Volvox integrated decision support systems

B. Julien & F. Ouzilleau

Centre de recherche Volvox, Inc., 1210 Sherbrooke St. West,

2nd floor, Montreal, Quebec, H3A 1H6, Canada

Abstract

In recent years, there has been a significant rise in the use of computers for solvingenvironmental problems. The focus has been mostly on the mathematical modelmg of physical, chemical, and biological phenomena and much less attentionhas been paid to the critical issue of properly supporting environmental decision-making processes. These processes generally require the multi-disciplinary anal-ysis and synthesis of large amounts of diversified information. In response tothis important need, the Volvox project aims at providing a computer-based plat-(IEDSS) '̂°P™*°' of integrated environmental decision support systems

Volvox offers an open object-oriented framework where Volvox decisionaids and off-the-shelf specialized software can be easily integrated for build-ing customized IEDSS. A macro language is also defined for controlling andexchanging information between IEDSS modules.

1 Introduction

Over the last two decades, important research and development efforts have beendevoted to the study of environmental processes in order to better understandmodel or predict environmental impacts. These efforts have permitted the devel-opment of elaborate analytical and empirical models capable of tracing changesin ecosystems physical, chemical and biological conditions over time and space

A researchers m environmental sciences have mostly focused on elucidatingand modeling environmental phenomena and have paid much less attention to thefinal use of environmental information in planning and decision-making. Thishas left the field of environmental sciences and engineering with a large numberof disparate and poorly integrated mathematical models.

In order to properly help practitioners in their environmental evaluationand planning tasks, computer-based methods that can assist the overall environ-mental decision-making process must be developed. This requires integratingmathematical models with information management techniques so as to supportenvironmental data acquisition, analysis, and synthesis. For data acquisitionsuch a decision support framework should allow the user to easily access and

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consult relevant documents pertaining to his/her specific activity in the decision-making process. Means to transfer information from spatial and non-spatialdatabases to specialized environmental analysis models should also be provided.In addition, information exchange between models must also be possible in orderto represent and analyze complex processes involving multiple models. Finally,synthesis methods focusing on the explicit comparison and efficient communi-cation of environmental results have to be offered. Impact analysis generallyproduce very large quantities of information which need to be summarized fordecision-making. Without an emphasis on synthesis, environmental studies candegenerate into an indiscriminate data gathering exercise of encyclopedic pro-portion, the end product of which may be difficult to justify on grounds ofenvironmental soundness, social or political acceptability or cost effectiveness[2]. Information management techniques are therefore needed for organizingand communicating the environmental information in an intelligible, concise andlogical way.

One of the principal objectives of the Volvox project is to provide sucha computer-based framework for the development of integrated environmentaldecision support systems (IEDSS). After an overview of the Volvox consortiumand projects, this paper presents the key principles behind the Volvox modelintegration approach. The overall architecture and principal components of theIEDSS development platform are also described. The paper concludes on thebenefits and limits of the Volvox lEDSSs.

2 Overview of the Volvox Project

Volvox is the largest industrial research and development project of its kindin Canada with a total budget of $ 38.5 million (cdn.). The project is led bythe Centre de recherche Volvox (Volvox Research Centre), a consortium of sixleading Canadian firms in the fields of information technology and engineering:CGI Group, a consulting firm in systems integration and telecommunications;Lamtag-Geogester-GVD International, a company specialized in geographicalinformation systems (GIS); S.M. Group, an engineering firm in the field ofremote sensing; Systemes Taarna and Conception Visuelle Synoptech, two com-panies specialized in infographics and 3D modeling and visualisation; and AlexInformatique, a manufacturer of parallel computer hardware and software. Thiswide range of expertise allows the consortium Volvox to cover the broad spec-trum of computer techniques required for assembling integrated decision-supportsystems (IDSS).

The overall objective of the project is two-fold. First, to offer decision-makers and specialists of various domains a computer-based platform equippedwith a comprehensive set of decision aids for the development of IDSSs. Thesecond objective is to provide programmers with a state-of-the-art generic toolkitfor building computer applications. The two objectives are complementary sincethe toolkit is used in the design of the platform and decision aids for developingIDSS applications. This paper focuses on the first objective and describes theIDSS development platform and decision aids in the context of environmentalstudies.

