From Simulation Technology to the Digital Factory
Everywhere in industry, planners and investors are knitting away at concepts for the “digital factory”. The major automotive manufacturers are leading the way. The tools of digital manufacturing, and here above all simulation technology, enable companies today to virtually represent complex production and logistics landscapes! The basis for this is primarily the data material from ERP, PDM, EDM and CAD systems.
Manufacturing companies are facing enormous challenges at the beginning of the 21st century: On the one hand, the rapid development of information and communications technology offers unimagined opportunities to develop, produce and launch innovative, high-quality products much faster than before. On the other hand, however, investment risks are rising rapidly in an increasingly global and dynamic competitive environment. In order to make these risks manageable and increase planning security, industry is currently working at full speed on viable concepts for the digital factory. In many cases, they are drawing on the experience of innovative service companies such as SimPlan AG, Maintal.
It is true that the digital or virtual factory – i.e. the true-to-life, integrated computer model of a production system down to the individual development and processing step – is still a vision in many cases. But leading global companies in the automotive and aerospace industries are making giant strides toward this goal. All participants, including small and medium-sized partners in value chains, must actively engage in this development process if they are to compete successfully.
The digital factory maps all logistics and production processes that characterize a (later) real factory. It therefore reflects the actual production processes at all times – even while the real factory has long been running. Therefore, anyone who has the digital factory in mind must think in terms of the big picture. They must take into account the entire logistics of production, the complete development and manufacturing process of a product, and the interaction of a large number of different functional units. After all, those who have the digital factory in mind usually have big goals: Streamlining development times and consistently optimizing production and logistics processes in advance of investments, accelerating planning work and safeguarding investments. None of this is possible without simulation technology.
Model, optimize, invest
In recent years, simulation technology has produced computer-based tools that can be used to model and optimize almost all processes – from product development and general information logistics to material flows and manufacturing processes. This makes it possible to evaluate a factory concept down to the last detail as early as the planning phase and to largely avoid start-up difficulties in process and product development. At the stage of ongoing production, future modifications can be anticipated in the computer model; only after all problems encountered in the simulation have been eliminated are the processes then implemented in reality.
Typical goals of simulation studies are, for example, to increase machine utilization, to reduce resource requirements such as storage space or, more generally, to optimize control strategies. Dirk Wortmann, member of the board of SimPlan AG – one of the leading service providers in this field – describes it with the words: “Simulation technology is an aid in the planning, realization and operation of a logistics system. And we understand logistic systems to be manufacturing and assembly plants, warehouses, conveyor systems or combinations of these elements, as they are found everywhere in industry: in factories and workshops as well as in distribution centers or airports.”
According to the VDI, simulation is “the reproduction of a dynamic process in a system with the aid of a model capable of experimentation in order to arrive at findings that can be transferred to reality” (VDI Guideline 3633). What sounds so conclusive and simple in this succinct definition is, however, a difficult job in its implementation, involving considerable cost and personnel and requiring great concentration from all involved.
“Data collection for the modeling of simulation scenarios has proven to be the most time-consuming item,” Sven Spieckermann, also on the board of SimPlan AG, knows to report. The best basis for simulation is electronically available data about the process to be simulated, for example from CAD, EDM, PDM, BDE or ERP systems. The data requirements of the “simulators” often make it clear what deficits the data processing in the companies still has. Only rarely is all the required data available in DP systems; in many cases, it has to be collected at great expense. “At the same time, the data required for the simulation is usually information that is not only of interest for the simulation, but after collection leads to the well-known ‘aha’ effects for all those involved,” explains Sven Spieckermann.
Due to the extensive data requirements and the correspondingly high effort, there is a danger that successfully applied simulation techniques may increase the quality of the planning results, but slow down an ongoing planning process. The core of the virtual factory is therefore the so-called process/planning database, which ensures that all those involved in the planning process can quickly access the current data at any time. Only such a database also ensures that the digital factory is based on consistent data at all times and thus represents a true reflection of the real factory.
When deciding on the level of detail of the simulation, the rule of thumb is: as accurate as necessary (in terms of the optimization goal) and as coarse as possible (in terms of the cost-benefit calculation). Given the appropriate database and modeling, the simulation system can then easily determine the optimal solution in a series of iteration runs.
The product development process
Virtual product development is another building block for accelerating development processes. Innovative technologies such as digital mock-up (DMU) form the basis for this. This refers to systems for assembly and disassembly simulation, process simulation (manufacturing technology), and robotics and ergonomics simulation (workplace design). “The virtual factory is closely intertwined with virtual product development. Not only are the technologies similar, but there is also significant overlap in the area of data. The organizational separation of product and production development in most companies therefore also presents virtual technologies with a major challenge,” says Dirk Wortmann, explaining the connection between virtual product and virtual factory.
The decisive questions on the way to the brave new world of virtual production are similar for every company: Which path should be taken? How much and which simulation technology do we need? Does the investment pay off? In order to get the right answers, it is always advisable to consult an independent consultant. This is especially true if there is no practical experience with the simulation tool. A competent consultant can usually quickly assess whether simulation technology is the right tool for the task at hand. Furthermore, he can help the company to decide whether it is better to build up in-house simulation capacities or to commission an external service provider. When making decisions about in-house hardware and software investments, the necessary know-how must be built up in the company as quickly as possible in dialog with the consultant. The main criterion for selecting the right partner, on the other hand, is the service provider’s experience in specific areas or industries (references).
Does simulation pay off?
Finally, as far as the financial result of a simulation is concerned, this is difficult to estimate in advance. After all, the optimization potential or possible planning errors only become apparent after a simulation study has been carried out. Nevertheless, there are some indications. According to the VDI guideline already cited, for example, the cost of a simulation study can be estimated at an average of 0.5 percent and the benefit at 2.0 to 4.0 percent of the total investment sum of a project. According to information from the automotive industry, a cost-benefit ratio of 1:10 to 1:100 is quite realistic for very expensive system elements. And Simplan board member Sven Spieckermann knows from years of project work with well-known automotive companies that “the benefits of simulation can rarely be expressed in monetary terms. However, the side effects of a simulation project often generate benefits far beyond the set goal. Be it because ways to remedy deficits in data management were revealed or important action directives for practice could be derived from the global view of production processes alone.”
Conclusion: The digital factory is a great opportunity that must be seized! In practice, however, the way to get there usually involves intensive collaboration with external specialists. There is a lot to do, get to it!