Let's look at an example of a minimal implementation approach to the integration of SAP Digital Manufacturing and the shop floor, and explore what would be needed to run this integration scenario.
For this minimum implementation approach, only one data tag is integrated: PartCount. The PartCount data tag (indicator) is a counter on the machine layer that counts when the production of a part is finished. This information is then sent to SAP Digital Manufacturing, where a production process is triggered. A lot of data can be derived from this single data tag. For example, the PartCount not only counts the manufactured parts, it also indicates whether the machine is running, because if the part count is not increasing over time, you can derive that the machine is not running. Thinking this way often helps to solve issues with machine integration problems, especially if particular data tags are not available on the PLC layer.
In the example, only a PartCount data tag is integrated from the shop floor to SAP Digital Manufacturing. The initial start of each production order (the first SFC of each order) is manually started from SAP Digital Manufacturing by the operator. When the machine finishes the first SFC, the PartCount data tag increases. From this point onwards, an automatic trigger is used that reacts on each PartCount increase and triggers a production process.
The input for the production process is the plant, resource, and operation (in this simplified scenario, all values are hard coded as they are always the same) and, with this input, the API for the Retrieve Order Work List is called. The response of the API shows which SFC is in progress. The specific SFC will be completed by calling the Complete API. After this, the Start API will be called for any other SFCs in the queue for this production order. These steps are repeated until all SFCs in the production order are completed.
This means that all of the required logic was created in SAP Digital Manufacturing with only one integrated data tag. Of course, this scenario only works if one SFC of the production order already has a status of Active, as the SFCs are selected by status. However, if this can be ensured, the use case can be quickly and easily set up.