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Six IDSSs are currently being developed by the Volvox Research Centre. Asystem for the environmental evaluation of electric transmission lines and stationswas the first IEDSS built with the Volvox development platform. Examples takenfrom this operational IEDSS are described in the paper to illustrate the functionsand integration capabilities of the platform.

3 Integration Approach

3.1 Guiding Principles

Environmental decision-making problems can be classified among the most com-plex decision problems. The complexity arises from the combination of severalcharacteristics of environmental studies:

• Multiple data sources. Large amounts of information must often be gath-ered for environmental studies. This information is often disseminated andvery diverse in its nature (e.g., dynamic, spatial, uncertain, qualitative) andform (e.g., databases, texts, maps, pictures, tables).

• Multiple models. The analysis and synthesis of the environmental infor-mation generally requires the use and integration of a wide range of spe-cialized empirical and analytical models (e.g., numerical/symbolic models,stochastic/deterministic models).

• Multiple specialists. Environmental decision-making is a multi-disciplinaryeffort performed by many specialists (e.g., managers, engineers, biologists)working in groups on different related sub-tasks.

From these problem characteristics, four key requirements have been setfor the design of an IEDSS development platform: accessibility, adaptability,reusability, and sharing. The accessibility criterion requires that data and modelscan be easily consulted, used and stored. For this purpose, a number of tools havebeen developed for accessing databases and for finding and editing various doc-uments. The development platform is also designed based on the object-orientedparadigm so that data and related procedures can be encapsulated together. Inthis way, the access to the information also provides direct access to the meansnecessary for viewing and modifying the information. For instance, the selectionof a map or a text automatically opens the GIS and text editor assigned to thedocuments. This transparent link between data and its related procedures greatlysimplifies the use of an IEDSS.

Adaptability is the second key requirement for IEDSS. The users must beable to easily build new IEDSS or modify existing ones for their particular needs.To fulfill this requirement, the development platform offers basic building blocksfrom which IEDSS can be assembled. The building blocks, also referred toas objects, consist of specialized decision aids such as a multicriteria decision-making model, a GIS, etc. The terms model, tool, and decision aid are usedinterchangeably to designate any software assisting decision-making. The def-inition context is very large since a word processor is considered as a decision

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aid. The IEDSS development platform components are described in more detailin the next section.

The IEDSS basic objects are assembled together by establishing links be-tween them. These user-defined source/receptor links act as constraints where thesource object can modify the state of the receptor object. With these constraintsthe user can automate parts of the decision-making process. For instance, inthe IEDSS for environmental evaluation, a user can define links between a mapobject and a multicriteria object so that modifications of some of the entities onthe map can have repercussions on the values contained in the multicriteria de-cision table. The constraints between IEDSS objects are specified using a scriptlanguage.

The wide diversity of environmental tasks and models makes it impossibleto determine an exhaustive set of useful 1EDSS objects. Even if such a setexisted, it would be naive and unrealistic to expect all users to only rely onthese decision aids and abandon computer tools that they trust and are familiarwith. For this reason, the development platform offers a limited set of decisionaids that users can expand by adding their own tools. Such an open IEDSSdevelopment framework allows the integration of additional models as long asthese models respect recent industry integration standards such as OLE (ObjectLinking and Embedding) [3]. Several commercial software such as text andspreadsheet editors (e.g., Microsoft Word, Microsoft Excel) can already be easilyincorporated in lEDSSs and constraints can be established between them andother components of the development platform.

The development platform also puts the emphasis on reusability. Once thedecision aids have been selected and organized properly for a specific envi-ronmental study and all the relevant constraints have been defined, the resultingIEDSS can be stored and reused for other similar tasks. Moreover, the modularityprovided by the object-oriented approach allows specific parts of existing IEDSSto be extracted and customized for new applications (i.e., an IEDSS composedof other lEDSSs).

Finally, sharing is another essential feature for supporting any multi-disci-plinary task. Since groups of specialists are involved in most environmentalstudies, they have to be able to share information among them and betweengroups. The development platform supports workgroups by allowing decisionaids to be shared through a computer network. As a result, different specialistscan work simultaneously on different parts of the same IEDSS. For example, itis possible for a GIS specialist to complete an analysis and have the updated mapdirectly available to all the other specialists who need it.

