1、Standard ECMA-270December 1997Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chPortable Common Tool Environment(PCTE) - Mapping from CASE DataInterchange Format (CDIF) to PCTE.Standard ECMA-270Decem
2、ber 1997Standardizing Information and Communication SystemsPhone: +41 22 849.60.00 - Fax: +41 22 849.60.01 - URL: http:/www.ecma.ch - Internet: helpdeskecma.chIW Ecma-270.doc 07-01-98 15,45Portable Common Tool Environment(PCTE) - Mapping from CASE DataInterchange Format (CDIF) to PCTE.Brief HistoryP
3、CTE, Portable Common Tool Environment, is an interface standard. The interface is designed to support program portabilityby providing machine-independent access to a set of facilities. These facilities, which are described in the PCTE AbstractSpecification (Standard ECMA-149), are designed particula
4、rly to provide an infrastructure for programs which may be part ofenvironments supporting systems engineering projects. Such programs, which are used as aids to systems development, areoften referred to as tools.CDIF, CASE Data Interchange Format, is a standard of the Electronic Industries Associati
5、on. CDIF was defined primarily as astandard for exchanging models between CASE tools. Since it is necessary for parties that exchange models to have a commonunderstanding of them, CDIF is not just a standard for a transfer format, but also for an integrated meta-model (schema) of thedata and process
6、 models that can be exchanged. This harmonises the concepts of different methods and viewpoints, makingCDIF independent of particular methods and tools.This ECMA Standard for a mapping from CDIF to PCTE allows PCTE schemas (SDSs) to be derived from the CDIFintegrated meta-model. Models defined with
7、such SDSs can be freely exchanged using CDIF. Derived SDSs are included inthis ECMA Standard; they provide a substantial information model for any PCTE-based software engineering environment orrepository.From the first meeting of ECMA/TC33 for standardizing PCTE, it was recognized that additional st
8、andards would be requiredto achieve the final aim of integrating independently produced tools in a software engineering environment. A task group (TaskGroup for the Reference Model, TGRM) was formed to study the requirements. Two of the areas in which further standardswere required were data interch
9、ange between PCTE-based repositories and SDSs for software engineering tools.After ECMA/TC33 received a presentation of CDIF in 1991, there was enough interest in the possibility of basing a PCTEstandard for data exchange on the use of CDIF for TC33 to extend the scope of TGRM for such work. TGRM wa
10、s laterrenamed Task Group for Data Interchange, TGDI. The work on data exchange progressed with the attendance of CDIFrepresentatives. This close co-operation was formalised by the agreement of a Memorandum of Understanding betweenECMA/TC33 and the EIA CDIF Division.Meanwhile an international initia
11、tive had started in 1991 for co-ordinating the activities of several bodies concerned withstandards for describing or interchanging software engineering models. This resulted in the approval of an ISO/IEC JTC1project 7.28 Software Engineering Data Description and Interchange (SEDDI) which was assign
12、ed to SC7/WG11 in 1992.JTC1/SC7 accepted EIA CDIF as a Category C liaison. New versions of CDIF, taking account of WG11 comments oninternationalization, were published as EIA Interim Standards from 1994 onwards. WG11 agreed to use these versions for itsSEDDI standard.The scope of SEDDI included PCTE
13、 SDSs corresponding to the SEDDI meta-model. The PCTE SDSs were to be produced inconjunction with ECMA/TC33 through ECMAs Category A liaison with JTC1. The work progressed slowly in ECMA/TC33owing to its limited resources being focused on the extensions of PCTE for fine-grain objects and object-orie
14、ntation. It wasgiven a fresh impetus in 1996 with a joint project between Fujitsu and ICL for prototyping CDIF with a PCTE repository. Thework was completed by ECMA/TC33 in close liaison with JTC1/SC7/WG11 and JTC1/SC22/WG22 (PCTE).This ECMA Standard has been adopted by the General Assembly of Decem
15、ber 1997.- i -Table of contents1 Scope 12 Conformance 12.1 Conformance of an SDS 12.2 Conformance of a PCTE tool 13 Normative references 14 Terms and definitions 24.1 CDIF and PCTE terms 24.2 Other terms 24.2.1 CASE tool 24.2.2 derived SDS 24.2.3 model 24.2.4 PCTE model 24.2.5 PCTE tool 24.2.6 SDS f
16、or a (given) CDIF subject area 25 Symbols (and abbreviated terms) 35.1 Notations 35.2 Abbreviations 35.2.1 CDIF 35.2.2 DDL 35.2.3 PCTE 35.2.4 SDS 36 Outline of the Standard 37 Mapping principles 38 Issues for the mapping 48.1 Mapping of names 48.1.1 Uniqueness of Names 48.1.2 Syntax of Names 48.1.3
17、Basic mapping of names 48.1.4 Duplication of names 48.2 Subtyping of meta-entities 58.3 Subtyping of meta-relationships 58.4 Modularity and sharing 58.5 Subject area Foundation 69 Mapping a CDIF subject area to a PCTE SDS 79.1 Format of mapping 79.2 Common meta-object properties 7- ii -9.3 Subject a
