You create task schedules to track resource scheduled hours, task hours to complete, or task and project percent complete. The act of creating a task schedule is referred to as "scheduling a resource to a task".
There are a couple of ways to create schedules.
1. Use the inline task scheduler in the task grid
2. Use the Scheduling Tab
3. Use the task Actions > Bulk Schedule Resources
These tools simplify the process of creating task schedules by supplying you with valid resource/role options.
Please note the following:
If you are using Project resource planning mode, the resources and roles presented to you in these tools are driven off the allocations you created in the Staffing screen. You have the option to find resources and assign roles outside of those allocations; allocations will be created automatically for those resources that do not already have allocations. Note that allocations cannot be created automatically for tasks with a duration greater than 10 years. You would have to create the allocation manually on the Staffing screen, and then create the schedule.
If you are using Task resource planning mode you typically have no allocations to start with. The Resource and Role lists presented in these tools are driven off of project Team members; you have the option of finding roles and resources outside of the team. After you create the schedule, a corresponding allocation is recorded on the Staffing screen (in read-only mode).