Depending on the complexity of the decision process, an IEDSS can involvea very large number of decision aids. In order to focus on specific aspects of anenvironmental study, the specialist can define with the platform several views ofa single IEDSS. A view allows the users to access from the assembled IEDSSobjects only the ones that they are interested in working with. For instance, a GISspecialist can define a view where only the maps and other related documents areloaded. In summary, the IEDSS development platform offers an object-orientedframework for the integration of models into a collection of decision aids whichcan be easily used by many specialists simultaneously. After this brief overviewof the key design features of the IEDSS development platform, the next sectionpresents the overall architecture of the platform.

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3.2 Overall Architecture

The overall objective of an IEDSS is to improve the quality and efficiency ofenvironmental decision-making by providing users with a user-friendly, flexibleand integrated working environment. For this purpose, the IEDSS developmentplatform offers a set of specialized decision aids and commonly used tools suchas a word processor and a spreadsheet editor. As mentioned previously all thesemodels are represented as objects that can be linked and shared. The overallapproach is document-centric since any piece of information (e.g. maps texts) isconsidered as an object document that can be directly viewed and modified. AnIEDSS is a component software that is made of reusable piece of software (i eobjects) assembled together using the development platform. The developmentplatform can be viewed as a suite of decision aids where the added value emergesfrom the interoperability between the decision aids.

Tcn Volvox platform provides four specialized decision aids for buildinglEDSSs: dfCiMOMpmc&M manager; /;Wr%m; GAS; and a^an'a/mw/n-cn^noMakcmoM-matrng f̂ fem. The decision process manager permits a hierarchicaldecomposition of a decision path into specific activities to which related softwaretools can be linked. The user can specify for each activity of the decisionprocess graph, the documents and persons needed to execute the task. The outputdocuments of an activity (e.g., maps) are opened and modified in order to performthe task (e.g., producing an inventory map of environmental elements). Theoutput documents of an activity can also be specified as pre-requisite documentsfor a subsequent activity.

The librarian provides support for the search and retrieval of different typesof local and remote documents. The documents are selected by finding user-provided key words in their contents or in their general attributes (e.g searchby author, title). Documents can also be indexed by specific domain attributesFor instance, in the IEDSS for environmental impact assessment, all relevantdocuments were also indexed by the name of the environmental elements theydiscuss. The documents retrieved can then be inserted in the collection of IEDSSobjects. They can also be linked or embedded into other documents (e.g a textdocument within a spreadsheet or attached to an activity of the decision processmanager).

The GIS manages vector and raster maps and allows the visualisation andanalysis of spatial environmental information. The GIS has the unique featureof allowing the assignment of data as well as documents to geographical entitieson a map. The map can therefore be used for spatially referencing documentsBy selecting an entity on a map, the user can directly consult and modify anydocument (e.g., spreadsheets, texts, pictures) linked to the entity. The mapbecomes a multimedia document allowing a spatially referenced access to awide range of information and models. A 3D animation system will also beincorporated in the GIS. The 3D viewing system will permit the visual impactassessment of projects and the visualisation of complex numerical simulationresults.

The development platform also includes a spatial multi-criterion decision-makmg system for the explicit comparison of different solutions to environmentalproblems. The decision model can handle qualitative as well as quantitative eval-uations with different ranking algorithms available (e.g., weighted sum, ELEC-TRE). Criteria with values spatially distributed can also be analyzed.

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Desktopof IDSSUser 2 ^ ^

View 1

Server Site Client Sites

Figure 1: IEDSS Development Platform Architecture

Before directly using these tools and other in-house or commercial decisionaids (e.g., mathematical models, spreadsheets), the user has to follow three basicIEDSS development stages. First, the decision process must be defined byidentifying and organizing the sequence of activities needed to execute the task.Once the process is established, the information needed (inputs) and produced(outputs) by each activity should be defined by the IEDSS developer. Finally,the techniques and methods to perform each activity and produce the requiredinformation have to be determined. With all the IEDSS objects identified, thedevelopment platform can then be used for building the IEDSS.

As shown on Figure 1, the IEDSS development platform is implemented asa client/server architecture where all the IEDSS objects identified are centralizedon a server and shared between the IEDSS users. Each user has different accessrights to the IEDSS objects. The IEDSS object server manages the user accessrights and resolves conflicts between users who want to edit the same document.More importantly, the server updates the collection of objects by adding orreplacing objects that are created or modified by the IEDSS users.

