• By Jakob Dück

Interfaces are a vital component of modularization. But do machine builders have to adhere to specific standards?

One of the most significant challenges manufacturers face is: How do I serve the very special and unusual wishes of consumers? As things stand today, this would appear to apply only to makers of consumer packaged goods and other consumer products, such as automobiles and appliances. But the current trend toward factoring in individual customer wishes has consequences that extend deep into production technology choices. Original equipment manufacturers (OEMs) and their suppliers must consider the trend of mass customization.

The scope and degree of individualization as it is currently strived for can no longer be achieved with the tool kit of conventional mass production, but calls for a completely different design of production processes, including machines and systems. The individualization of mass production is one of the core aspects of Industry 4.0. The resulting challenge for the manufacturers of production systems is as follows: How should the necessary equipment and processes for “individualized production” be shaped and designed so that the costs will not explode and the resources required will not rise sky high?

KUKA, a robot manufacturer, has formulated an answer: “The key [to mass customization] lies in a high degree of standardization and automation, which at the same time affords scope for variations of customer-relevant product features. What is more, the concept of modularization, which provides customers specific, tailored product configurations based on a modular building block system, is a cost-effective way to meet individual customer needs.” This results in three central perspectives for OEMs:

  • the shift toward individualized serial customization
  • modularization as the key, in combination with automation and standardization
  • preservation of latitudes for the variation of customer-specific product features

This perfectly describes the conflicting demands made on OEMs in the mechanical and plant engineering sector. The dilemma is very reminiscent of the statement ascribed to the philosopher Hegel, “Freedom is the insight of necessity.”

Importance of interfaces

Interfaces are a vital component of modularization. But do they always have to adhere to certain standards? The increasing automation and modularization of production systems has technical and business advantages for both OEMs and end users. As the degree of automation rises and modularization deepens, however, it is precisely the interfaces that play an increasingly decisive role as the link between the elements or modules. This is because the following holds true: The interfaces do not determine the entire modularity, but, without interfaces, the modules will never become a whole.

This will be further differentiated, because in some instances standardized interfaces will be more advantageous and in others “individualized” interfaces will be more advantageous. The importance of customer-specific product definitions for OEMs in the mechanical and plant engineering sector can be well illustrated, as shown in the left side of the figure 1 diagram. The possible degree of product individualization by the end user is related to the life cycle of production systems. The further the cycle progresses, the smaller the remaining scope for individualization is (transition from “hard” to “soft customization”).

Figure 1. OEM individualization concepts according to time of customer integration (left side), and typical design for individualized interfaces according to functional groups (right side).

For OEMs to determine the right degree of individualization for their machines and to bring them into line with the different automation and modularization requirements along the life cycle, it is expedient to think in terms of different “clusters” or functional groups, such as sensor technology and drive technology.

Sensor and actuator technology. The development of electronic components has enabled a tremendous compression of functions. Higher energy efficiency and greater packing densities go hand in hand with these ongoing developments. The technology boost in this cluster is encountered in many places in the production system: in the process-integrated acquisition of input parameters and signals, in the on-site preprocessing of this input data, in the energy-efficient triggering and control of actuators, in brilliant image processing and reproduction, as well as in the touch functionalities of the operating units.

On one hand, this technological progress facilitates the decentralization, modularization, and scaling of machines. On the other hand, thinking in terms of ever more compact building blocks and elementary functions is becoming necessary, and the initial input and efforts required to develop such systems is on the rise.

Despite these partially negative implications, the advantages of customer-oriented individualization of the product range in mechanical engineering outweigh the disadvantages. This is because the appropriate overall arrangement of sensors, actuators, and other machine control components, as well as the interconnection of the functions and processes based on them, are absolute OEM domains. They alone hold comprehensive system competence here. These are the key assets they can leverage to their advantage.

Drive technology. There are similar significant and far-reaching shifts here. Although know-how was at the core of mechanical development in the past, in recent decades it has migrated almost entirely to software departments or electrical design. Due to the enormous increase in performance of the technologies for electronic drive controls, matched with decreasing prices at the same time, entirely new concepts for machine and production plants have emerged. The function group for the complex control of the motion sequences and related processes also forms a central competence of machine manufacturers.

Specialized technology units. It is noticeable that the manufacturers of manufacturing systems are increasingly concentrating on a few technologies in their development activities. The generalist perspective remains with the overall system suppliers, whose know-how resides precisely in the application and connection of technologies. With regard to the question of the right interfaces, however, it is the highly specialized technology units that are of interest. A common, defining aspect of these functional groups is the fact that they are deployed as finished units or aggregates with firmly circumscribed physical and technical functions and precisely defined interfaces. The linking of the units represents the central OEM know-how, not the components used themselves.

