Database Reference
In-Depth Information
is referred to as
requirements analysis
, and involves a range of activities that eventually
lead to the deliverable we call the
requirements specification
(RS). In particular, the
software engineer must determine the following:
•
Synergistic interrelationships
of the system components: This
relates to the components and how they (should) fit together.
•
System information entities
(
object types
) and their
interrelatedness: An entity refers to an object or concept about
data is to be stored and managed.
•
System operations
and their interrelatedness: Operations are
programmed instructions that enable the requirements of the
system to be met. Some operations are system-based and may be
oblivious to the end user; others facilitate user interaction with
the software; others are internal and often operate in a manner
that is transparent to the end user.
•
System business rules:
Business rules are guidelines that specify
how the system should operate. These relate to data access, data
flow, relationships among entities, and the behavior of system
operations.
•
System security mechanism(s)
that must be in place: It will be
necessary to allow authorized users to access the system while
denying access to unauthorized users. Additionally, the privileges
of authorized users may be further constrained to ensure that they
have access only to resources that they need. These measures
protect the integrity and reliability of the system.
As the software engineer embarks on the path towards preparation of the
requirements specification, these objectives must be constantly borne in mind. In the
early stages of the research, the following questions should yield useful pointers:
•
WHAT are the (major) categories of information handled? Further
probing will be necessary, but you should continue your pursuit
until this question is satisfactorily answered.
•
WHERE does this information come from? Does it come from an
internal department or from an external organization?
•
WHERE does this information go after leaving this office? Does it
go to an internal department or to an external organization?
•
HOW and in WHAT way is this information used? Obtaining
answers to these questions will help you to identify business rules
and operations.
•
WHAT are the main activities of this unit? A unit may be a division
or department or section of the organization. Obtaining the
answer to this question will also help you to gain further insights
into the operations.
