Maintenance services may be classified into below categories:
1) Support Services
2) Production Environment Support Services
3) Application Maintenance & Enhancement
4) System enhancement services
5) Database Management
6) Hardware support services.
The primary purpose of support service is to ensure the availability of the application and its data for its users at any given time, even in cases of planned or unplanned system failures. The support provided may be proactive (for example: providing a systematic plan of preventive maintenance) or reactive (responding to user-end issues as and when they occur).