J. v. Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5/WG3-N695, ANSI, 11 West 42nd Street, New York, NY 10036, 1982.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....of a system [13] based on the interrogatives of the English language. This leads to aspects such as: what, how, when, why, and where. Level of abstraction. What level of abstraction, with respect to the systems under consideration, is the method component focused at Examples (derived from [4]) are: conceptual level, logical level, and physical level. Communication style. What is the communication style used in describing the method component Some examples are: reference material, study material, and teaching material. Natural language used. What is the language used to ....

J. v. Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5/WG3-N695, ANSI, 11 West 42nd Street, New York, NY 10036, 1982.

....is their incapability of representing complex structures in a natural way. In these techniques, complex structures have to be flattened , i.e. represented non hierarchically, which leads to overspecification. This in turn does not comply with the conceptualisation principle as it is formulated in [Gri82]. Various application domains indeed contain objects with complex structures. Documents (and Hypertexts) are an example in the field of office automation. In [Wig90] it is estimated that 1 of all recorded information is contained in so called formatted databases (e.g. a relational database) 4 ....

....required to determine the type of the Product. This determination forms the Subtype Defining Rule for Products (see figure 4) However, these extra object types are not conceptually relevant. Their introduction should therefore be considered as a violation of the Conceptualisation Principle (see [Gri82], NH89] or [Win90] Zip Code] Car [Reg Nr] House [House Nr] Product Amount [ has is of has is of has price is price of U Figure 5: Example of Generalisation Using the concept of generalisation, these overspecifications are avoided. In figure 4 a more appropriate schema for ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....states. Considering an information system from a systems view on organizations (e.g. Lin90] an information system should allow evolution to the same extent and at the same pace at which an organization system evolves because of changes in the organization domain (universe of discourse, Gri82] However, most traditional information systems hardly support any aspects of evolution. First of all, most traditional systems mainly focus on the static aspects of the organization system. Apart from that, they allow update of the information base only, i.e. the set of facts which obeys a ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....difference between a traditional information system, and its evolving counterpart, will become clear. This is followed by a discussion on how the evolution of a universe of discourse can be dealt with. 2. 1 The Extent of Evolution A complete specification of a universe of discourse typically ( Gri82] contains the following components: 1. an intentional description of the set of states, also called the underlying information structure. 2. a further refinement of the set of states by means of static constraints. 3. an intentional description of the set of transitions that can be performed ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....counterparts. For a sound conceptualisation, a technique should fulfill a set of often cited (albeit various in terminology) requirements. If not properly catered for, the development of workflow specifications may be problematic. First and most naturally, the Conceptualisation Principle [Gri82] positions a technique on essence. In this regard, business models of workflow specification languages can prescribe organisational infrastructure, thereby compromising conceptualisation, while an execution only focus can deflect it altogether. Conversely, following the One Hundred Percent ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....For the conditional this could look like: conditional thenbranch: statement ; elsebranch: statement ; condition: boolean expression . In a sense, the abstract syntax can be compared to what is referred to as the conceptual level in the famous three level architecture of [Gri82] The conceptual level focusses on concepts as they are and not on how they are perceived (external level) or implemented (internal level) While leaving the phase of infancy behind in the field of information systems, it is clear that a shift from representational issues to more conceptual ....

....adaptable to new requirements and specifications that are general are easier to understand than those laced with details and choices which are too specific. In the field of data modelling one may argue that the notion of generality is closely related to the famous Conceptualisation Principle [Gri82] which states that conceptual models should deal only and exclusively with aspects of the problem domain. Any aspects irrelevant to that meaning should be avoided, as this might lead to exclusions of possible solutions in too early a stage. The concepts of conceptualization and generality ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5/WG3-N695, ANSI, 11 West 42nd Street, New York, NY 10036, 1982.

....design. Workflow modelling requirements naturally derive from generic requirements for information modelling techniques as promulgated by e.g. Hof93] In this section the criteria for a good workflow modelling language will be presented. Conceptual The famous Conceptualisation Principle ([Gri82]) states that conceptual models should deal only and exclusively with aspects of the problem at hand. Any aspects irrelevant to that meaning, e.g. aspects of (internal or external) data representation, physical data organisation and access as well as aspects of particular external user ....

....of view (see e.g. Aal97, AH98, HOR98] The consequences however are that few workflow specifications are thoroughly checked before they are deployed in practice, which often results in errors having to be corrected in an ad hoc fashion often at prohibitive costs. Expressive The 100 principle ([Gri82]) states that a conceptual model should describe all relevant static and dynamic aspects of the problem at hand. This implies that a language should have sufficient expressive power. Create Purchase Requisition OR Receive the delivery batch Check if more delivery needed Process ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5/WG3-N695, ANSI, 11 West 42nd Street, New York, NY 10036, 1982.

