Gathering Information and Use Case Scenarios

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Gathering Information and Use Case Scenarios
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Choices to get information

• Need to understand the current (as is) system,
  identify improvements, and develop the to-be
  system.
• How?
• Interviews
• Joint Application Design JAD
• Questionnaires
• Secondary Sources (document analysis)
• Observations

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Interviews -- Five Basic Steps

• Selecting Interviewees
• Designing Interview Questions
• Preparing for the Interview
• Conducting the Interview
• Post-Interview Follow-up

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Interview Preparation Steps

• Prepare General Interview Plan
• List of Question
• Anticipated Answers and Follow-Ups
• Confirm Areas of Knowledge
• Set Priorities in Case of Time Shortage
• Prepare the Interviewee
• Schedule
• Inform of Reason for Interview
• Inform of Areas of Discussion

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Conducting the Interview

• Appear professional and unbiased
• Record all information
• Check on organizational policy regarding tape
  recording
• Be sure you understand all issues and terms
• Separate facts from opinions
• Give interviewee time to ask questions
• Be sure to thank the interviewee
• End on time

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JAD Key Ideas

• Allows project managers, users, and developers to
  work together
• May reduce scope creep by 50
• Avoids requirements being too specific or too
  vague

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The JAD Session

• Tend to last 5 to 10 days over a three week
  period
• Prepare questions as with interviews
• Formal agenda and groundrules
• Facilitator activities
• Keep session on track
• Help with technical terms and jargon
• Record group input
• Help resolve issues
• Post-session follow-up

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Questionnaire Steps

• Selecting participants
• Using samples of the population
• Designing the questionnaire
• Careful question selection
• Administering the questionnaire
• Working to get good response rate
• Questionnaire follow-up
• Send results to participants

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Good Questionnaire Design
Begin with non-threatening and interesting
questions Group items into logically coherent
sections Do not put important items at the very
end of the questionnaire Do not crowd a page
with too many items Avoid abbreviations Avoid
biased or suggestive items or terms Number
questions to avoid confusion Pretest the
questionnaire to identify confusing
questions Provide anonymity to respondents
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Document Analysis

• Provides clues about existing as-is system
• Typical documents
• Forms
• Reports
• Policy manuals
• Look for user additions to forms
• Look for unused form elements

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Observation

• Users/managers often dont remember everything
  they do
• Checks validity of information gathered other
  ways
• Behaviors change when people are watched
• Careful not to ignore periodic activities
• Weekly Monthly Annual

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Selecting the Appropriate Techniques
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Creating Use Cases
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Elements of a Use Case

• Trigger -- event that causes the scenario to
  begin
• External trigger
• Temporal trigger
• All possible inputs and outputs
• Individual steps
• Show sequential order
• Show conditional steps

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Steps for building Use Cases

• Identify the use cases (think 3 to 9).
• Identify the major steps within each use case
  (think 3 to 9).
• Identify elements within steps.
• Confirm the use case.

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Ex. on-line university registration (exercise
D, pg. 167)
The system should enable the staff of each
academic department to examine the course offered
by their department, add and remove course, and
change the information about them (e.g., the
maximum number of students). It should permit
students to examine currently available courses,
add and drop courses to and from their schedules,
and examine the course for which they are
enrolled. Department staff should be able to
print a variety of reports about the courses and
the students enrolled in them. They system
should ensure that no student takes too many
course and that students who have any unpaid
fees are not permitted to register. (Assume that
a fees data store is maintained by the
university's financial office that the
registration system accesses but does not change.)
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Ex. real estate (exercise E, pg. 167)
A Real Estate Inc. (AREI) sells houses. People
who want to sell their houses sign a contract
with AREI and provide information on their house.
This information is kept in a database by AREI
and a subset of this information is sent to the
citywide multiple-listing service used by all
real estate agents. AREI works with two types of
potential buyers. Some buyers have an interest
in one specific house. In this case, AREI prints
information from its database, which the real
estate agent uses to help show the house to the
buyer (a process beyond the scope of the system
to be modeled). Other buyers seek AREIs advice
in finding a house that meets their needs. In
this case, the buyer completes a buyer
information form that is entered into a buyer
database, and AREI real estate agents use its
information to search AREIs database and the
multiple-listing service for houses that meet
their needs. The results of these searches are
printed and used to help the real estate agent
show houses to the buyer.
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