Analysis - Data Modelling

Question 1

How does a data model develop over time?

Answer 1

• The data model is drawn by an iterative process in which the model becomes more detailed and less conceptual over time.

Question 1

What is a data model?

Answer 1

• A data model is a formal way of representing the data that are used and created by a business system; it illustrates people, places, or things about which information is captured and how they are related to each other.

Question 2

How is a data model used in the analysis phase?

Answer 2

• During analysis, analysts draw a logical data model, which shows the logical organization of data without indicating how data are stored, created, or manipulated

Question 3

How is a data model used in the design phase?

Answer 3

• In the design phase, analysts draw a physical data model to reflect how the data will physically be stored in a databases and files.

Question 4

How is a data model used in the design phase later on?

Answer 4

• Later, during the design phase, the data model is changed to reflect exactly how the data will be stored in databases and files.

Question 5

What does ERD stand for?

Answer 5

Entity relationship diagram

Question 6

What is an entity relationship diagram?

Answer 6

• An entity relationship diagram (ERD) is a picture which shows the information that is created, stored, and used by a business system.
• On an ERD, similar kinds of information are listed together and placed inside boxes called entities.
• Lines are drawn between entities to represent relationships among the data
• Special symbols are added to the diagram to communicate high-level business rules that need to be supported by the system.
• The ERD implies no order, although entities that are related to each other are usually placed close together.

Question 7

How can an analyst use an entity relationship diagram?

Answer 7

An analyst can read an ERD to discover the individual pieces of information in a system and how they are organized and related to each other.