By Nikolaus Fecht
The objective of smart factories is to achieve a high level of productivity and manufacture customized products quickly. However, there is more than one way of realizing this goal. The VDMA guideline "Industrie 4.0 meets Lean" shows how the two approaches complement each other and where there are contradictions between the two.
This guideline was drawn up in cooperation with TU Darmstadt and focuses on best-practice experiences from industrial applications. "Lean production and Industrie 4.0 have common goals," comments Prof. Joachim Metternich, Head of the Institute of Production Management, Technology and Machine Tools (PTW) at TU Darmstadt, adding: "After all, both are about time, quality and costs. Increasing flexibility and individuality are also important factors."
Lean 4.0 needs standardization
Prof. Metternich believes that lean production relies on a holistic process. Here, the focus lies on continuously improving processes, developing staff and eliminating waste on an ongoing basis. "This is where Industrie 4.0, in which the product seeks its own way through the factory, suddenly comes into play," he explains. "If one takes Industrie 4.0 in a literal sense, it contradicts the lean principle in which the first priority is to standardize processes and recognize deviations," states Metternich. In his view, Industrie 4.0 differs in that it requires no fixed standardization of processes on the basis of speed, sequence or fixed inventories. Continuous improvement is also unnecessary, as the process optimizes itself autonomously.
The VDMA working group "Industrie 4.0 meets Lean", founded in February 2017 takes a pragmatic approach to tackling this dilemma together with the PTW. "We do see the potential for conflict," says Metternich, continuing: "But we ask where Industrie 4.0 and digitalization can help us in order to improve within the scope of the lean philosophy."
While working on the guideline, the PTW researchers and the participating companies made the following findings:
- Lean is still the leading approach.
- Digital upgrading is attractive and makes economic sense.
- With Industrie 4.0, information gains a new value within the lean system.
The researchers are certain that the classic model of thinking in accordance with the principle of "plan, do, check and act" (PDCA) will not be abandoned. Rather, digitalization serves to enhance this cycle. "In the future, processes will be standardized as needed. We will be able to visualize processes better, identify problems more quickly and provide employees with optimal support at their workplaces," explains Metternich. Information will then be given much more attention, as it will no longer be seen only through the lens of the production employee, as is usually the case with value stream mapping. "We will no longer think about waste from a management perspective, but also with regard to how information is handled," adds the researcher.
Production is not the sole focus
Metternich believes that taking a holistic view means significantly broadening your horizon to include aspects that concern order processing. He names Trumpf GmbH + Co. KG in Ditzingen as a positive example in this regard. Its customers use a configuration tool on the internet to put together a punching device in the morning, and might even receive the finished article the same evening. This is consistent with a PTW analysis showing that the actual production process only makes up a small part of the lead time in the overall value stream process. "We spend 67 percent of the time on development and procurement. Clarification of the order takes up 29 percent of the time, with the actual production only accounting for 4 percent," explains Metternich, who continues: "This demonstrates that lean still needs to change significantly when it comes to the value stream mindset."
Atlanta Antriebssysteme E. Seidenspinner GmbH & Co. KG from Bietigheim-Bissingen entered the lightweight robots sector in 2017 and aims to develop system solutions together with an Asian robot manufacturer. "We want to work more as a system integrator in the future," says Managing Director Joachim Schneider. "However, it is only possible for a company to offer such system solutions affordably and compete with large corporations if it has done its homework in its own production."
Establishing Industrie 4.0 among employees
Here, the company relies on the ingenious interplay of the theory of constraints (TOC), which comprises technology, cost considerations and bottleneck management, as well as on lean production and digitalization. "As an advocate of TOC and lean, I contributed these topics when working on the ‘Industrie 4.0 meets Lean’ guideline," emphasizes Schneider. This is where the experiences come into play, which Atlanta has anchored in the introduction of TOC and lean concepts, not only in the organization itself, but primarily among employees. "For me it means that everyone in the department must be able to do everything," explains the Managing Director, adding: "This is my approach when it comes to increasing flexibility." In his view, Industrie 4.0 serves as a tool that helps combine information and communication. He sees the introduction of TOC as a common thread in this.
Making processes transparent
Joachim Schneider specifies processes and people as the two decisive factors. It is thus important to digitalize processes and make them transparent. He also believes it is essential to make communication and the lean principle visible and tangible using Industrie 4.0. "Everyone at our company can note their thoughts and concerns on a failure report card; a process we are currently digitalizing," reports Schneider. Furthermore, the products are given a matrix code, with which Atlanta and its customers can access all relevant information on a component using an app. Based on this information, customers can use the code to order a product with the same version and with the same functions as components that are already in use.
Schneider aims to implement the first lean Industrie 4.0 concept by the end of 2019. "The solution will be perfect in my eyes when it allows us to cover the complete value chain digitally, all the way up to the customer," says Schneider. "Communication should then work flexibly in both directions."
More efficient maintenance
Festo AG's new Technology Plant in Ostfildern-Scharnhausen is leading the way when it comes to Industrie 4.0. Here, maintenance and IT staff have developed an app that greatly simplifies maintenance processes and enhances their efficiency. Every maintenance employee is provided with a tablet and is directly connected to the central SAP maintenance system via the app. The app paid for itself in just a few months. Every year, it saves Festo 3,500 man and machine hours arising from around 19,000 error messages and 2,000 planned maintenance orders.
"Previously, the maintenance staff checked the orders in the SAP system every morning and cycled to the deployment location, only to go back again due to a lack of information or parts," remembers Marius Christian, Portfolio Manager at Festo Didactic SE from Denkendorf. "The construction of the new Scharnhausen Technology Plant provided the incentive to create an app with a direct connection to the maintenance interface of the SAP system. As such, all documentation can now be accessed on the go." Traveling is therefore no longer required and the maintenance staff can concentrate better on their actual work.
