Message Characteristics: Value Assignment in Planning 
Use
You assign characteristic values that are available during planning when you maintain the process instruction in Customizing, the master recipe, or process order.
When you maintain a process instruction in the PI sheet, the system automatically copies the message characteristics whose values have been assigned in planning to the process message.
Features
Basic Functions
You assign message characteristics whose values are assigned in planning directly to the process instruction.
When assigning the characteristic value, you have the following options:
You can enter the required value manually.
If the value has been entered elsewhere in the process order (for example, the phase or material number), it can be transferred to the process instruction by automatic value assignment when you create the control recipe. However, you can only use this option if the settings for automatic value assignment have been made for the message characteristic in Customizing: see Process Instructions: Automatic Characteristic Value Assignment .
See also:
Additional Functions
You cannot change characteristic values that have been assigned in planning in the PI sheet. However, you can display the characteristic value in the PI sheet if you also mark the characteristic as an output value; see Output Values .
If you want to use the characteristic value in one of the succeeding process instructions of the same process order, you can define a variable that refers to the message characteristic; see Definition of Variables .