....schema. are always either a or a . Since s are identified through their registration nr, and s thtough their part id, all s can indeed be identified. The introduction of the artificial identification in the NIAM schema may be considered as a violation of the Conceptualisation Principle (see [37], 1] since it was not present in the original universe of discourse. 3.2 Population For each database state, a type is populated by a set of instances. The notion of population can be modelled formally by the total function: Here denotes the domain of values. The population of a subtype ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....to evolution. From this identification, the difference between a traditional information system, 3 and its evolving counterpart, will become clear. This is followed by a discussion on how the evolution of an information system is modelled. 2. 1 The extent of the corpus evolutionis According to [Gri82] a conceptual (i.e. complete and minimal) specification of (a version of) a universe of discourse consists of the following components: 1. an information structure, a set of constraints and a population conforming to these requirements. 2. a set of action specifications describing the ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....that may be subject to evolution. From this identification, the difference between a traditional information system, and its evolving counterpart, will become clear. This is followed by a discussion on how the evolution of an information system is modelled. 2. 1 A hierarchy of models According to [18], a conceptual (i.e. complete and minimal) specification of (a version of) a universe of discourse consists of the following components: 1. an information structure, a set of constraints and a population conforming to these requirements. 2. a set of action specifications describing the ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....constraints, but also queries and updates can be expressed on a conceptual level. 1 Introduction Currently, many conceptual data modelling techniques exist. Conceptual data modelling techniques aim at the representation of data at a high level of abstraction. The Conceptualisation Principle ([14]) states that a conceptual schema should deal only and exclusively with aspects of the underlying Universe of Discourse (UoD) Any aspect irrelevant to that meaning, e.g. machine efficiency, should be avoided. Contemporary data modelling techniques are not capable of adhering to the ....

....the UoD has to be adapted, e.g. extra object types have to be introduced, to meet the requirements of the modelling technique. These problems are caused by the lack of sufficiently powerful construction mechanisms. Another important principle of conceptual data modelling is the 100 Principle ([14]) which states that a conceptual schema completely prescribes all the permitted states and transitions of the conceptual data base. This implies that a conceptual data modelling technique should not only be capable of representing complex structures but also rules (constraints) that must hold for ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....when building information systems. This means that data must be modelled first on conceptual level, and then the obtained conceptual model (conceptual schema) must be translated to the external and internal level, according to the three level architecture for information systems modelling ([16]) By doing so, the issues of correctness and efficiency are well separated, which is quite desirable. In this paper we deal with the transformation of conceptual data models into internal (implementation oriented) database models. During the past decades a number of conceptual data modelling ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....of sentences, will be discussed in more detail in section 4. 2. 3 Language is referential Besides the fact that we know how to put words into meaningful sentences, we also know which words refer to which things, scenes and events in the real world around us, also called Universe of Discourse ( Gri82] Take as an example the sentence: That s a rabbit. The words are put together into a sentence in a correct and meaningful way. However, when this sentence was uttered by a little boy while pointing at a dog, we would not think he has learned English very effectively. This problem is called ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

.... This framework should clarify the precise meaning of fundamental data modeling concepts and offer a sufficient level of abstraction to be able to concentrate on this meaning and avoid distractions of particular mathematical representations (in a sense, the well known Conceptualization Principle [Gri82] can also be applied to mathematical formalizations) These requirements suggest category theory (see e.g. BW90] as an excellent candidate. Category theory provides a sound formal basis and abstracts from all representational aspects. Therefore, the framework will be embedded in category ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....much of the workflow ontology standardised by the WMC is clearly implementation oriented and leaves the critical issue of workflow conceptualisation open. In one form or another, the requirements which lead to effective conceptual modelling are that: following the Conceptualisation Principle [Gri82] a technique should adhere strictly to the conceptual level; following the One Hundred Principle, a technique should provide a high degree of expressive power ; at the same time, a technique should facilitate comprehensibility ; and should be backed up by a formal foundation whereby both the ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

.... This framework should clarify the precise meaning of fundamental data modelling concepts and offer a sufficient level of abstraction to be able to concentrate on this meaning and avoid distractions of particular mathematical representations (in a sense, the wellknown Conceptualisation Principle [Gri82] can also be applied to mathematical formalisations) These requirements suggest category theory (see e.g. BW90] as an excellent candidate. Category theory provides a sound formal basis and abstracts from all representational aspects. Therefore, the framework will be embedded in category ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....Moreover, the models should force active participation of users by stimulating and generating questions as to how reality is abstracted and assumptions are made. A number of desirable properties for a requirements specification (defined in the form of a conceptual schema) have been proposed [4, 34, 32, 24] and can be summarised as follows. Implementation Independence. No implementation aspects such as data representation, physical data organisation and access, as well as aspects of particular external user representation, such as message formats, data structures, etc) should be included in a ....

van Griethuysen, J.J. et al (eds), "Concepts and Terminology for the Conceptual Schema and the Information Base", Report ISO TC97/SCS/WG3, 1982, Publication No. ISO/TC97/SC5 - N 695.