18、rea 89.4 Meta-entities 89.5 Meta-relationships 99.6 Meta-attributes 109.7 Data types 119.8 Subject area Foundation 1310 Introduction to derived SDSs defined in annexes 1310.1 Aims 1310.2 PCTE modelling language standard 1310.3 Ordering of subject area definitions 1310.4 Ordering of SDS definitions 1
19、310.5 Structure of SDS definitions 14Annex A - SDS CDIF_Foundation 15Annex B - SDS CDIF_Common 17Annex C - SDS CDIF_DataDefinition 21Annex D - SDS CDIF_DataModelling 351ScopeThis ECMA Standard specifies a mapping of CDIF to PCTE or, more specifically, of a CDIF subject area to a PCTESchema Definitio
20、n Set (SDS).The mapping may be applied to standard CDIF subject areas and to CDIF subject areas defined as user extensions,provided they follow the restrictions used in the CDIF subject area standards.PCTE (ECMA-149) is an interface to a set of facilities that forms the basis for constructing enviro
21、nments supportingsystems engineering projects. These facilities are designed particularly to provide an infrastructure for programs whichmay be part of such environments. Such programs, which are used as aids to systems development, are often referred toas tools or CASE tools.CDIF (EIA/IS-107) is an
22、 architecture and facilities for transferring information, often referred to as models, betweenCASE tools, including repositories. The CDIF architecture includes a modelling language, the CDIF meta-meta-model,for defining an integrated meta-model that in turn defines the information models for subje
23、ct areas of systemsengineering. The CDIF architecture also includes a transfer format for transferring models between tools.Application of this mapping to a CDIF subject area generates a derived PCTE SDS that is semantically equivalent tothe CDIF subject area. Such derived SDSs provide a means of ex
24、changing models between CASE tools and a PCTE implementation; a means of realising models defined according to the corresponding CDIF subject areas in a PCTE installation; hence a basis for standard SDSs for systems engineering subject areas.The derived SDSs are not sufficient to define all the prop
25、erties needed for efficient use of the models within a PCTE installation; for the faithful transfer of the models between different PCTE installations.2 Conformance2.1 Conformance of an SDSA PCTE SDS conforms to this ECMA Standard with respect to a given CDIF subject area if, and only if, it contain
26、stype definitions that are derived from the specification for the given CDIF subject area (as defined in the relevantEIA/IS subject area specifications) according to the mapping in clause 9. Such an SDS is referred to as an SDS forthe (given) CDIF subject area.2.2 Conformance of a PCTE toolA PCTE mo
27、del (of a given CDIF subject area) is a collection of objects which are instances of types defined in anSDS, which conforms to this ECMA Standard, for the given subject area. This ECMA Standard does not define howa PCTE model is represented in a PCTE installation.NOTEA PCTE model could, for example,
28、 be represented by a composite object whose components are instances of thetypes defined in a conforming SDS or by a directory object with existence links to instances of the types defined in aconforming SDS.A PCTE tool conforms to this ECMA Standard if and only if it uses an SDS for a given CDIF su
29、bject area to manage a PCTE model of that subject area, and it uses no alternative SDS to model properties of that subject area3 Normative referencesThe following normative documents contain provisions which, through reference in this text, constitute provisions ofthis ECMA Standard. For dated refer
30、ences, subsequent amendments to, or revisions of, any of these publications donot apply. However, parties to agreements based on this ECMA Standard are encouraged to investigate the possibility- 2 -of applying the most recent editions of the normative documents indicated below. For undated reference
31、s, the latestedition of the normative document referred to applies.ECMA-149 Portable Common Tool Environment (PCTE) - Abstract Specification, 4th edition (1997)EIA/IS-107 CDIF / Framework for Modeling and Extensibility, January 1994EIA/IS-111 CDIF - Integrated Meta-model / Foundation Subject Area, J
32、anuary 1994EIA/IS-112 CDIF - Integrated Meta-model / Common Subject Area, December 1995EIA/IS-113 CDIF - Integrated Meta-model / Data Definition Subject Area, May 1996 (draft)EIA/IS-114 CDIF - Integrated Meta-model / Data Modeling Subject Area, December 19964 Terms and definitions4.1 CDIF and PCTE t
33、ermsMost of the technical terms used in this ECMA Standard are CDIF and PCTE terms defined in EIA/IS-107 andECMA-149, respectively. Such terms are qualified by “CDIF“ and “PCTE“, respectively, as necessary to make theintended meaning clear.There are two areas of difficulty with terminology that are
