Spread Curve (Tools Tab)
Spread curves allow you to define the manner in which a resource assignment is distributed over the duration of an activity.
When assigning a resource to an activity, you can use the Res. Curve field on the Resources tab of the Activity Details dialog box to select a predefined spread curve.
Clicking Spread Curves on the Tools tab displays the Spread Curves dialog box, which displays a list of spread curves that you can use when assigning resources to an activity.