Logical Data Modeling is one of the most widely used techniques to analyze and document business requirements. The Logical Data Model is a set of diagrams and supporting text containing the essential business elements, detailed definitions, and descriptions of the relationships between the data elements.
Assume you need to convince the project manager on one of your projects on which you are a lead developer, on the need for allocating time and resources for a thorough data modeling task on the project plan. What arguments would you put forth to support your case?
Below are points/arguments to support the case.
A logical data model is a graphical representation of the information requirements of a
business area - it is not a database.
A logical data model is independent of a physical, data storage device. This is the key concept of the logical data model. The reason that a logical data model must be independent of technology is simply because technology is changing so rapidly.
It is dangerous for application developers to continue to gather requirements with a specific
technology in mind. Our legacy problem continues to grow and multiply in complexity. We need to build systems that are as independent of technology as possible. Build a system that is independent of technology; isn't this an oxymoron? Yes and No. There are components of a system that are intimately linked to the technology: the programs, the database management systems, and the screen components. There are also components of the system that can be technology independent: the logical data model, the logical process model, the business rules. These components are intimately linked to the business, not the technology.
Most business areas do not change as rapidly as technology. Think of industries that have
been in business for 100 or 200 years. An insurance company provides coverage, receives
payments, and pays claims; and has done so for their entire history. They performed this
business without computers and now perform it on mainframes, minicomputers, PCs,
networks, and the Internet. What the business does, has not changed, but how the work
is accomplished, has changed significantly. This difference between WHAT the business
requirements are and HOW they are accomplished describes the ...
Logical data Modeling is explained.