....concept of worldview to model the pluggable components. This construct also allows us to derive polymorphism and a subtype relationship. 2 Starting point An (object oriented) model is a projection of some part of the real or an imaginary world This part is called universe of discourse in [Gri82] We use objects as artificial modelling constructs to make a simplified, understandable model of the universe of discourse. We don t claim that there are objects in the real world. We take a modest position and see the universe of discourse as far too complex for us to grasp. Objects are used ....

....when they don t necessarily have a distinguishing property We put labels on the objects for this purpose. As long as we ensure that each object is labeled uniquely, these labels represent the implicit identity of the objects. One might say that this violates the conceptualization principle (see [Gri82] which states that conceptual models should deal only and exclusively with aspects of the universe of discourse and that any aspects irrelevant to that meaning, like the artificial introduction of identifying codes, should be avoided. We argue however, that putting labels on objects does not ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....e.g. CG85] In this paper we focus on the first aspect. We consider this problem as follows: for a given conceptual data model, find an internal representation (database structure) with optimal storage requirements and response times. For a general introduction into the main concepts we refer to [Gri82]. Dept. of Information Systems, Faculty of Mathematics and Informatics, University of Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands, E mail: pvb cs.kun.nl The conceptual data models we use consist of so called fact types between object types (see e.g. NH89] We do not consider ....

....what kind of data must be stored in a system (see e.g. ER [Che76] and NIAM [NH89] The process of database design is then initiated with this conceptual model. It results in an internal representation (database structure) specifying in what way the data is represented on a computer (see also [Gri82]) For a given conceptual data model, the set S of all possible internal representations may be very large. This set S is usually called the search space (or solution space) of the optimisation problem under consideration. Some elements of S will result in an efficient system, others will not. We ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....modelling, hypertext, object role models, ER, NIAM, identification. 1 Introduction In the past years, many conceptual data modelling techniques have been introduced. Well known examples are the Relational model ( 6] the ER approach ( 5] and NIAM ( 38] 25] The Conceptualisation Principle ([11]) requires that conceptual schemas should deal only and exclusively with aspects of the Universe of Discourse (UoD) Any aspects irrelevant to that meaning, e.g. machine efficiency, should be avoided. In complex application domains contemporary data modelling techniques are not always capable of ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....PSF [MV90] specification of a Car Registration Authority . The Car Registration Authority (CRA) models the production and sale of cars. Our specification of CRA is reminiscent to the one described by Wieringa [Wie90] The origins of CRA are described by van Griethuysen in the ISO 1982 report [Gri82]. The specification described here has been simulated using the PSF toolkit [Vel93] 2 2 PSF SPECIFICATIONS The tasks of CRA as specified in this paper are to register who was the owner of a car at any moment from production to destruction of the car, and to monitor certain laws, for example ....

J.J. van Griethuysen. Concepts and terminology for the conceptual schema and the information base. Technical Report ISO TC97/SC5/WG3, 1982.

....: 8 3. 2 Typing a logbook : 9 4 Conclusions 11 1 Introduction Many conceptual modeling methods have as point of departure an initial specification of the world to be modeled, also referred to as Universe of Discourse ([Gri82]) or UoD for short. This initial specification is usually expressed in natural language. The goal of the modeling process is to obtain a complete consistent formal specification from the initial specification. Only a few conceptual modeling methods provide the system analyst with clues and rules, ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

....definitions in this paper. For more advanced conceptual modelling constructs, the reader is referred to e.g. PSM ( HW93] and IFO ( AH87] 2. 2 Internal representation mechanism In this section a mechanism is discussed for representing conceptual information structures on the internal level ( Gri82] Intuitively, such a representation is the result of lifting up certain atomic object types of the information structure and cutting the connections between these object types. Formally, a forest (set of trees) T = hN ; E; i is called an internal representation for information structure I if ....

J.J. van Griethuysen, editor. Concepts and Terminology for the Conceptual Schema and the Information Base. Publ. nr. ISO/TC97/SC5-N695, 1982.

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