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Chapter 11

Database Analysis and the

DreamHome Case Study

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Chapter 11 - Objectives

When fact-finding techniques are used in the database application lifecycle.

The types of facts collected in each stage of the database application lifecycle.

The types of documentation produced in each stage of the database application lifecycle.

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Chapter 11 - Objectives

The most commonly used fact-finding techniques.

How to use each fact-finding technique and the advantages and disadvantages of each.

About a property rental company called DreamHome.

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Chapter 11 - Objectives

How to apply fact-finding techniques to the early stages of the database application lifecycle.

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Fact-finding techniques

It is critical to capture the necessary facts to build the required database application.

These facts are captured using fact-finding techniques.

The formal process of using techniques such as interviews and questionnaires to collect facts about systems, requirements, and preferences.

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When Are Fact-Finding Techniques Used?

Fact-finding used throughout the database application lifecycle.

Crucial to the early stages including database planning, system definition, and requirements collection and analysis stages.

Also used during database design and the later stages of the lifecycle (lesser extent)

Enables developer to learn about the terminology, problems, opportunities, constraints, requirements, and priorities of the organization and the users of the system.

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Examples of data captured and documentation produced during the database application lifecycle

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Fact-Finding Techniques

A database developer normally uses several fact-finding techniques during a single database project including: – examining documentation– interviewing– observing the organization in operation– research– questionnaires

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Fact-Finding Techniques: Examining documentation

Can be useful – to gain some insight as to how the need for a

database arose. – to identify the part of the organization

associated with the problem. – To understand the current system.– Documents, forms, reports, files

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Examples of types of documentation that should be examined

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Fact-Finding Techniques: Interviewing

Most commonly used, and normally most useful, fact-finding technique.

Enables collection of information from individuals face-to-face.

Objectives include finding out facts, verifying facts, clarifying facts, generating enthusiasm, getting the end-user involved, identifying requirements, and gathering ideas and opinions.

Require good communication skills for dealing with people

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Advantages and disadvantages of interviewing

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Interviewing

There are two types of interviews:

– Unstructured» General objective in mind and with few specific questions» Rely on the interviewee to provide framework and

direction to the interview

– Structured » Interviewer has a specific set of questions to ask.» Additional questions for clarification or expansion

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Interviewing

Open-ended questions allow the interviewee to respond in any way that seems appropriate.– “why are you dissatisfied with the report on

client registration?” Closed-ended questions restrict answers to

either specific choices or short, direct responses. – “are you receiving the report on client

registration on time?” Yes or No

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Fact-Finding Techniques: Observing the Organization in Operation

An effective technique for understanding a system.

Possible to either participate in, or watch, a person perform activities to learn about the system.

Useful when validity of data collected is in question or when the complexity of certain aspects of the system prevents a clear explanation by the end-users.

Successful observation requires preparation

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Advantages and disadvantages of using observation

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Fact-Finding Techniques: Research

Useful to research the application and problem.

Use computer trade journals, reference books, and the Internet (including user groups and bulletin boards).

Provide information on how others have solved similar problems, plus whether or not software packages exist to solve or even partially solve the problem.

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Advantages and disadvantages of using research

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Fact-Finding Techniques: Questionnaires

Conduct surveys through questionnaires, which are special-purpose documents that allow facts to be gathered from a large number of people while maintaining some control over their responses.

There are two types of questions:– free-format – fixed-format

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Fact-Finding Techniques: Questionnaires

Free-format – Offer the respondent freedom in providing answer

– “Are there any problems with these reports?”

– Difficult to tabulate respondent’s answers

Fixed-format :-– Require specific responses (Yes or No, strongly

agree, disagree, no opinion, etc)

– Easier to tabulate result

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Advantages and disadvantages of using questionnaires

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Using Fact-Finding Techniques – A Worked Example

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Using Fact-Finding Techniques – A Worked Example

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Using Fact-Finding Techniques – A Worked Example

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Using Fact-Finding Techniques – A Worked Example

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Using Fact-Finding Techniques – A Worked Example

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Using Fact-Finding Techniques – A Worked Example

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Using Fact-Finding Techniques – A Worked Example

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Mission Statement for DreamHome Database System

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Derived by conducting interviews with the top management of the organization.Eg. of interview questions:-1.What is the purpose of your organization?2.Why do you feel that you need a database?3.How do you know that a database will solve your problem?

Database Planning

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Mission Objectives for DreamHome Database System

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What is your job description? What kinds of tasks do you perform in a typical day? What kinds of data do you work with? What types of reports do you use? What types of things do you need to keep track of? What service does your company provide to your

customers?

Database Planning

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Mission Objectives for DreamHome Database System

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Database Planning

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System Boundary for DreamHome Database System

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Major User Views for DreamHome Database System

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System definition

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Gathering information on the user views

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What type of data do you need to hold on staff? What sort s of things do you do with the data on staff?

Requirements Collection & Analysis

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Gathering information on the system requirements

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What transactions run frequently on the database? What transactions are critical to the operation of the

organization? When do the critical transactions run? When are the low, normal and high workload periods for

the critical transactions? What type of security do you want for the database system? Is there any highly sensitive data that should be accessed

only by certain members of staff?

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Gathering information on the system requirements

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What historical data do you want to hold? What are the networking and shared access

requirements for the database system? What type of protection from failures or data loss do

you want for the database system?

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Cross-reference of user views with main types of data used by each

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Collection & Analysis

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System specification

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Types of features that should be described:– Initial database size– Database rate of growth– Types and average number of record searches– Networking and shared access requirements– Performance– Security– Back up and recovery– Legal issues

Requirements Collection & Analysis