Some OEMs have deliberately opted for nonstandard interfaces on their technology units and machines. A control cabinet, for example, might require customer-specific interface solutions.

Digitalization. The term “digitalization” is omnipresent in today’s technical literature and other media and comprises many aspects. Applied to interfaces in mechanical engineering, it refers to data transmission technologies. Data transmission in the form of industrial bus systems—including Industrial Ethernet—has long been shaped and used by manufacturing technologists. The possibilities of cost-effective data connection to higher-level systems up to the cloud, with ever greater data throughput and real-time capabilities, are genuinely revolutionary in technology terms. These technologies would enable OEMs active in the mechanical and plant engineering sector to reshape their entire business approaches.

Different manifestations of these changes are described and designed under the heading of Industrial Internet of Things (IoT). All data transmission aspects, including industrial buses and industrial Ethernet, are considered here from the perspective of interfaces as a functional group or functional layer. While the solutions in this area are not part of the OEM’s core competence, they hold the greatest potential for change in today’s manufacturing systems. 

Deciding on individual interfaces

My company provides solutions for all electromechanical interfaces required in modern control, drive, human-machine interface, and communication technology for production systems at work in all branches of industry. Analyzing current customer applications, we have come up with the following advice for the individualization of interfaces based on the above-described function groups (right side of figure 1):

  1. Generally speaking, it makes sense to use individualized or customer-specific electromechanical interfaces for the functional groups, which largely represent the core OEM know-how.
  2. Customer-specific, tailored interfaces are most often used for those modules and aggregates that are developed or manufactured directly by the respective manufacturer. This applies to all degrees of product individualization in mechanical engineering, from “soft customization” through the various stages of “hard customization,” to one-of-a-kind productions.
  3. With regard to sensors and actuators, the typical interfaces for the respective industry sector are usually chosen. Trendsetters and innovators, however, do try to set themselves apart from the market by deploying specific, tailored interfaces.
  4. When it comes to data interfaces, machine manufacturers rely entirely on standardized solutions. This applies both to the industrial bus and Ethernet connections employed and to all other forms of digital data transmission.

What are the main reasons behind the design of the interfaces? In terms of data transmission, it is evident that both Industrial Ethernet and bus systems in the manufacturing area and the higher-level data interfaces are subject to tremendous change. The technologies deployed are largely determined by the suppliers of the control components. Therefore, the recommendations for production-system OEMs are twofold: 

  • As far as possible, these interfaces should follow the latest standards of the control technology employed and ensure the modularity and scalability of the machines and systems.
  • With regard to interfaces beyond the machine edge, such as those for connection to higher-level systems, the interfaces should always represent the advanced state of the art. 

Interfaces should follow the latest standards of the control technology employed and ensure the modularity and scalability of the machines and systems. These Har-motion connectors were developed to customer specifications.
Consequently, as an OEM, an economically and technically optimally designed system for current requirements is in place; it is a system that is at least in part capable of meeting future (yet unknown) requirements. Moreover, a company would then also be ideally equipped for the continuous expansion of after-sales and service activities based on digital services.

With regard to other functional groups, the advantages and disadvantages of individualized interfaces should be systematically weighed and listed individually. What are the arguments in favor of customized interfaces and what are the arguments against them? There are OEMs that have deliberately opted for nonstandard interfaces on their technology units, modules, and machines. Here are the key reasons:

  • End user requirements for companies that operate specific production lines and want to consciously differentiate themselves from individual suppliers or focus on them.
  • Differentiation vis-à-vis competitors in the expansion of business models to offer after-sales, service, and similar services aimed at a long overall life cycle of production systems. Individualized interfaces allow these services to be controlled and expanded in a user-friendly manner.
  • Intentionally nonstandard design of machine interfaces or equipping technology with specific interfaces in order to stand out from the competition. In particular, OEMs that perceive themselves as technology leaders, innovators, or trendsetters are taking advantage of these opportunities.
  • Use of sensors, actuators, or their combination developed according to specific specifications of individual manufacturers. In these instances, too, the protection of one’s own know-how is the strongest motive for leveraging individualized interfaces.

Customizing electromechanical interfaces to meet even the most unusual OEM requests is increasingly possible. Depending on the degree of individualization required, modular design principles applied to connector products can provide convenient scalability and minimal customization. At the highest level of “hard customization,” however, customer-specific interfaces can be developed to meet individual customer requirements. This range allows OEMs to cost effectively meet even the most unusual customer wishes in mechanical and plant engineering.

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About The Authors

Jakob Dück is global industry segment manager, mechanical engineering for HARTING Electric. After a control and measurement technology apprenticeship, Dück graduated with a diploma in electrical engineering from the Polytechnic State University in Odessa, Ukraine. He worked in R&D for an international machine manufacturer for more than 13 years before joining HARTING Technology Group in 2001.