Impact and risk analysis in the integrated development of product and production system

The assessment of risks and influences of engineering changes of a product or production system on affected technical (sub-) systems of the same or a different domain are of great importance in order to evaluate possible alternatives and to select solutions. The increasing complexity of mechatronic products and production systems with Industry 4.0 technology reinforces the demand for a method that supports engineers in decision making in both technical and strategic issues. By using the method presented in this contribution, interdependencies between product functions, product features and the corresponding production processes and machines can be modelled and used to estimate the impact and risks of changes in one of those domains. Using the method, the change propagation of variations in and between the domains can be evaluated. The objective of the method is to support decision making in different use-cases like integrated product- and production system development, product variations while carrying over most of the production system or varying production processes while carrying over the product to improve production key performance indicators (KPI). Based on the model of PGE – Product Generation Engineering, the information of the reference system is used to identify the interdependencies. The inclusion of strategic factors like know-how and costs is implemented in the model, as well as the quantity and type of variations. The method consists of a representative model for a quick, holistic overview about the interdependencies and of a tool based model by using Model-Based Systems Engineering (MBSE) for an automatic connection and evaluation of the data. The contribution is part of the project I4TP - Sino German Industry 4.0 Factory Automation Platform (i4tp.org), in which a platform is developed to automatically configure a turnkey production system for a product in development

Approach for model-based requirements engineering for the planning of engineering generations in the agile development of mechatronic systems

The crucial factor for a successful usage of modeling approaches of systems engineering is the interaction of language, method, and tool. For this, specific challenges arise for the application of MBSE in agile requirements engineering. From observations in agile development practice at a machine tool manufacturer, the challenges for model-based requirements engineering are described and each is assigned to its critical aspect of modeling: The language must formally represent the requirements data model, especially for planning engineering generations. The tool must support collaborative, interdisciplinary cooperation, and consider the dynamics of the requirements model during the development process. The method must individually support the requirements engineering activities, which are carried out several times in a sprint during the development process and must enable a target-oriented process for bundling the requirements into engineering generations. Taking these demands into account, an approach is then presented providing activity-based views in conjunction with activity steps based on a consistent ontology for the description of product requirements and verification activities. The activity steps are composed in activity patterns and support the user in making use of the views for modeling requirements for the engineering generations. The approach is implemented in the software JIRA at a machine tool manufacturer. The subsequent evaluation shows that the approach is used in development practice and offers the potential to plan engineering generation systematically and comprehensibly and to ensure a regular review of the implemented requirements

Knowledge graph for manufacturing cost estimation of gear shafts - a case study on the availability of product and manufacturing information in practice

Growing cost pressure forces companies to actively manage their product costs to secure profitability. Here, manufacturing cost estimation within product development estimates manufacturing and material costs. As most products are developed in generations, needed product and manufacturing information can origin from reference system elements (RSE), for example similar components of prior product generations. Problematically, this product and manufacturing information as well as the knowledge of its interrelation is often stored in an unstructured way, document based or at least not machine-readable. This makes manufacturing cost estimation an effortful, time consuming and mainly manual activity with low traceability, where a wide manufacturing knowledge is required. Trends in production, like new manufacturing processes and production systems further increase the need for manufacturing information and knowledge. Knowledge graphs as semantic technologies can improve the findability and reusability of reference system elements and enable automatic information processing. Within this research, cost estimation of research and development of a large automotive supplier was used as research environment. Guided by the model of PGE an ontology for the manufacturing cost estimation domain was developed. Then, a knowledge graph was instantiated based on product and manufacturing information from gear shafts of electric axles. A case study was carried out to evaluate process-specific cycle time calculation as exemplary use case of the knowledge graph. Process-specific cycle times are generally effortful estimated based on detailed manufacturing information and then used together with machine hourly rates to estimate manufacturing costs. Here, the structured and machine-readable manufacturing information of identified reference system elements is extracted from the knowledge graph to reduce the effort, increase the traceability and enable future automation. The case study shows exemplary, how a knowledge graph can support manufacturing cost estimation of gear shafts where product and manufacturing information is automatically identified using reference system elements

Improving system of objectives maturity through systematic reuse of knowledge using ontology-based knowledge representations

Technical products are developed to meet the needs of different stakeholders. In addition, various constraints from all phases of the product life cycle have to be considered. In existing work, this information and its dependencies are systematically represented in the so-called system of objectives. A major challenge in modeling the system of objectives is that the necessary information in the system of objectives is often incomplete and uncertain. In addition, this uncertainty and the maturity of the system of objectives cannot be directly quantified because the target state of the system of objectives often cannot be unambiguously described. This research investigates a methodical approach to assess and improve the maturity of the system of objectives. Two means to reduce uncertainty and thus increase the maturity of the system of objectives are the systematic reuse of knowledge and the systematic building of knowledge through verification and validation activities

