.
Data modeling
System Analysis
Entity- relationship diagram
DBMS
Agents
Event
Resource
Diagram Variation
Events
Resources
Agents
Attribute
One resource entity, one other event entity , and at least two participating agents
One event entity and at least two participating agents
Two event entities and at least one participating agent
Resource
Event
Agent
None
Customers
Invoices
Sales
Delivery trucks
1:1
1:N
M:N
0:N
Sales = 0 to many inventory and inventory equals one to many sales
Sale= 0 to many inventory and inventory equals 0 to many sales
Sale= 1 to many inventory and inventory equals 0 to many sales
Sale = o to many inventory and inventory equals 1 to many sales
System analysis and physical design
System analysis and conceptual design
Conceptual design and implementation and conversion
Phsical design and implementation and conversion
Every event must be linked to at least 2 agents
Every resource must be linked to at least two agents
Every agent must be linked to at least two events