Process instructions consist of the following elements:

• A header

• Characteristics

• Characteristic values

The header of a process instruction contains general information on the process instruction such as the instruction type and category.

In process instructions, characteristics can have two functions. They can be used to specify:

• The type of information conveyed or requested,
  for example, "process order number", "control recipe status" or "control instruction"

• How the requested data should be processed,
  for example, that a specific value should be provided by process control or which message category should be used to report this value

Process instruction characteristics are defined and assigned to the instruction category in Customizing. In the instruction category, you also specify a sequence for the characteristics.

When you create a process instruction in a master recipe or a process order, the characteristics assigned to the respective instruction category are copied into the process instruction. Within the process instruction, you can assign further characteristics or delete existing assignments.

There are no restrictions as to the number of characteristics that can be assigned to a process instruction. A characteristic can be assigned more than once to the same process instruction.

Characteristic values can be assigned to process instruction characteristics in the instruction category or in a specific instruction in the master recipe or process order:

• Values providing general information such as the category of the message to be sent are assigned to the instruction category. They are copied when an instruction is created in the recipe.

• Process-specific values, such as the material quantity required for the process or a specific validation rule, are assigned to the instruction in the recipe.

• Values specific to the individual production run, such as the name of the device from which a measured value is to be obtained, are assigned in the process order.

A process instruction is only complete after a value has been assigned to each characteristic. The format of the values as well as the value range to which they must belong is defined in the characteristic in Customizing.

The value of an instruction characteristic can be a numeric or alphanumeric key, a short text or a long text or the name of a message characteristic which is to be processed in a specific way.

If a corresponding function module or table field has been assigned to a characteristic in Customizing, the value of this process instruction characteristic can be assigned automatically in the process order or when you create a control recipe.