You can use transaction controls to configure your projects and tasks to allow only charges that you expect or plan. You can define what items are billable and non-billable on your contract projects. You can define what items are capitalizable and non-capitalizable on your capital projects.
You can configure transaction controls by the following:
Expenditure Category
Expenditure Type
Non-Labor Resource
Employee
Scheduled Expenditure Only
Workplan Resources Only
Person Type
Other Sources
Budget Setup: Resources and Resource Lists, Oracle Projects Implementation Guide
Transaction Control Extensions, Oracle Projects APIs, Client Extensions, and Open Interfaces Reference