Implementation and Assessment of a Comprehensive Model-Based Systems Engineering Methodology with Regard to User Acceptance in Practice

Model-Based Systems Engineering (MBSE) is becoming increasingly popular, not only in research but also in industrial companies. However, MBSE approaches (i.e. methods, frameworks, ontologies, and tools) are usually developed at a scientific level, so that they are too generic and formal for a company\u27s internal use leading to acceptance issues in industrial practice. Against this background, this contribution presents a comprehensive user-oriented MBSE methodology tackling this lack of acceptance in industrial practice. Based on ten previously derived fields of action for individual and organizational acceptance of MBSE approaches, a first positive evaluation of the MBSE methodology has been received. In this contribution, a further developed MBSE methodology is presented, which is created in cooperation of partners from research and industry. Assessment of this further developed MBSE methodology with six companies across different industries shows a positive impact on acceptance in comparison to existing MBSE approaches across the identified fields of action. Major improvements are seen regarding the perceived performance and benefit of MBSE, the usability of the modeling tool, and the communication within a development team. Smaller improvements are noted regarding the establishment of a clear target picture and modeling process, as well as in tackling ambiguity when modeling in a development team. In addition, research at one of the industrial partners shows that company-specific tailoring and implementation of the developed MBSE methodology can be performed in a fast and straightforward way

Model-Based Engineering für die Automatisierung von Validierungsaktivitäten am Beispiel Fahrerassistenzsysteme

Dieser Beitrag untersucht Potenziale des Einsatzes von MBE-Ansätzen bei der Validierung von Fahrerassistenzsystemen. Ziel ist die Untersuchung der Machbarkeit des Aufbaus einer Validierungsumgebung zur Automatisierung von Tests im Rahmen der kontinuierlichen Validierung von Fahrerassistenzsystemen. [... aus der Einleitung

SUPPORTING SYSTEMS ENGINEERING ACTIVITIES BY ARTIFACT-ORIENTED DESCRIPTION AND SELECTION OF METHODS

Systems Engineering (SE) is becoming increasingly relevant in industrial application since more stakeholders are involved in engineering activities. To implement SE, companies have to adapt existing engineering processes and methods. This adaption requires knowledge about new methods as well as their integration into the engineering activities. In order to ensure goal-oriented identification of methods for different SE activities in this contribution an action field profile and the Systems Engineering Method Matrix are proposed. The development of both tools is driven by the assumption that most SE activities and methods can be described based on the artefacts the deliver. In order to get feedback about the proposed tools, semi-structured interviews with two industry partners were conducted, focussing on the tool\u27s usability. These interviews underline the basic usability of the tools and their support to identify SE activities to be supported by (new) methods. Moreover, requirements for further development and adaption are derived from the interviews

Functional analyses of AGAMOUS family members in Nicotiana benthamiana clarify the evolution of early and late roles of C-function genes in eudicots

[EN] The C-function, according to the ABC model of floral organ identity, is required for stamen and carpel development and to provide floral meristem determinacy. Members of the AG lineage of the large MADS box gene family specify the C-function in a broadly conserved manner in angiosperms. In core eudicots, two sub-lineages co-exist, euAG and PLE, which have been extensively characterized in Antirrhinum majus and Arabidopsis thaliana, where strong sub-functionalization has led to highly divergent contributions of the respective paralogs to the C-function. Various scenarios have been proposed to reconstruct the evolutionary history of the euAG and PLE lineages in eudicots, but detailed functional analyses of the roles of these genes in additional representative species to validate evolutionary hypotheses are scarce. Here, we report functional characterization of euAG- and PLE-like genes in Nicotiana benthamiana through expression analyses and phenotypic characterization of the defects caused by their specific down-regulation. We show that both paralogs redundantly contribute to the C-function in this species, providing insights on the likely evolution of these gene lineages following divergence of the major groups within the eudicots (rosids and asterids). Moreover, we have demonstrated a conserved role for the PLE-like genes in controlling fruit dehiscence, which strongly supports the ancestral role of PLE-like genes in late fruit development and suggests a common evolutionary origin of late developmental processes in dry (dehiscent) and fleshy (ripening) fruits.We thank Rafael Martinez-Pardo and Eugenio Grau for technical support, Amy Litt (New York Botanical Gradens, Bronx, NY, USA) for providing VIGS plasmids, Eugenio Minguet for help with the LFY matrix and Morpheus tool, and Francisco Madueno, Monica Colombo and Barbara Ambrose (NYBG) for critical reading of the manuscript. The work was funded by grant BIO2009-09920 from the Spanish Ministerio de Ciencia e Innovacion to C.F.Fourquin, C.; Ferrandiz Maestre, C. (2012). Functional analyses of AGAMOUS family members in Nicotiana benthamiana clarify the evolution of early and late roles of C-function genes in eudicots. Plant Journal. 71(6):990-1001. https://doi.org/10.1111/j.1365-313X.2012.05046.xS990100171