looking for relationships between classes.
• Use "is-kind-of" relationships to find inheritance relationships.
• Use "is-analogous-to" relationships for find missing superclasses.
• Use "is-part-of" relationships to find other missing classes.

1. Find and list collaborations by examining the responsibilities associated with classes.  Ask:
• With whom does this class need to collaborate to fulfill its responsibilities?
• Who needs to make use of the responsibilities defined for this class?
2. Identify additional collaborations by looking for these relationships between classes:
• the "is-part-of" relationship,
• the "has-knowledge-of" relationship, and
• the "depends-upon" relationship.
3. Discard classes if no classes collaborate with them, and they collaborate with no other classes.