Each IEDSS user access the object server transparently through an IEDSSdesktop application. The main function of the desktop is to provide a uniqueand efficient interface between the server and the user views. As mentionedpreviously, a view allows users to access only the subset of the assembled IEDSSobjects that they are interested in working with. The users can define multipleviews on their desktop (see Figure 1).

Each view is organized as a stack of documents with tabs describing eachdocument. The user can rely on different selectors to determine the content of aparticular view. These selectors are object indexes that the user can combine toretrieve specific documents managed by the IEDSS object server. In the IEDSSfor environmental evaluation, a selector defining the table of contents of the finalreport was created and used by the project team members to organize all the

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Computer Techniques in Environmental Studies 231

View showing all thedocuments of type map

assigned to chapiter 2.1 inthe table of contents

Document Type SelectorTable of Contents Selector

fjchier /Edition Selecteurs fie/nion Fjche Lien carte Fenetre AideteurTYPES DOCUMEN

-CaTEXTESj-DWord 6.0 Text'-̂ WordPerfect 5.2 Text

2-lnventaire prelH±]3 0-lnventaire detaille4 0-Clossif elementHy^B.O-Variantes traces

J View showing the documents (only one in this IP[case) linked to the map showed in the upper view!

Figure 2: IEDSS User Interface

documents produced for the environmental impact assessment project. Figure 2illustrates the IEDSS desktop of a user where two views have been defined usingdifferent selectors. The first view (first half of Figure 2) groups all the mapsassigned to chapter 2.1 of the evaluation report. This view was produced bycombining a selector types of document for accessing the maps and a selectortable of content for referring to chapter 2.1.

Two principal categories of links can be established between IEDSS objects:multimedia and constraint. The multimedia links allow users to navigate moreefficiently through the various documents. For instance, the second view inFigure 2 illustrates a map link selector that was used to collect all the documentsattached to a map in the first view. The new view presents the single textdocument that was assigned to a study zone depicted on the map. The documentexplains how the limits of the study zone were determined.

The IEDSS developers can also program constraint links that can performspecific actions such as transferring data between objects. The actions are spec-ified with the Basic programming language using the methods and properties ofthe objects linked together. The scripts defining each constraint are stored by

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the IEDSS desktop on the object server. They can be activated manually by theuser or fired automatically by the desktop depending on the trigger conditions.An example of this feature is the constraint between the map and spreadsheetobjects in the IEDSS for environmental evaluation. The constraint automaticallytransfers the length attribute value of an electric transmission line described on aVolvox map object to a Microsoft Excel spreadsheet for the estimation of its con-struction cost. Using this kind of constraint, the user can quickly perform "whatif" analysis by simply changing the path of the transmission line on the map andhave the resulting new cost figures automatically calculated in the spreadsheettable.

4 Conclusions

Practical and useful computer-aided environmental evaluation and planning willonly be possible once methods to support the full decision-making cycle areavailable. This is the motivation behind the Volvox IEDSS development plat-form. The platform offers a state-of-the-art object-oriented framework for theintegration of decision aids that can improve the consistency, quality and effi-ciency of environmental studies. The lEDSSs can be viewed as computerizedreports acting as repositories of linked documents that can be consulted and mod-ified by many users simultaneously. The open architecture of the Volvox IEDSSdevelopment platform was designed to ease the implementation of systems thatrequire: models of the decision process; facilities for the search, acquisition,organization, sharing and storage of the information; and tools for informationanalysis, interpretation, and communication.

The development of an IEDSS does not guarantee the quality of the decision-making. The approach is descriptive and therefore does not impose a norm onwhat constitutes a bad or good decision analysis and synthesis. Hence, the dangeralways exists that such a system will be misused by users providing incorrectdecision process structure or information. The 1EDSS developer must also becareful in the definition of the constraints between decision aids so as to keepthe decision process explicit and tractable. Nevertheless, the Volvox IEDSSdevelopment platform provides specialists involved in environmental studiesand decision-making with a powerful and flexible computer-based frameworkfor assisting their work.

References

[1] S. E. Jorgensen, editor. Application of Ecological Modelling in Environmen-tal Management, Part A. Elsevier Scientific Publishing Company, Amster-dam, Netherlands, 1983.

[2] N. Lee. The future development of environmental impact assessment. Jour-nal of Environmental Management, 14:71-90, 1982.

[3] M. Miller. Getting it together. PC Magazine, pages 110-138, February 1994.

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