How to design a large Risk Control System with Java projects

I am building a risk control system for online payment. As a complicated system, it should have some sub projects:

1. An admin web interface;
2. An rpc service api for other services;
3. A data sync system for syncing business data to risk control system DB;
4. A data processing and merging system for process data in DB to useful values in Redis;
5. A risk rule engine service to combine data by rules;
6. A data access service for all the system above to write and read DB or Redis.

I am trying to build a maven project and treat the systems above as modules, but I think it is still too large. Could I split them to different projects? Is there some weak points?

Another question, I'm going to build a data access service, and other systems will use this service when they want to operate with Database or Redis. Is it good for my system? May I create a standalone service or just a maven dependence?

Somebody give me some advices?