Logical database design with the entity-relationship model

Before you implement a database, you should plan or design the database so that it satisfies all requirements.

Designing and implementing a successful database, one that satisfies the needs of an organization, requires a logical data model. Logical data modeling is the process of documenting the comprehensive business information requirements in an accurate and consistent format. Analysts who do data modeling define the data items and the business rules that affect those data items. The process of data modeling acknowledges that business data is a vital asset that the organization needs to understand and carefully manage. This section contains information that was adapted from Handbook of Relational Database Design.

Consider the following business facts that a manufacturing company needs to represent in its data model:

• Customers purchase products
• Products consist of parts
• Suppliers manufacture parts
• Warehouses store parts
• Transportation vehicles move the parts from suppliers to warehouses and then to manufacturers

These are all business facts that a manufacturing company's logical data model needs to include. Many people inside and outside the company rely on information that is based on these facts. Many reports include data about these facts.

Any business, not just manufacturing companies, can benefit from the task of data modeling. Database systems that supply information to decision makers, customers, suppliers, and others are more successful if their foundation is a sound data model.