ICS 121 Spring 2004

Instructor: Robbins

Assignment 3

Due: Tuesday, April 27 in Distribution Center

1. Estimation (1 point)

Effort estimation is the practice of making accurate estimates of how long it will take to complete a piece of work. Software developers are notoriously bad at this. You will practice by estimating how long it takes you to complete a task.

Calculate the error percentage: ((YOUR ACTUAL) - (YOUR ESTIMATE)) / (YOUR ESTIMATE)

TYPE YOUR ERROR PERCENTAGE HERE

2. Specification (4 points)

A. Which of the following describe differences between a user needs document and a software requirements specification (SRS) document. Delete the bullets that are incorrect, leaving only correct statements in the list.

• A user needs document informally says what users and customers say they want, whereas the SRS precisely defines the minimum that customers need.
• A user needs document says what users and customers say they want, whereas the SRS defines what the software vendor will build.
• The user needs document may contain items that logically conflict with each other, whereas the SRS must be logically consistent without contradictions.
• The user needs document is informal, whereas the SRS is a legal contract between the vendor and customers.
• User needs are read primarily by product managers, whereas the SRS is read just by developers.
• The user needs can describe product features that are not in the SRS.
• The SRS can describe product features that are not in the user needs.
• If a major change is made to the user needs, then the SRS would likely need to be updated as a result.
• If a major change is made to the SRS, then the user needs would likely need to be updated as a result.

B. Which of the following describe differences between an SRS and a design document. Delete the bullets that are incorrect, leaving only correct statements in the list.

• The SRS is what the customer thinks will be built, the design document is what will actual be built.
• The SRS is describes what will be built, whereas the design document describe how it will be built.
• The SRS can contain logical conflicts, whereas the design cannot.
• People in more departments at a software company would need to read the SRS than would need to read the design.
• People in more departments at a software company would need to help create the SRS than would need to help create the design.
• If a major change is made to the SRS, then the design would likely need to be updated as a result.
• If a major change is made to the design, then the SRS would likely need to be updated as a result.

3. UML Class Diagrams (5 points)

This diagram contains several errors in the use of the UML notation. List 5 mistakes and explain why each one is wrong.

TYPE YOUR ANSWER HERE: 5 SHORT PARAGRAPHS

4. UML Class Diagrams (5 points)

Describe in your own words the meaning of this UML class diagram. Be a precise as possible: describe each class and it's attributes, operations, and associations including multiplicity and aggregation.

TYPE YOUR ANSWER HERE: 1-3 PARAGRAPHS

5. UML Class Diagrams (5 points)

Consider the following description of credit card processing. (Note: this example is much simpler than real credit card processing.)

A credit card account is opened on a specific date with a 16-digit account number and a credit limit. Each credit card account belongs to a party. A party may be a corporation, a person, or a joint account between two people. A party has a billing address and telephone number. Several plastic cards may be issued for one account, but some corporate accounts do not have cards. Each account has a set of current transactions, with each transaction consisting of a date, dollar amount, and merchant name.

A. Draw a UML class diagram that represents the situation as precisely and completely as possible. Include, classes and/or interfaces, attributes, operations, associations, and generalizations and/or realizations. Specify association multiplicity and aggregation, but not navigability. Do not include visibilities. This is a design diagram that will be used by a programmer to guide implementation of the system.

USE ArgoUML OR Rational Rose TO MAKE A DIAGRAM, PRINT IT, AND STAPLE IT TO THESE PAGES.