Database Reference
In-Depth Information
Scope and direction determined . We can capture extremely complex and encom-
passing application requirements on a single piece of paper. After capturing such
a broad perspective, we can more easily identify a subset of the model to analyze.
For example, we can model the entire Logistics department and then scope out of
this a particular logistics application that we would like to build. The broad per-
spective of conceptual data modeling can help us determine how planned and ex-
isting applications will coexist. It can provide direction and guidance on what new
functionality the business will need next.
Proactive analysis performed . By developing a high-level understanding of the
application, there is a strong chance we will be able to identify important issues
or concerns proactively, saving substantial time and money later on. Examples in-
clude term definition differences and different interpretations of project scope. I
once worked on a project with a university, and we didn't realize the term Student
had multiple conflicting definitions until we started conceptual data modeling!
Key terms defined . The conceptual data model contains the most important con-
cepts of the project and requires that each of these concepts be defined and docu-
mented. Clear and complete definitions at this level are essential for effective com-
munication across the project team. When well-defined terms are mentioned dur-
ing meetings or in project documentation, people will be clear on what these terms
mean or have the ability to find out because these terms are documented, ideally in
an accessible and user-friendly format such as a wiki.
C ONCEPTUAL D ATA M ODELING A PPROACH
Conceptual data modeling is the process of capturing the satellite view of the business re-
quirements. There are five steps to conceptual data modeling, as illustrated in the diagram
on the next page. Before you begin any project, there are five strategic questions that must
be asked (Step 1). These questions are a prerequisite to the success of any application ef-
fort. Next, identify all of the concepts within the scope of the application you are building
(Step 2). Make sure each concept is clearly and completely defined. Then determine how
these concepts are related to each other (Step 3). Often, you will need to go back to Step 2
at this point because in capturing relationships you often come up with new concepts—and
then there are new relationships between these concepts. Next, decide the most useful form
for making sure your work during this phase is put to good use (Step 4). Someone will need
to review your work and use your findings during development, so deciding on the most
useful form is an important step. As a final step, review your work to get approval to move
on to the logical data modeling phase (Step 5).
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