Verwaltung und Verarbeitung merkmalbasierter Informationen: vom Metamodell zur technologischen Realisierung

  • Managing and processing property based information : a metamodel and its technological realization

Mertens, Martin; Epple, Ulrich (Thesis advisor)

Als Ms. gedr.. - Aachen : Publikationsserver der RWTH Aachen University (2012)
Dissertation / PhD Thesis

In: Fortschrittberichte VDI : Reihe 8, Mess-, Steuerungs- und Regelungstechnik 1207
Page(s)/Article-Nr.: XI, 164 S. : Ill., graph. Darst.

Zugl.: Aachen, Techn. Hochsch., Diss., 2011


Information based on properties plays an important role in the engineering, procurement and operation of technical plants. We regard properties as classified characteristics which are used to describe systems and which have simply formed values of standardized data types. While properties need to be highly formalized to be used in computer based systems, they are also concepts which are used for human communication as well. This ambiguous role has to be considered when modeling and managing property based information. A further challenge is the question how to manage property based information in a way that it can be used and referenced during the whole life cycle. An important question in this context is what semantics can be modeled formally and what knowledge should be managed by the humans operating with properties. Therefore, a metamodel is developed that is able to manage property based information in an integrated way. It is a basic characteristic of this model to separate the pure description of property based information from its use. Descriptions of properties are represented by so-called property types, descriptions of objects to be specified by properties are represented by so-called property carrier types. Before a property type can be assigned to a carrier type, it needs factual reference to this type. In other words, the semantics of the property type has to be explained by using the carrier type. The semantics can be represented informally, for example by using corresponding and appropriate semantic attributes, which can only be understood by the human using the model. In contrast to this, other mechanisms - for example multiple inheritance of properties within hierarchies of carrier types - can be explicitly managed and used in the model. The actual use of descriptions built up in this way is performed by model objects referring to these descriptions, the so-called property statements. These statements comply with a model of their own, which contains the statement’s intention (for example assurance, requirement, measurement, determination), its temporal validity and further administrative information. By this means, multiple groups of users can place statements within the model in different stages of the life cycle of technical systems, referencing the managed descriptions in a unified way. For example, guarantees made by a manufacturer, requirements created in the engineering stage and the current state of operation can all be represented by property statements which refer to carrier types and their properties. By creating these unified references, the basis for automated operations on property statements is provided. In addition, such operations are made possible by the fact that property statements always refer to a definite range of values of a property, independent of their intention. In this manner, ranges of values can be sorted and compared with each other. For example, it can be checked whether a guaranteed range is included in a required range of values. The metamodel is structured in a way that it can be closed on its meta layer. In this way, property types of the model layer become carrier types of the meta layer and can there be managed by using the same mechanisms. Property statements and their classification can be modeled in the same way. In order to transform this metamodel into an operating property system, a technological concept based on different layers is developed. The foundation of this concept is a distributed object management system, which can provide the different model elements as active objects that may be distributed world wide. The logic that is required to manage and process these objects is performed by several service based layers that are built upon the object management. Several roles of users and corresponding applications can access these services.