34、inherent in the subject matter. The first is that terms suchas “subject area“ and “meta-object“ in CDIF, “SDS“ and “object type“ in PCTE, are used either in a general,inclusive sense that captures the informal notion, e.g. a subject area with all its contents, the type of an objectincluding its attr
35、ibutes and links, or in a restricted, exclusive sense that is required for technical specification, wherefor example a subject area is separate from the meta-entities etc. that are used in it, an object type is separate fromthe attribute types etc. that may be applied to it. In EIA/IS-107, such term
36、s are used in the restricted sense, exceptoccasionally in the more general discussion (clauses 7 and 8) where the distinction is clear from the context.The second area of difficulty is groups of closely related concepts with conventionally related ways of referring tothem. For example, in CDIF there
37、 are (a) meta-entity, (b) the meta-meta-entity “MetaEntity“, and (c) metaentity (aninstance of “MetaEntity“); in PCTE there are (a) object type in DDL, (b) object type (and type in SDS) in the PCTEFoundation, and (c) object type (and type in SDS) in the SDS “metasds“. For EIA/IS-107, the simplest an
38、d mostreadable form has been chosen, viz terms used in the textual specification of subject areas (e.g. meta-entity) andSDSs (e.g. object type).4.2 Other termsFor the purposes of this ECMA Standard, the terms and definitions given in ECMA-149, EIA/IS-107, EIA/IS-111,EIA/IS-112, EIA/IS-113, EIA/IS-11
39、4 and the following apply.4.2.1 CASE toolA program that is used as an aid to systems development.4.2.2 derived SDSA PCTE SDS generated by application of the mapping defined in this ECMA Standard to a CDIF subject area.4.2.3 model(When used generally) a description of an information system used in sy
40、stem development.4.2.4 PCTE modelSee 2.2.4.2.5 PCTE toolA CASE tool that uses the facilities of a PCTE implementation.4.2.6 SDS for a (given) CDIF subject areaSee 2.1.- 3 -5 Symbols (and abbreviated terms)5.1 NotationsPCTE SDSs are defined using PCTE DDL as defined in annex B of ECMA-149.5.2 Abbrevi
41、ationsThe following abbreviations are used in this ECMA Standard.5.2.1 CDIFCASE Data Interchange Format.5.2.2 DDLData Definition Language.5.2.3 PCTEPortable Common Tool Environment.5.2.4 SDSSchema Definition Set (a PCTE term).6 Outline of the StandardClause 7 states the general principles that are a
42、pplied to define the mapping. Clause 8 discusses the main differencesbetween CDIF and PCTE and how these are resolved in the mapping. The mapping is defined in clause 9. Clause 10introduces some examples of derived SDSs which follow in informative annexes.7 Mapping principlesThis clause defines gene
43、ral principles for deriving PCTE SDSs corresponding to subject areas of the CDIF integratedmeta-model.The following general principles were applied when defining the mapping of CDIF to PCTE.a) The purpose of the mapping is to derive PCTE SDSs corresponding to CDIF subject areas that enable therealis
44、ation in a PCTE installation of models defined according to those subject areas.b) The derived SDSs are not intended to be sufficient for other purposes such as the definition of all the propertiesneeded for efficient use of the models within a PCTE installation nor for the faithful transfer of the
45、models betweendifferent PCTE installations. Thus, for example, the derived SDSs make no use of object contents or most linkcategories.c) The mapping should be capable of deriving valid SDSs for subject areas defined as user extensions, provided theyfollow the restrictions used in the CDIF subject ar
46、ea standards. The mapping cannot resolve any clashes in userextensions that are defined independently and then used together.d) The mapping should be fully determined by rules that can be applied automatically, either by human or bycomputer.e) The mapping should be a total function from CDIF to PCTE
47、, i.e. a mapping of all CDIF concepts to a subset ofPCTE concepts. With the mapping represented as a two-column table, the CDIF column should contain all CDIFconcepts but the PCTE column may omit PCTE concepts that are not used to represent CDIF concepts.f) The mapping should not preclude the additi
48、on of PCTE-implementation-dependent DDL to derived SDSs that maybe required by a conforming PCTE implementation. For example, the mapping might allow additional importationsthat are not defined by EIA/IS-107.g) The mapping should derive a single, unique PCTE SDS from each CDIF subject area, so that
49、a PCTE tool usinginformation defined in a set of CDIF subject areas should only need the corresponding PCTE SDSs in its workingschema. (A possible exception might be for one SDS that is needed for use with any subject area, but this has notproved necessary.)h) The semantics of a derived SDS should, whenever possible, be the same as the semantics of the correspondingsubject area, and should be determined by reference to the standard for that subject area.- 4 -i) The derived PCTE SDSs should have names that distinguish them from SDSs for similar “subject areas“ that arenot derived
