This demonstration presents an interface for the seamless integration of business processes and production processes. Specifically, the interface defines the data to be exchanged between the execution engine of the Metasonic Suite and the communication standard OPC Unified Architecture (OPC UA) that is widely used in industrial process automation. This allows business processes to trigger and react to changes in physical processes, thus increasing the scope and the real-world awareness of BPM. The BPM conference participants will learn how to model and execute such real-world aware business processes based on examples from an ongoing EU research project. The target audience of this demo includes BPM researchers interested in approaches to seamless process management in production enterprises.
1.1
The benefits of business process management (BPM) have been recognized in many
domains. Most of the approaches and tools in BPM are sufficiently generic to be applied
to a large variety of domain-specific processes. One of the industries using BPM is
manufacturing. While in this industry business processes are certainly considered
important, they are not considered to be the core processes. It is the physical processing
and movement of materials on the shopfloor, with associated manual or automated
activities, that is the predominant concern of production managers and production
workers alike. On the other hand, most physical production processes need to be smoothly
embedded in the company’s business operations; for example, production cannot start
before raw materials are ordered and delivered, and products cannot be shipped before
their production is completed. Seamlessly integrating processes across business and
production is a major concern for next-generation manufacturing [
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The issue of seamless process management can be described using the IEC 62264
control hierarchy [
This paper presents an interface developed for the Metasonic BPM Suite that allows
exchanging data with PLCs via the OPC UA [
Fig. 1. Seamless process integration across the IEC 62262 control hierarchy (image on
lefthand side adapted from [
The features of the OPC UA interface have been derived from the structure of the
OPC UA standard [
The following features have been developed: (1) configure the endpoint of the server, (2) configure the relevant node (e.g. variable, method, and event), (3) read/write variables from/to business objects, (4) invoke methods on the server, and (5) subscribe to attributes or events provided by the server. Features 3, 4 and 5 are schematically described in Fig. 2 using the example of a “PLC subject” in the Metasonic Suite interacting with a PLC. Fig. 3 shows the user interface (called “refinement template” in the Metasonic Suite) for configuring a process step, using a lighting control process as an example. In the example, the activity “Switch Light On” is configured to set the value of a variable provided by an OPC UA server based on the value of a field in a business object. The usage is illustrated in Fig. 3 using three highlighted steps. Step 1 defines the dedicated OPC UA server endpoint. For a valid server URL the available nodes are displayed in a tree, from which the desired node can be selected (step 2). Finally, the field of the business object value to be written to the selected node is selected (step 3).
After modelling and configuring all subject behaviours, the process can be executed in Metasonic’s workflow engine. A screenshot of the user interface for executing the lighting control process is shown in Fig. 4.
1. Configure Endpoint 2. Configure Node 3. Configure Business Object value
The OPC UA interface is currently at the prototype stage. It is a result of ongoing research in the SO-PC-Pro project (Subject-Orientation for People-Centred Production). It has been tested within four application scenarios. In the first scenario, a process for managing sun-blinds in a smart home has been modelled and executed. In the second scenario, the prototype has been used to manage room lights in offices at different locations. In the third scenario, the power consumption of production machines in a medium-sized manufacturing company has been measured and analysed for process control and improvement. In the fourth scenario, an assembly process has been modelled in which the stress level of a worker (measured using a wearable sensor) is indicated by LED lights (green | yellow | red). A video showing the interoperation between the Metasonic Suite, a PLC for controlling the LEDs and a wearable sensor is available at: https://www.youtube.com/watch?v=uBi7Alv-dpE 3
The tool presented in this paper represents a new feature for Metasonic’s S-BPM modelling suite: an OPC UA interface for exchanging data between the workflow execution engine Metasonic Flow and PLCs. This feature allows modelling processes that span across all conceptual levels of production enterprises, making business processes able to respond to real-time events and trigger automated physical processes. Seamless process management capabilities are a key enabler of future production models such as internet-of-things (IoT) manufacturing.
Acknowledgements. The research leading to these results has received funding from the EU Seventh Framework Programme FP7-2013-NMP-ICT-FOF(RTD) under grant agreement n° 609190 (www.so-pc-pro.eu).