You can set up activities when you want to assign a task to a salesperson that is complex and could be divided into several steps. The to-dos composing the activity are linked to each other by a date formula.
Open the 
Activity window.
Press F3 to enter a new activity.
On the header, fill in the Code and Description fields.
Click the first empty line to enter the first to-do within the activity.
In the Type field, click the
AssistButton 
and choose one of the three
options: Blank, Meeting, and Phone Call.
Fill in the Priority and Date Formula fields for this line. For Help about a specific field, click the field and press F1.
Repeat steps 4 to 6 to enter all the to-dos within the activity.
When you assign an activity to a salesperson, the program simultaneously assigns all the to-dos within the activity and uses the current program date to calculate the date on which the to-dos are due.