Question

Entity-relationship data model (ERD)-Business rule, assumptions

You are required to develop an ER model to represent the information requirements of company you are working for.

You also need to write business rules and assumptions.

Task 2: Create the Data Dictionary base on your ERD diagram.

Answer 1

Entity relationship diagram is a high level diagram showing the data organization of a company or system;

Entity relationship diagram for a manufacturing company is as shown below;

Business rules and assumptions: These are the rules and constraints which is adaptem when the system works. Here, there are the company, suppliers, raw materials, product and invoice as entities.

Business rules and assumptions are as follows;

• The company makes many products.
• There are many raw material suppliers.
• A supplier will have only one invoice for a material.
• There are many types of raw materials.
• A produced product can have different grades.

Data dictionary is a written description of the entities and their operating procedure.

It is represented as below;

Entity Name	Entity Description	Attributes	Data Type	Length
Company	Company is the entity that produces the products.	Name	Characters	100
Product	These are the items that are being produced.	Quality	Characters	2
Product	These are the items that are being produced.	Batch	Numbers	10
Raw Material	Raw materials are the things being used for production.	Type	Characters	10
Raw Material	Raw materials are the things being used for production.	Grade	Characters	10
Supplier	Suppliers are entities who supplies the raw materials for production.	ID	Numbers	5
Supplier	Suppliers are entities who supplies the raw materials for production.	Name	Characters	20
Supplier	Suppliers are entities who supplies the raw materials for production.	Address	Characters	100
Invoice	Invoice is the request for payment that is submitted by supliers.	Invoice No.	Numbers	10
Invoice	Invoice is the request for payment that is submitted by supliers.	Date	Characters	10