I am currently in the middle of development of a service management application. These are some of the requirements I started with:

Dashboard
- display your schedule;
- display jobs and tasks assigned to you;
- news feed – this can include any notices, overdue tasks/jobs, internal messages, etc.

My Profile
- view/edit my profile details
- change password

Clients
- search/browse all clients
- view client details
- create new client

Jobs (Design/Service/Sales/Support)
- search/browse all the jobs
- view job details
- create new job

Quotes
- search/browse all quotes
- view quote details
- create new quote

Invoices
- search/browse all invoices
- view invoice details
- pay & close invoice
- create new invoice

Reports
- Time-sheets
- Client Reports
- Job Reports
- Invoice Reports
- Custom Reports

Accounts
- search/browse all user accounts
- view account details
- create an account

Settings
- Account settings
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Help
- Documentation & User Guide