Representing Sequence Diagram for an ERP system

Question

I want to model sequence diagram for my ERP System that has twelve modules as follows:

CRM
HRM
SRM
Order Management
invoicing
reports generation
POS
accounts management
Inventory
Material management
Warranty claim

How to address/breakdown inter-module relationship and represent them in terms of sequence diagram?

Answer 1

Sequence diagram has a higher granularity than component or deployment diagram.

So if you want to represent your system in one single diagram, I would suggest going with a component diagram instead of the sequence diagram.

Sequence diagram represents communication flow between objects in terms of messages which are more granular compared to each module in your system.

Each module of your system will have multiple sequence diagram and representing entire system would be a too much complicated. UML diagrams are to represent the system in a most simpler way.

I hope this answers your question.

Thanks.