The ability to manufacture products according to variable lot size without substantially increasing production costs is an indicator of the Smart Factory. The future success of production facilities will largely be determined by their capacity for production changeability and the ability to network to a high degree along the entire value chain—up to the final product.
In production, this all depends on the existing conditions at each location. Because of this, the Smart Factory cannot simply be seen as a bolt-on solution but as being integrated as a smart version of an existing production line, with the added benefits of being as individual and as application-specific as the processes of the company itself.
There must also be consideration given as to which ideas, methods or approaches could lead to an improvement in the existing individual production processes. These improvements may lie in the more efficient use of resources during production, preventing duplication of applications along the value-added chain or significantly shortening system-engineering times.
No matter which method is applied for transitioning from the existing original to the Smart Factory, networking of extant processes and operations remains a pre-requisite. This networking includes the vertical—from the control system to the field level, as well as the horizontal—which extends beyond the various steps in the value-added chain.
The only opposition to this type of complete networking is that the data cannot be consistently generated and used. Diverse media and system discontinuities, which occur at both levels, but primarily in horizontal integration, introduce difficulties in correlating data logically and sensibly across unique processes.
As a rule, each IIoT (Industrial Internet of Things) approach consists of recording, digitizing and linking data to one another in a profitable way. This step is precisely the central thought that drives IIoT—collecting, networking and evaluating data from the production process to exploit that data profitably such that a sustainable added value is generated for the corporation.
Data transparency for the smart factory
The first step along this path is transparency across all production and system data. Only when the data is brought into context with one another, suitably processed and consolidated into information can measures be introduced to improve the production process. For this to succeed, sensors must record product and production-relevant data at the field level. These sensors must be considered in the system architecture or incorporated into the product itself.
Regarding production-relevant data, which is recorded via sensors on the machines and systems, the challenge consists less in the mere collection of data, but instead in bringing information securely and error-free from the field level to a higher level—for example, a manufacturing execution system (MES) or the cloud. With the relatively high expense of transferring and storing data in the cloud, it does not make sense to have raw sensor data sent directly to higher level systems.
Automation edge controllers can provide a decisive contribution. Modular systems can offer a suitable solution for practically any sensor interface. Thus, signals can always be reliably collected from the field level and managed locally on the plant floor. Edge controllers with different communication interfaces and fieldbuses can be used to collect this data horizontally from devices independent of manufacturer via CANopen, Profibus DP, EtherNet/IP or Modbus-TCP and can also manage the vertical information via MQTT and OPC UA protocols.
Some advanced edge controllers can be incorporated into already existing automation systems as scalable nodes and gateways, which can be retrofitted without having to interfere with the actual automation process. The data can then be aggregated into abridged information that is transmitted to a higher level, such as an MES or the cloud. In this framework, the advantages connected with a cloud link initially appear quite promising, as cloud solutions are flexible, scalable, highly available and provide the opportunity for centralized access.