cora – common reference architecture · cora – common reference architecture monica scannapieco...
TRANSCRIPT
Eurostat
CORA –COmmonReferenceArchitecture
Monica Scannapieco Istat
Carlo Vaccari
Università di Camerino
Antonino Virgillito
Istat
Eurostat
Outline
• Introduction (90 mins)
• CORE Design (60 mins)
• CORE Architectural Components (90 mins)
• Illustration of CORE Platform (135 mins)
• Case studies (90 mins)
• CORE Follow-up (60 mins)
Eurostat
Introduction
Eurostat
CORE Generalities
• Principal Outcome: Environment for the definitionand execution of standard statistical processes
– Definition of a process in terms of availableservices
– Execution of the composed workflow
Eurostat
CORE Generalities
Service Repository
Process
View
“Plug and play” approach to process execution
Eurostat
CORE Generalities
“Plug and play” approach to process execution
Service Repository
Process View Data View
Eurostat
Why CORE?
STOP
Allocation(MAUSS – R)
Selection(SAS Script)
Estimation(ReGenesees)
START
Eurostat
Why CORE?
STOP
Allocation(MAUSS – R)
Selection(SAS Script)
Estimation(ReGenesees)
START
Eurostat
Why CORE?
STOP
Allocation(MAUSS – R)
Selection(SAS Script)
Estimation(ReGenesees)
START
TechnologicalHeterogeneity
• Different technologies
• Different formats• …
Eurostat
Why CORE?
STOP
Allocation(MAUSS – R)
Selection(SAS Script)
Estimation(ReGenesees)
START
TechnologicalHeterogeneity
• Different technologies
• Different formats• …
DataHeterogeneity
• Different names for variables
• Variables as combinations of other variables
• ...
Eurostat
Why CORE?
• Technological heterogeneity can be solved by
solutions available on the market
CORE permits to solve both technological and data
heterogeneity in a single environment
Eurostat
CORE Vision
1. Abstract services: well-defined, technology-independentfunctionalities implemented by different IT tools;
2. Statistical process: workflow defined in terms of availableservices;
3. Data model: standardization of the semantics/format ofservices data, i.e. definition of the domain entities involved asinput/output between services.
Eurostat
CORE Vision
1. Abstract services: well-defined, technology-independent functionalities implemented by IT tools
Allocation
Selection
Estimation
(MAUSS – R) (ReGenesees)
(SAS Script)
Eurostat
CORE Vision
3. Data model: standardization of the semantics/format of services data
Allocation
Selection
(MAUSS – R)
(SAS Script)
<schema name="DEMO_DD">
<entity name="SamplePlan">
<property name="VAR"/>
<property name="SIZE"/>
. . .
</entity>
</schema>
3.1 Domain descriptor (DD)
3.2 Mapping to/from DD
DD
Eurostat
CORE Design Tasks - 1
• Design of services
• Definition of integration APIs (IAPIs)
• Data conversion from/to CORA model to/fromtool specific format
• Graphical front ends for designing schemas and mappings
Eurostat
CORE Design Tasks - 2
• Design of processes
• How to define and execute processes withinCORE
• Modelling language
• Execution
• Visual interfaces design
• Design of a service repository
Eurostat
CORE Design Tasks - 3
• Design of exchanged data
• Definition of data models and formats (plainXML/XSD, SDMX…) to be used for data exchanges
• Definition of metadata necessary for processexecution
• SDMX Relationships
Eurostat
CORE Design
Eurostat
CORE Design: Services
• Abstract services: specify a well-definedfunctionality in a technology-independentway
• An abstract service can be implementedby one or more concrete services, i.e. IT tools
• Examples: sample allocation, record linkage, estimates and errorscomputation, etc.
