SEBGIS 2005, Agia Napa, Cyprus, October 31 - November 4, 2005 MECOSIG Adapted to the Design of Distributed GIS F. Pasquasy, F. Laplanche, J-C. Sainte &

SEBGIS 2005, Agia Napa, Cyprus, October 31 - November 4, 2005

MECOSIG Adapted to the Design of MECOSIG Adapted to the Design of Distributed GISDistributed GIS

F. Pasquasy, F. Laplanche, J-C. Sainte & J-P. DonnayF. Pasquasy, F. Laplanche, J-C. Sainte & J-P. Donnay

Unit of Geomatics, University of Liège, BelgiumUnit of Geomatics, University of Liège, Belgium

http://www.geo.ulg.ac.behttp://www.geo.ulg.ac.be

SEBGIS 2005, Agia Napa, Cyprus, October 31 - November 4, 2005 2

MECOSIGMECOSIG

A method devoted to GIS design and implementation [published in 1996] considering:

GIS as an Information System (IS) where IS Organization (systemic approach)

Organization as the core of the method The method has been progressively improved (last

decade) Emergence of distributed GIS involved :

reassessment of the methodology new concerns and tools (fitting the requirements of distributed

environments) identified


MECOSIG - Design protocolMECOSIG - Design protocol

Method covering the complete GIS’s lifecycle using specific tools at different abstraction levels

Descriptive to Logical-Physical level...

Design protocol is summarized into a monitoring matrix every cell relates to

specific tools (formalisms, models, prototyping …) semantic concerns (metadata, documentation …)

Main concerns are Organization, Data, Data flows, Processes

MECOSIG suggested to go twice through the monitoring matrix

analysis stage (not anymore taken into account because of redundancy with the descriptive level in conception step)

conception step


MECOSIG - Monitoring MatrixMECOSIG - Monitoring Matrix


Adaptations - Descriptive levelAdaptations - Descriptive level

Group of actors of the organization(s) must be identified Actors have their own:

set of privileges specific use cases

More often a specialization relationship exists between them


Adaptations - Descriptive levelAdaptations - Descriptive level

Concerning processes (in particular crossed processes in distributed GIS), interactions between groups of actors and the System are identified in terms of:

textual descriptions UML use cases

Data are identified according to use cases Data are described in a catalogue and quality must be

analysed Use of standards (ISO 19110 & 19115) is recommended

Further agreements must be achieved in order to incorporate semantic rules in spatial data domain (interoperability requirements …)




Adaptations - Conceptual levelAdaptations - Conceptual level

UML class diagram used to design Data (original formalism proposed in MECOSIG - CONGOO is substituted)

is internationally admitted as standard (System modelling) offers more than only one diagram

design can combine serial of models to depict a context

Specificity of spatial data in UML object’s geometry

a lot of studies [e.g. COMOSIG Workshops ER2004, Bédard & al., 2004] dealt with

stereotypes or tagged values allow to adapt UML topological relationships

concept of topological matrix (originally from CONGOO) is added and adapted

two kinds of topological matrix are available the traditional matrix and the strong one





Every use case is extracted from the descriptive level and detailed using UML activity diagrams

Sequence diagrams are used to conceptualize specific scenarios of activity diagrams




Adaptations - Organizational levelAdaptations - Organizational level

Facing the implementation of a distributed infrastructure, important organisational constraints must be met

missions of all actors should be assessed and possibly redefined

new tasks are introduced in order to guarantee maintenance, permanent working and growth of the

distributed System new data flows are generated and others have to be

adapted data exchange must be performed easily and in a

transparent way for all users access to metadata [ISO standards] - particularly metadata

related to quality (data usability and appraisal of final results) some data / services access can be restricted or subject to

authorization(s)


Adaptations - Organizational levelAdaptations - Organizational level

From these purposes coming up representative’s committees in charge of

coordination tasks formalization can also be introduced to depict their tasks

(UML use cases, activity & sequence diagrams, …)




Adaptations - Logical-Physical levelAdaptations - Logical-Physical level

Roles and tasks of all actors should be clearly specified key is to associate all actors in the new System which will

be set up e.g.:

sensitizing and training sessions to facilitate the understanding of the re-engineered system

possible reallocation of human resources

Constitution of the representative’s committees in charge of coordination tasks

competent and representative of the various departments or organizations

receiving the ability to act decisively Managerial economies and economies of scale could be

achieved Acquisition of common reference data Globalisation of software licenses



A technical study must be completed to guarantee the required degree of interoperability to identify precisely

add-on hardware and software distributed system components systems for cross-relating items of information across multiple

sources

Modelling process is to design objects which must be deployed in a distributed System

e.g. data storage structure (components and deployment UML diagrams)

previous activity and sequence diagrams (conceptual level) are improved

by adding objects dealing with data flows, procedures and processes according to GIS software, tools and DBMS specificities...





Whole of the logical-physical level is integrated into a evolutionary project pilot

SEBGIS 2005, Agia Napa, Cyprus, October 31 - November 4, 2005

Thank you…Thank you…

Q / A ?Q / A ?

http://www.geo.ulg.ac.behttp://www.geo.ulg.ac.be

Documents

SEBGIS 2005, Agia Napa, Cyprus, October 31 - November 4, 2005 MECOSIG Adapted to the Design of Distributed GIS F. Pasquasy, F. Laplanche, J-C. Sainte &