Concept for modeling and quantitative evaluation of life cycle dynamics in factory systems

Against the background of the climate crisis, fast innovation space in emerging technologies and the global competitive environment for manufacturing companies, a sound understanding of the life cycle behavior of factory systems becomes more and more important. The decision context of the factory life cycle conveys a high level of complexity, e.g. by the heterogeneous nature of factory element life cycles, manifold interactions between them as well as external change drivers. A model-based understanding as well as methods and tools are required that support factory planners and operators in this regard. This paper presents an approach for the modeling and quantitative evaluation of life cycle dynamics in factory systems while respecting the dynamic behavior of factory operation, as well. The purpose of the modeling is to deepen the knowledge of the prevailing life cycle mechanisms and their implications for factory planning and operation. The application of the approach is demonstrated in an exemplary case study

Evaluation of the influence of change drivers on the factory life cycle

Factories consist of numerous factory elements with individual life cycles. Besides technical aspects such as wear, their actual lifetime is influenced by change drivers from an increasingly dynamic market environment. As a result, factory elements may experience a premature end due to changed requirements before the end of their technical lifetime. The difficulty in factory planning is to understand the behavior of the life cycles in order to make management decisions. Therefore, the goal is to identify change drivers and evaluate their influence on the factory life cycle, while taking into account the technical functionality

A review of frameworks, methods and models for the evaluation and engineering of factory life cycles

Factories are complex systems, which are characterized by interlinked and overlapping life cycles of the constituent factory elements. Within this context, the heterogeneity of these life cycles results in life cycle complexity and corresponding conflicts and trade-offs that need to be addressed in decision situations during the planning and operation of factory systems. Also with respect to the transformation need towards environmental sustainability, there is a need for methods and tools for life cycle oriented factory planning and operation. This paper systematically reviews existing life cycle concepts of factory systems as well as frameworks, models and methods for the evaluation and engineering of factory life cycles. In order to respond to the above challenges, a general understanding about the factory life cycle, e.g. life cycle stages, related activities and interdependencies, is developed and action areas of life cycle engineering are discussed that could supplement factory planning. Following that, the paper presents an integrated, model-based evaluation and engineering framework of factory life cycles. © 2022 The Author

Towards a Holistic Life Cycle Costing and Assessment of Factories: Qualitative Modeling of Interdependencies in Factory Systems

Modern factory planning requires a holistic perspective taking economic as well as environmental sustainability over the entire factory life cycle into account. As a complex socio-technical system, the factory life cycle consists of multiple life cycles of the inherent factory elements. A holistic understanding of the individual life cycles and their interdependencies is missing for both planning and operation of a factory. Therefore, the goal is to develop a system understanding about life cycle-oriented factory planning and to analyze the contribution of relevant factory elements to the sustainability of a factory. As a result, a knowledge base for life cycle costing and assessment of the entire factory is established using an impact path model. The qualitative model supports factory planners in deriving planning measures for the sustainable design of a factory and in determining data requirements for the quantitative evaluation of the economic and environmental sustainability of a factory. It shows that the production and logistics concepts essentially define the sustainability potential during planning, while the resulting life cycle behavior of the process facilities and workers is responsible for the majority of costs and environmental impacts of a factory. Factory planners must therefore become aware of the implications of planning decisions on factory operation when developing concepts in the future

Factory life cycle evaluation through integrated analysis of factory elements

In consequence of the technological advances of the last few decades, factories emerged to highly complex systems that consist of numerous factory elements like production machines, technical building services and the building shell. These factory elements are characterized by individual life cycles that differ in their duration and life cycle behavior. Consequently, the factory life cycle is composed of multiple overlapping life cycles. The fact that the life cycle of some factory elements (e.g. the building shell) exceeds the life cycle of other elements over many times (e.g. of machines) presents a challenge for factory planners. In particular, factory planners struggle to understand the contribution of single factory elements on the total factory life cycle. Consequently, it is hard to systematically synchronize the inherent life cycles of a factory while adhering to manifold requirements. Against this background, the goal of this paper is to develop a methodology that supports factory planners in the evaluation of the factory life cycle. The proposed methodology enhances the understanding of how factory elements contribute to the factory life cycle and what is the current life cycle state of the entire factory. To this end, the factory system is broken down on its constituting elements. A modified failure mode and effect analysis (FMEA) is applied to assess their life cycle priority according to economic, environmental and technical criteria. The methodology is exemplarily demonstrated on a pilot scale battery production system

Integrated computational product and production engineering for multi-material lightweight structures