Eurostat
CORE Design: Services
• GSBPM classification
• Documentation purpose
• Provided that a CORE service can be linked to IT tools, GSBPM tagging enables the performance of a search e.g. retrieving“all the IT tools implementing the 5.4 Impute
subprocess of GSBPM proposal”
Eurostat
CORE Design: Services
• Service inputs and outputs
• Specified by logical names
• Characterized with respect to their “role” in data exchangeNon-CORE: if they are not provided by/to otherservices of the process, but are only “local” to a specific service
CORE: they are passed by/to other services and hencethey do need to undergo CORE transformations
Eurostat
CORE Design: Data and Metadata
• They are specified as service inputs and outputs
• Logical names link them to previously specifiedservices
• Non-CORE data only need the file system pathwhere they can be retrieved
Eurostat
CORE Design: CORE Data
• The specification of CORE data is provided by 3 elements:
• Domain descriptor
• CORE data model
• Mapping model
Eurostat
Domain Descriptor: Model
• Entity
• Like “entities” in Entity Relationships
• Entity properties
• Like “attributes” in Entity Relationships
• Very simple (meta-)model
Eurostat
Domain Descriptor: Example
<schema name="DEMO_Domain_Descriptor">
<entity name="SamplePlan">
<property name="STRATIFICATION_VAR"/>
<property name="STRATUM_SAMPLE_SIZE"/>
<property name="STRATUM_POPULATION_SIZE"/>
</entity>
<entity name="Enterprise">
<property name="IDENTIFIER"/>
<property name="STRATIFICATION_VAR"/>
<property name="WEIGHT"/>
<property name="SAMPLING_FRACTION"/>
<property name="ENTERPRISE_FLAG"/>
<property name="EMPLOYEES_NUM"/>
<property name="VALUE_ADDED"/>
<property name="AREA"/>
</entity>
</schema>
Eurostat
Domain Descriptor Role
• Role of the Domain Descriptor (DD): fromservice-to-service data mapping to service-to-global data mapping
Eurostat
CORE Data Model: Role
• Specified once and valid for all processes
• Extensible, i.e. core tag, data set kind, column kind can be modified
• Adds more semantics to data
• Example of usage: mapping to othermodels
Eurostat
CORE Data Model
• Rectangular data set
• CORE tag:
• Data set level (mandatory)
• Column level (optional)
• Rows level (optional)
• Data set kind
• Column kind
Eurostat
CORE Data Model Role
• Specified once and valid for all processes
• Extensible, i.e. core tag, data set kind, column kind can be modified
• Adds more semantics to data
• Example of usage: mapping to othermodels
Eurostat
Mapping Model
• Rectangular data assumption
• Mapping is intended to be specified with respect to Domain
Descriptor
• Columns are to be mapped to properties of an entity
• It contains the specification of how CORE data model
concepts are associated to data
Eurostat
CORE Logical Architecture
Eurostat
CORE GUIs
• Process design
• Ad-hoc customization of an existing tool (Oryx)
• Service data flow
• Service design
• Set of interfaces for the definition of services and
related data flow
• Data design
• Set of interfaces for the specification of domain
descriptors and mapping files
Eurostat
Use Case Specification
• CORE (Principal) Users
33
Eurostat
Use Case Specification: Tool Management
34
Eurostat
Use Case Specification: Service Management
35
Show Tools' List
Add Service
Modify Service
Delete Service
«uses»
Show Services' List
Statistical User Service Management«uses»
«uses»
«uses»
«uses»
«uses»
Select Service
SelectTool
«uses»
Eurostat
Use Case Specification: Process
36
Eurostat
Process design: Oryx
• Oryx is an academic open source frameworkfor graphical process modeling
• Based on web technology
• Extensible via a plugin mechanism and new stencil sets
• Supports BPMN and other processmodeling languages
• Programming language Javascript and Java, internal data format based on RDF
Eurostat
Stencil Set
• Set of graphical objects and rules that specify how to relate those graphical objects to others
• Additional properties that can later be used by other applications or Oryx extensions (e.g. setting element colors and visibility)
• Can be used to build process models
Eurostat
The CORE Stencil Set
• Graphical representation of CORE processes
• Easy-to-use editor (desktop feeling)
• Easy-to-extend source (JSON)
• Defined from BPMN
• Guarantees complete BPMN compliance
Eurostat
Integration APIs
• Purpose: wrapping a tool by a CORE
service
• Translates inputs and outputs of the tool in a
completely transparent and automatic way
Eurostat
Repository
• Processes and their instances
• Services with their GSBPM and CORE classifications
• Tools and their runtime features
• Data with their logical classification within CORE processes
Eurostat
Database design: Overview
42
Eurostat
Database Design: Principal Entities
43
• Service & Tool
Eurostat
Database Design: Principal Entities
-id
-name
-GSBPMtag
-coretag
-version
-namespace
service
-id
-name
-definition
process
0..*
0..*
44
• Service & Process
Eurostat
Database Design: Principal Entities
45
• Operational Data
Eurostat
Process Engine
• Official statistics processes can be viewed from two
perspectives:
• Functional: they are data-oriented, reflecting a common
feature of scientific workflows
• Organizational: they are workflow-oriented, have the
complexity of real production lines, with the need for
harmonizing the work of different actors
Eurostat
Process Engine
• Hence our process engine has two layers …
DATA FLOW CONTROL SYSTEM
WF ENGINE
Complex control flows
� Syncronizing constructs, cycles,
conditions, etc.
