Project Structures
A structure in Oracle Projects is a hierarchical arrangement of tasks for use by a project. You can set up different structures in a project for different business purposes.

A project structure is often referred to as a work breakdown structure or WBS. You organize your project work into smaller, more easily manageable units called tasks. In each project structure, you can define an unlimited number of tasks, and as many levels of tasks as you want. You can number and name the tasks as you wish.

Task Position
Oracle Projects processes tasks based on their position in the structure. The three distinct positions are:

Top Task: A task whose parent is the project
Mid Task: A task that is not a top task or a lowest task
Lowest Task: A task that is at the bottom of the structure, without any child tasks

A top task can also be considered a lowest task, if the task does not have any child tasks. For example, in the following graphic, Tasks 1 and 3 are lowest tasks as well as top tasks. Tasks 2.1 and 2.3 are lowest tasks although they are on the same level as Task 2.2, which is a mid task. A task that is the child of another task is commonly referred to as a subtask.

Control Functions by Project and Task Level
The following tables show how Oracle Projects supports functions at the project and task levels: