Tool Interoperability using iStarML

Abstract

iStarML is an XML-based format for enabling interoperability among i* tools. Its main design focus was to support data interchange even when involved tools implement different i* variants. In this paper, we present a summary of the format, we briefly describe the ccistarml Java library, and we show an application of it. We finally summarize the requirements for representing new i* concepts in order to generate a revised version of iStarML.

Keywords

• i* Framework
• iStar
• iStarML
• interoperability

2 iStarML Computational Support

In [ 2 ] we offer a set of basic XML specifications. First, we provide an iStarML specification using an XSD definition. This specification is the most used specification types for XML files. A clear advantage is that XML processors can parse XML files using XSD definitions which means that iStarML parsers can be implemented taking public XML processors and this XSD definition. However, this definition has some limitations derived from the XSD grammar, e.g., a dependency between attributes cannot be represented on XSD specifications. Therefore, although less popular but more accurate, we have provided a Schematron [ 3 ] set of rules for iStarML syntax verification.

In addition to these parsing proposals, we have developed a Java package for handling iStarML files. We have called it ccistarml package. The several classes inside this package allow creating, reading and modifying iStarML files. Each of these classes is explained and illustrated using simple examples in the ccistarml tutorial [ 4 ]. The code in Fig. 2 illustrates how an iStarML file can be loaded, parsed, modified by adding a new actor, and saved.

ccistarmlFile f = new ccistarmlFile(); f.loadFile(“sample01.istarml.xml”); f.istarmlParser(); if (!f.hasErrors()) { ccistarmlContent content = f.mainTagStructure(); content.add_actor(“Tutor”); f.saveFile(); } Since iStarML was proposed, we have developed different interoperability scenarios and applications: (1) storing diagrams in the HiME hierarchical i* tool [ 5 ]; (2) exporting and importing iStarML in the jUCMNav GRL tool including interoperability proofs [ 6 ]; (3) translating files from OME3 tool to iStarML file by using a Java applet [ 7 ]. About taking advantage of XML representation of iStarML we have (4) exemplified the use of XPath for metric calculations [ 1 ]; (5) used XSLT for transforming iStarML files into Prolog clauses [ 8 ]; and (6) used XQuery for quality assurance of i* models [ 9 ]. We also mention the use of iStarML as the basis for formulating a supermetamodel coordinating model interoperability in a semanticaware scenario [ 10 ].

4 Conclusions and Future Work

In this paper we have presented iStarML 1.0 as an interoperability facility for i* tools. Our proposal considers the existence of i* variants and hence, a polysemantic scenario. We have shown its structure, some computational support and different scenarios illustrating both the feasibility of reaching interoperability and the advantages of having a XML representation for i* models.

It is our position that iStarML is a solid proposal, but its dissemination and usage depends on including most of the current and future representational requirements of the i* community, which can be reached only by constituting a wide working group motivated to generate iStarML 2.0.

Next steps on iStarML include interoperability tests of the two existing possibilities of graphic representations: iStarML’s graphic elements and the nested structures proposed in iStarML for including SVG tags [ 11 ]. Here for example we have the challenge of handling the graphical proposal for representing inherited intentional elements from [ 12 ]. Finally, we are also planning to improve the current representational capabilities of iStarML extending it to handle concepts such as modules [ 13 ] and similar tags enabling Computer Supporting Collaborative Engineering.

Acknowledgments

This work has been supported by the Spanish project TIN2010-19130-c02-01.

References

1. Cares , C. , Franch , X. , Perini , A. , Susi , A. : Towards Interoperability of i* Models Using iStarML . Computer Standards & Interfaces , 33 ( 1 ), 69 - 79 ( 2011 )

2. iStarML site, http://www.essi.upc.edu/~gessi/iStarML

3. Jelliffe , R. : The Schematron Assertion Language 1 .6, http://xml.ascc.net/resource/ schematron/Schematron2000.html ( 2002 )

4. Cares , C. : ccistarml: A Java Package for Handling iStarML files , http://www.essi.upc.edu/ ~ccares/papers/ccistarml_v0.6.pdf

5. HiME site, http://www.upc.edu/gessi/HIME/

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7. OME3 to iStarML Converter, http://www.essi.upc.edu/~gessi/iStarML/ometoistarmlremoto/online_tools.html

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11. Scalable Vector Graphics (SVG) site , http://www.w3.org/Graphics/SVG/

12. López , L. , Franch , X. , Marco , J.: Defining Inheritance in i* at the Level of SR Intentional Elements . In Proc. of the 3rd International i* Workshop (iSTAR08) , February 11-12 , Recife, Brazil, pp. 71 - 74 ( 2008 ).

13. Franch , X. : Incorporating Modules into the i* Framework , LNCS , 6051 , pp 439 - 545 ( 2007 )