Information Technology Reference
In-Depth Information
Requirements Analysis Tools
A number of tools can be used to document requirements analysis, including CASE tools.
As requirements are developed and agreed on, entity-relationship diagrams, data-flow dia-
grams, screen and report layout forms, and other types of documentation are stored in the
CASE repository. These requirements might also be used later as a reference during the rest
of systems development or for a different systems development project.
Object-Oriented Systems Analysis
The object-oriented approach can also be used during systems analysis. Like traditional anal-
ysis, problems or potential opportunities are identified during object-oriented analysis.
Identifying key participants and collecting data is still performed. But instead of analyzing
the existing system using data-flow diagrams and flowcharts, an object-oriented approach
is used.
The section “Object-Oriented Systems Investigation” introduced a kayak rental example.
A more detailed analysis of that business reveals that there are two classes of kayaks: single
kayaks for one person and tandem kayaks that can accommodate two people. With the OO
approach, a class is used to describe different types of objects, such as single and tandem
kayaks. The classes of kayaks can be shown in a generalization/specialization hierarchy
diagram (see Figure 12.23). KayakItem is an object that will store the kayak identification
number (ID) and the date the kayak was purchased (datePurchased).
Figure 12.23
KayakItem
Generalization/Specialization
Hierarchy Diagram for Single
and Tandem Kayak Classes
ID
datePurchased
SingleKayak
TandemKayak
Of course, there could be subclasses of customers, life vests, paddles, and other items in
the system. For example, price discounts for kayak rentals could be given to seniors (people
over 65 years) and students. Thus, the Customer class could be divided into regular, senior,
and student customer subclasses.
The Systems Analysis Report
Systems analysis concludes with a formal systems analysis report. It should cover the following
elements:
•
The strengths and weaknesses of the existing system from a stakeholder's perspective
•
The user/stakeholder requirements for the new system (also called the
functional
requirements
)
•
The organizational requirements for the new system
•
A description of what the new information system should do to solve the problem