The system has enjoyed a positive reception among maintenance staff and operatives. "The maintenance employees defined what they need for their work during a workshop," reports Christian. Using this information, the company made its processes lean and then digitalized them in the next step. Alongside an employee survey, Christian also recommends thinking outside the box and considering a license model with an external partner during realization. "This way, the employees benefit from the expertise of specialists from various fields while calculation security for amortization is also assured."
All the important key performance indicators at a glance
The solution is a well-balanced combination of lean production and Industrie 4.0 which also takes production employees into consideration. "For instance, the operator of a machine tool needs to empty the shavings container once daily and check the fill level of the cooling lubricant once a week," reports Christian, continuing: "For this independent, planned maintenance, employees have an app with which they enter the operations in question." Festo also offers this app to customers through an app store. The maintenance staff, on the other hand, work with the Mobile Maintenance App when processing faults and larger planned maintenance measures, such as annual inspections.
Christian believes that the ability to view and change documentation and information in the SAP system via a tablet is an important element of a lean solution, which helps prevent time and money from being wasted. Moreover, it makes it easier to record machine and working times while also realizing consistent documentation.
Improved data quality
The digital entry of confirmation data also reduces the number of data interfaces and improves data quality. According to Marius Christian, better data quality allows the evaluation of typical key performance indicators for maintenance such as mean time to repair (MTTR). The Scharnhausen Technology Plant is among the showcase factories in terms of Industrie 4.0, not least thanks to innovations such as the maintenance app. But there is still a long way to go before the production processes of all the company's plants have been fully digitalized.
Munsch Chemie-Pumpen GmbH from Ransbach-Baumbach was faced with an entirely different problem. "When the variance of our products exploded due to our realignment following the financial crisis, our kanban cycles no longer worked," comments Managing Director Stefan Munsch, who continues: "We need to produce synchronously and in an order-related manner from the very beginning, as the variance begins as soon as the raw parts are manufactured. Now we have redefined the process chains and the implementation of Lean 4.0 should be complete by 2022."
Digitalization: "clean" standardization
The company tackled the issue of digitalization together with the "Mittelstand 4.0" competence center of TU Darmstadt. The project partners looked at drilling locations that the employees often transferred incorrectly from the drawing to the CNC program. For this reason, installers were unable to fit pumps, motors and accessories on the base plate as planned in the product configurator due to boreholes being in the wrong position. An analysis of the drilling patterns for the pump base plates indicated a programming error. Munsch then worked together with the Darmstadt experts to eliminate the error by standardizing and digitalizing all involved processes as well as CNC programming. "In this small Industrie 4.0 project we learned that digitalization promotes and expands the lean principle," says Munsch, emphasizing: "However, we also realized that the goal of digitalization can only be achieved with very clean standardization and data processing."
Number of CNC programs reduced
In a follow-up project, developers in design have started working with variables to which they only assign fixed values during product configuration. "In one machine alone we were able to lower the number of CNC programs from around 1,700 to 20," explains Munsch. Workers at the site can now improve the program and the associated subprograms. According to Munsch, this is the advantage when developers no longer focus on completely finished parts, but instead think of solutions.
Recently, digitalization has also optimized the work of a subsidiary for plastic welding technology, which repairs devices. "The customer can register the repair job on the internet," says Munsch, praising the process.
The Managing Director has drawn his own conclusions from the projects: "Digitalization does not make bad processes better. A company should start with classic value stream mapping and only tackle digitalization on a step-by-step basis once the processes have been simplified in a clear and clean fashion," he explains. "In my opinion, the recipe for success is making processes transparent and simplifying them with a direct view to the value stream and digitalization," concludes Munsch.
Communicating according to the traffic light principle
At technotrans AG from Sassenberg, new products require faster and less complicated communication between the various business units. The objective was to devise a program that provides information on open questions via PC terminals in production. A traffic light principle in which the level of urgency is signalized by color was planned. Requests marked red are to be resolved in 15 minutes, and those in yellow within 45 minutes. Green indicates that everything is OK.
The department in question is addressed directly through pop-up windows. When an employee clicks on a pop-up window, he or she takes on the task and the window disappears from all other computers. A large central monitor informs all colleagues of the traffic light status of each individual workplace. A multicolored LED light above the respective production line shows the current status of that line.
"When we were on the lookout for a cost-effective implementation, we stumbled upon the potential of employees, many of whom use the Raspberry Pi minicomputer privately for 35 euros," explains Operations Manager Norbert Dunker: "For the IT employees, a hobby thus became a successful work project. We were able to implement the project quickly, as our employees were prepared to support their employer with
skills we previously didn't know they possessed." For him, this project is a good example of how a Lean 4.0 solution can be implemented. Therefore, companies should explain the project to their employees prior to realization. "Then they will make all their knowledge available, even knowledge they otherwise only use privately," stresses Dunker.
Lean and digitalized in two years
Dunker sees it as positive that a lean Industrie 4.0 solution based on just one front-end program came into being in this manner. "We should achieve the objective of a lean Industrie 4.0 solution in production in a maximum of two years in the case of old designs that need to be revised. We will bring new devices or components up to date straight away by training manufacturing staff," he comments with a smile.
VDMA Forum Industrie 4.0 | VDMA Business Advisory | Atlanta Antriebssysteme E. Seidenspinner | Festo Didactic | Munsch Chemie-Pumpen | Institute of Production Management, Technology and Machine Tools (PTW), TU Darmstadt | technotrans