090614 tb ddd and 591jj

After reading the service in "dddq", we found that its theory is consistent with the service when the 591jj architecture was designed (about 200808-200812! The explanation is a full explanation of the Service in 591jj!
The main content of dddq is the third chapter mdd. The knowledge it describes is similar to the ORM theory in peaa.

Therefore, if you want to learn the 591jj architecture, you can recommend that you read dddq and peaa first.
(Although I did not read "dddq" or "peaa" when I first designed the architecture, the idea is the same as theirs .)

Reflection: the existence of the service is only because this "responsibility" is required in the system ". OO has the "single responsibility" principle. We can also understand it as: Class/object if there is a responsibility. Therefore, this responsibility is the meaning of the service! Reference in dddq:
There are three characteristics of a service:
1. The operation performed med by the service refers to a domain concept which does not naturally belong to an entity or value object.
2. The operation performed med refers to other objects in the domain.
3. The operation is stateless.

Reference
Dddq: domain drive design quickly
Peaa: Patterns of enterprise application architecture