Within product development processes, computational models are used with increasing frequency. However, the use of those methods is often restricted to the area of focus, where product design, manufacturing process, and process chain simulations are regarded independently. In the use case of multi-material lightweight structures, the desired products have to meet several requirements regarding structural performance, weight, costs, and environment. Hence, manufacturing-related effects on the product as well as on costs and environment have to be considered in very early phases of the product development process in order to provide a computational concept that supports concurrent engineering. In this contribution, we present an integrated computational concept that includes product engineering and production engineering. In a multi-scale framework, it combines detailed finite element analyses of products and their related production process with process chain and factory simulations. Including surrogate models based on machine learning, a fast evaluation of production impacts and requirements can be realized. The proposed integrated computational product and production engineering concept is demonstrated in a use case study on the manufacturing of a multi-material structure. Within this study, a sheet metal forming process in combination with an injection molding process of short fiber reinforced plastics is investigated. Different sets of process parameters are evaluated virtually in terms of resulting structural properties, cycle times, and environmental impacts. © 2020, The Author(s)

BspRI restriction endonuclease: cloning, expression in Escherichia coli and sequential cleavage mechanism

The GGCC-specific restriction endonuclease BspRI is one of the few Type IIP restriction endonucleases, which were suggested to be a monomer. Amino acid sequence information obtained by Edman sequencing and mass spectrometry analysis was used to clone the gene encoding BspRI. The bspRIR gene is located adjacently to the gene of the cognate modification methyltransferase and encodes a 304 aa protein. Expression of the bspRIR gene in Escherichia coli was dependent on the replacement of the native TTG initiation codon with an ATG codon, explaining previous failures in cloning the gene using functional selection. A plasmid containing a single BspRI recognition site was used to analyze kinetically nicking and second-strand cleavage under steady-state conditions. Cleavage of the supercoiled plasmid went through a relaxed intermediate indicating sequential hydrolysis of the two strands. Results of the kinetic analysis of the first- and second-strand cleavage are consistent with cutting the double-stranded substrate site in two independent binding events. A database search identified eight putative restriction-modification systems in which the predicted endonucleases as well as the methyltransferases share high sequence similarity with the corresponding protein of the BspRI system. BspRI and the related putative restriction endonucleases belong to the PD-(D/E)XK nuclease superfamily

