You usually maintain data for external processing for activities outside of your organization. However, you can also enter data for the external processing in internal activities. For example, if you do not yet know whether the activity is to be processed internally or externally.

If you realize in the course of the project that an activity will be have to be performed externally to keep on schedule, then you only have to change the control key on the detail screen. The internal activity then automatically becomes an external activity. When you save the network, the system generates a purchase requisition for the external activity.

You can record the following data for external processing in the network profile:

• control key

• purchasing organization

• cost element

You enter the activity data on the External Processing Overview and on the detail screens.

If you maintain data for an external activity, you must also specify a cost element. The cost element determines how the external activity is to be valuated.

You can also define a work center for an activity performed externally. For example, if a vendor frequently performs the same activity for your company, and you have promised this vendor a certain quota of work. You can then track this vendor’s capacity in the Project System through the work center and by entering a control key in the external activity which allows capacity requirements planning.

If you change an external activity to an internal activity by changing the control key, this affects external processing as follows:

• If a purchase requisition has already been created for the activity, the requisition gets marked for deletion.

• If a purchase order already exists, you receive a warning. The purchase order is not deleted automatically.

You maintain the data for the purchase requisition on the External Processing Overview and the detail screen.

The purchasing info record is a source of information for the purchasing department. It contains quotation and purchase order data, which are copied into the purchase order.

When entering the data for an external activity, you do not have to reference an existing info record, rather you can also enter the data for the purchase requisition manually.

If you enter a purchasing info record, the following data is copied from and cannot be changed:

• sort string
• price unit
• price
• currency
• planned delivery time
• activity quantity
• material group