Chapter 10 Fact-Finding Techniques

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Chapter 10 Fact-Finding Techniques

• CS 522 Fall 2001

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Special Topic A Comparison of Development Model
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Special Topics Types of Development Models

• The Waterfall Development Model
• The Spiral Model
• The Iterative Development Model

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The Waterfall Development Model

• Characteristics
• Encouraging to gather and define system
  requirements.
• Breaking the complex mission of development into
  several logical steps (analysis, design, code,
  test, and so forth) Divide and conquer
  approach.
• Ensuring each step is executed properly with good
  quality deliverable, validation, entry, and exit
  criteria for each step.

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The Waterfall Development Model

• Advantages
• Enabling tracking of project progress more
  accurately and uncovering possible slippages
  early.
• Focusing the organization that develops the
  software system to be more structured and
  manageable.
• Disadvantages
• The process could become too rigid to be
  efficient and effective.

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The Spiral Model

• Developed by Boehm in 1988
• Characteristics
• Relying heavily on prototyping and risk
  management vs. the document-driven approach of
  the waterfall approach.
• Foe each portion of the project and for each of
  its levels of elaboration, the same sequence of
  steps (cycle) is involved. For instance, the
  concept of software requirements, to design, and
  implementation, each involves a spiral cycle.

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The Spiral Model

• Approach
• The first step of each cycle is to identify the
  objective of the portion of the product being
  elaborated, the alternative means of
  implementation of the portion of the product, and
  the constraints imposed on the application of the
  alternatives.
• The next step is to evaluate the alternatives
  relative to the objectives and constraints and to
  identify the associated risks and resolve them.
• In addition to prototyping for risk analysis, the
  spiral model also simulations, models, and
  benchmarks in order to reach the best
  alternatives.

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Development Team
Project Lead
Developer
Tester
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The Iterative Development Model

• Characteristics
• Begin with a subset of the requirements and
  develop a subset of the product that satisfies
  the essential needs of the users.
• Based on the analysis of each immediate product,
  the requirements and design are modified over a
  series of iterations to provide a system to the
  user that meets evolving customer needs with
  improved design based on feedback and testing.
• Combine with prototyping with the strength of the
  classical waterfall model.

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The Iterative Development Model

• Supporting the iterative development was the
  small team approach in which each team assumed
  the full responsibility of the system.

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Sampling and Investigating Hard Data
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Topics

• The Needs for Sampling
• Sampling Design
• Kinds of Information Sought in Investigation

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The Needs for Sampling

• Containing costs
• Speeding up the data gathering
• Improving effectiveness
• Reducing bias

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Sampling Design

• Four steps
• Determine the data to be collected or described
• Determine the population to be sampled
• Choose the type of sample
• Decide on the sample size

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Kinds of Information Sought in Investigation

• Types of hard Data (other than interviewing and
• Observation)
•  Analyzing Quantitative Documents
• Reports used for decision making
• Performance reports
• Records
• Data capture forms

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Kinds of Information Sought in Investigation

• 2.  Analyzing Qualitative Documents
• Memos
• Signs on bulletins boards or in work areas
• Corporate Web sites
• Manuals
• Policy handbooks

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Interviewing
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Topics

• Five Steps in Interview Preparation
• Two Types of Questions Open-End vs. Closed
  Questions
• Three Basic ways of Structuring Interviews
• JAD (Joint Application Design (Development))

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Five Steps in Interview Preparation

• Reading background material
• Establishing interview objectives
• Deciding when to interview
• Preparing the interviewee
• Deciding on question type and structure

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Two Types of Questions Open-End Questions vs.
Closed Questions

• Open-ended interview questions
• Open describes the interviewees options for
  responding.
• They are open.
• Advantages
• Putting the interviewee at ease
• Allowing more spontaneity
• Disadvantages
• Possibly losing control of the interview
• May not get the types of answers you want

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Two Types of Questions Open-End Questions vs.
Closed Questions

• Closed interview questions
• Such as How many subordinates do you have?
• Benefits
• Getting to relevant data
• Keeping control over the interview
• Drawbacks
• Failing to obtain rich detail
• Intimidating the interviewee

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Three Basic ways of Structuring interviews

• Pyramid Structure Starting from closed
  questions, then gradually expand into open
  territory.
• Funnel Structure The reverse of pyramid
  structure approach.
• Diamond-Shaped A combination of the two above
  structures.

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JAD (Joint Application Development)
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JAD (Joint Application Development) vs.
Traditional Way of Gathering Requirements

• JAD sessions (also called facilitated session)
  are used to gather information and feedback and
  confirm the results of requirements gathering.
• JAD sessions replace the traditional way of
  conducting a series of interviews on a one-to-one
  basis with the users.
• Advantages Achieving consensus during the
  session when
• multiple sources of information exist, raising
  and
• addressing issues or assigning them for
  resolution, and
• immediately confirming information.

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JAD Session

• JAD sessions are used to scope the project. Each
  session should last two to three day. They are
  very focused and fast-paced.
• JAD sessions can be very formal and follow strict
  guidelines or be informal group sessions.

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JAD - Roles

• Whether they are formal or informal, there are
  four
• necessary roles to be filled
• Facilitator
• The Facilitator is the session leader. It is the
  facilitators
• responsibility to ensure that the objectives of
  the sessions
• are met.
• Scribes(s)
• Scribes are responsible for recording the minutes
  of the
• session and optionally constructing deliverables
  using an
• automated tool as the session progresses.

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JAD- Roles

• User
• The users provide knowledge specific to the scope
  of the
• project.
• Developers
• Developers are the team members who will be
  building
• the system.

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JAD Session

• The session is divided into three segments
• Introduction Welcoming remarks description of
  the facilities such as rest room locations,
  messages, reviewing the agenda and setting
  expectations.
• Conducting the session To confirm deliverables
  set out in the session objectives.
• Wrapping up the session By summarizing progress
  towards the objectives reviewing the agenda for
  the next one and obtaining feedback from the
  participants.

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JAD Session

• Potential drawbacks
• The commitment of a large block of time for all
  participants
• Requirements collected could be less than
  satisfactory due to unpredictability of the JAD
  session or organizational culture not
  sufficiently developed to enable the concerted
  efforts required to be productive in a JAD
  setting.

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Using Questionnaires
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Observing Decision-Maker Behavior and Office
Environment (Observing the Enterprise in
Operation)