Lebenszyklusplanung von Fabriksystemen

Life cycle planning in production engineering often only addresses the life cycle of one or multiple products. However, the life cycle of the factory system to produce those products is also relevant in the context of environmental sustainability. Therefore, a sound understanding of the factory life cycle becomes increasingly important for the planning and operation of factory systems with regard to environmental targets. Decisions during factory planning predominantly predetermine the later environmental performance. The decision context is highly complex as it entails heterogeneous life cycles and manifold interactions. Existing approaches as well as methods and model-based support tools fail to provide a comprehensive understanding of the factory life cycle. Therefore, a concept for the life cycle planning of factory systems is presented in the thesis. A strong interaction between data, modeling methods and visualization techniques is proposed that facilitate deepening the knowledge about the factory life cycle and pave the way for life cycle engineering of factory systems. Particularly, the work developed a factory life cycle understanding that enables a multifaceted perspective on the involved heterogeneous life cycles and their interrelationships as well as the dynamic interrelationships between factory elements during factory operation. The presented concept extends the scope of previous approaches to the whole life cycle of a factory system. Beyond a descriptive factory system decomposition model, two modeling approaches on different abstraction levels are proposed that facilitate on the one hand the anticipation of long-term developments and on the other hand provide detailed insights into the operational and environmental performance of process chains. This combination is unique and stands out from previous work in the context of factory life cycle evaluation. The developed factory decomposition model contributes to break down the life cycle of the factory on relevant factory elements, their life cycles, interrelationships between the life cycles and environmental performance indicators. Generic modeling of the factory life cycle behavior addresses the factory life cycle on a longer time scale. The outcome is a general understanding of long-term, time-dependent interactions, e.g. the aging patterns of factory elements. In contrast, life cycle oriented process chain modeling targets the detailed representation of the operational behavior and environmental performance of process chains on a shorter planning horizon. In this respect, energy and material flows as well as the process chain-inherent dynamics are modeled in detail. This enables the quantitative evaluation of the operational and environmental performance of a process chain from factory and product perspective. The visualization and evaluation techniques embrace tailored visualizations for the analysis of life cycle related interrelationships, for the illustration of environmental impacts over the factory life cycle in a circular layer model and a break-even analysis. The concept modules were prototypically implemented as standalone software tools and as an integrated interactive dashboard. The dashboard allows for building up an enhanced life cycle understanding of the factory system by interaction with the models and visual data exploration. Two exemplary case studies demonstrate the application of the life cycle planning concept. First, a greenfield planning of a battery cell factory with a focus on the qualitative assessment and the circular layer model is presented. The second case, a brownfield planning project, focuses on the application of the generic life cycle modeling and the break-even analysis for life cycle planning of a crankshaft production line.Lebenszyklusplanung umfasste in der Produktionstechnik bisher lediglich den Lebenszyklus eines oder mehrerer Produkte. Mit Hinblick auf die ökologische Nachhaltigkeit ist jedoch auch der Lebenszyklus des Fabriksystems relevant, wo diese Produkte hergestellt werden. Ein fundiertes Verständnis des Fabriklebenszyklus wird daher in der Planung und dem Betrieb von Fabriksystemen immer wichtiger, um ökologische Zielvorgaben zu erreichen. Entscheidungen während der Fabrikplanung bestimmen maßgeblich die späteren Umweltwirkungen während der Errichtung und dem Betrieb der Fabrik. Der Entscheidungskontext ist dabei sehr komplex, da heterogene und miteinander wechselwirkende Lebenszyklen berücksichtigt werden müssen. Bestehende Ansätze sowie Methoden und modellbasierte Werkzeuge bieten kein umfassendes Verständnis des Fabriklebenszyklus. Daher wird in dieser Arbeit ein Konzept für die Lebenszyklusplanung von Fabriksystemen vorgestellt. Das Konzept sieht eine starke Interaktion zwischen Daten, Modellierungsmethoden und innovativen Visualisierungstechniken vor, die Wissen über den Fabriklebenszyklus generiert und den Rahmen für das Life Cycle Engineering von Fabriksystemen aufspannt. Insbesondere wurde in der Arbeit ein Fabriklebenszyklusverständnis entwickelt, das einen differenzierten Blick auf die heterogenen Lebenszyklen der Fabrikobjekte und deren Zusammenhänge sowie auf die dynamischen Wechselbeziehungen zwischen den Fabrikobjekten während des Fabrikbetriebs ermöglicht. Das vorgestellte Konzept erweitert den Betrachtungsrahmen bisheriger Ansätze auf den gesamten Lebenszyklus des Fabriksystems. Über ein deskriptives Fabrikdekompositionsmodell hinaus umfasst das Konzept zwei weitere Modellierungsansätze auf unterschiedlichen Abstraktionsebenen, die einerseits die Antizipation langfristiger Entwicklungen ermöglicht und andererseits detaillierte Einblicke in das operative und ökologische Verhalten von Prozessketten bietet. Diese Kombination ist einzigartig und hebt sich von früheren Lebenszyklusbewertungsansätzen von Fabriken ab. Das entwickelte Fabrikdekompositionsmodell trägt dazu bei, den Lebenszyklus der Fabrik auf relevante Fabrikelemente, ihre Lebenszyklen, Wechselbeziehungen zwischen den Lebenszyklen und Umweltkennzahlen herunterzubrechen. Die generische Modellierung des Lebenszyklusverhaltens einer Fabrik strebt die Modellierung der Fabrikobjekte auf einer längeren zeitlichen Perspektive an. Das Ergebnis ist ein allgemeines Verständnis der langfristigen, zeitabhängigen Wechselwirkungen, z. B. der Alterungsmuster von Fabrikobjekten. Im Gegensatz dazu zielt die lebenszyklusorientierte Prozesskettenmodellierung auf die detaillierte Analyse des operativen Verhaltens und den Umweltwirkungen von Prozessketten auf einem kürzeren Planungshorizont ab. Dabei werden Energie- und Materialströme sowie die prozessketteninhärente Dynamik detailliert modelliert. Dies ermöglicht eine quantitative Bewertung sowohl aus Fabrik- als auch aus Produktsicht. Die Visualisierungs- und Bewertungstechniken umfassen maßgeschneiderte Visualisierungen zur Analyse lebenszyklusbezogener Zusammenhänge, zur Darstellung von Umweltwirkungen in einem Zwiebelschalenmodell und eine Break-Even-Analyse. Die Konzeptbausteine wurden prototypisch als eigenständige Softwaretools umgesetzt. Zusätzlich ist ein Dashboard konzipiert worden, das den interaktiven Aufbau von Wissen durch Kombination der einzelnen Softwaremodule ermöglicht. Zwei exemplarische Fallstudien demonstrieren die Anwendung des Konzepts. Zunächst wird eine Greenfield-Planung einer Batteriezellenfabrik mit Schwerpunkt auf der qualitativen Bewertung und dem Zwiebelschalenmodell vorgestellt. Der zweite Fall, ein Brownfield-Planungsprojekt, konzentriert sich auf die Anwendung der generischen Lebenszyklusmodellierung und der Break-even-Analyse für die Lebenszyklusplanung einer Kurbelwellenproduktionslinie

Machine learning and simulation-based surrogate modeling for improved process chain operation

In this contribution, a concept is presented that combines different simulation paradigms during the engineering phase. These methods are transferred into the operation phase by the use of data-based surrogates. As an virtual production scenario, the process combination of thermoforming continuous fiber-reinforced thermoplastic sheets and injection overmolding of thermoplastic polymers is investigated. Since this process is very sensitive regarding the temperature, the volatile transfer time is considered in a dynamic process chain control. Based on numerical analyses of the injection molding process, a surrogate model is developed. It enables a fast prediction of the product quality based on the temperature history. The physical model is transferred to an agent-based process chain simulation identifying lead time, bottle necks and quality rates taking into account the whole process chain. In the second step of surrogate modeling, a feasible soft sensor model is derived for quality control over the process chain during the operation stage. For this specific uses case, the production rejection can be reduced by 12% compared to conventional static approaches