� E.g.: Interactive multi-user
editing imputation
Simple control flows
� Sequence of tasks is composed
by connecting the output of one
task to the input of another
� Data intensive operations
Eurostat
Worflow Engine Selection Process
• CORE workpackage (WP$) led by INSEE
• Business Process Management (BPM) platforms:
• Bonita (http://www.bonitasoft.com/)
• Activiti (http://www.Activiti.org/)
• ActiveVOS (http://www.activevos.com/)
Eurostat
Worflow Engine Selection Process
Eurostat
SDMX Relationships
• Both propose an information model
• CORE information model
– takes explicitly process dimension into account
– Data dimension spanning over the whole statistical process
• SDMX information model
– focused on data exchange (though processes are also considered)
Eurostat
SDMX Relationships
• CORE information model
– Deals with both microdata and macrodata
• SDMX information model
– Mainly deals with macrodata
Eurostat
SDMX Relationships
1. Can we use SDMX for micro and macro data exchanges in a CORE process?
– Need for mapping of information models
2. What about metadata?
– CORE: Data and metadata managed at the same way
– SDMX: distinction between structural metadata and reference metadata. Possibility of having domain knowledge codified through concepts
Eurostat
SDMX Relationships
• Choices and steps:
• Conversion from CORE XML to CSV in order to use SDMX conversion tools
• Starting from the CORE file structure it was created a SDMX DSD (Data Structure Definition)
• SDMX data format : cross-sectional
• Once prepared the DSD, we proceeded to convert the CORE file using the SDMX Converter tool
Eurostat
SDMX Relationships
• CORE-to-SDMX Conversion Proof-of-Concept
• Setting:
• Italian Time-Use Survey
• Data Structure Wizard and the SDMX Converter
• Compute Estimates and Sampling Errors” (as the aggregated data dissemination phase)
• Choices and steps:
• Conversion from CORE XML to CSV in order to use SDMX conversion tools
• Starting from the CORE file structure it was created a SDMX DSD (Data Structure Definition)
Eurostat
SDMX Relationships
• The experiment has shown the feasibility of the conversion to SDMX format of a data file obtained as a CORE output
• Not automated conversion:
• Manual mapping of the CORE output’s fields to the dimensions and attributes of the SDMX DSD
• SDMX does not manage more than measure, it was necessary the verticalization of the CORE output file in order to convert it to the SDMX cross sectional
Eurostat
Architecture Deployment
• Web-based architectured centered on a
centralized component
– CORE Environment
• Different CORE deployments can co-exist
– Intra- or Inter- organization
• Services can be remotely executed
– Support is needed in the form of a
distibuted component for tool execution
and data transfer
Eurostat
Types of service runtime
• Batch
– Tool executed by a command line call
– Can be automated
• Interactive
– User interact with the tool through a tool-provided GUI
– Cannot be automated
• Web service
– No tool – procedure distributed on a web service actived
by a programming language call
– Can be automated
Eurostat
CORE Technical Architecture
GUI Definition Repository
Integration APIs
Process Engine
Runtime
CORE Environment
Web service client
Remote activation
Runtime
Runtime agent
Batch-Interactive runtime
Web service runtime
Web container
Run on the machine on which the tool is deployed.Is responsible for: -Preparing the input -Gathering the output-Activating the tool
Eurostat
CORE Technical Architecture
GUI Definition Repository
Integration APIs
Process Engine
Runtime
CORE Environment
Web service client
Remote activation
Runtime
Runtime agent
Batch-Interactive runtime
The process enginesignals a service must be executed
Eurostat
CORE Technical Architecture
GUI Definition Repository
Integration APIs
Process Engine
Runtime
CORE Environment
Web service client
Remote activation
Runtime
Runtime agent
Batch-Interactive runtime
Service definition isextracted from the repository, as well asthe required datasetsand the correspondingmappings
Eurostat
CORE Technical Architecture
GUI Definition Repository
Integration APIs
Process Engine
Runtime
CORE Environment
Web service client
Remote activation
Runtime
Runtime agent
Batch-Interactive runtime
Datasets are convertedaccording to the mapping
Eurostat
CORE Technical Architecture
GUI Definition Repository
Integration APIs
Process Engine
Runtime
CORE Environment
Web service client
Remote activation
Runtime
Runtime agent
Batch-Interactive runtime
Converted datasets are transferred to the remote runtime
Eurostat
CORE Technical Architecture
GUI Definition Repository
Integration APIs
Process Engine
Runtime
CORE Environment
Web service client
Remote activation
Runtime
Runtime agent
Batch-Interactive runtime
The tool is activated by the runtime agent
Eurostat
CORE Technical Architecture
GUI Definition Repository
Integration APIs
Process Engine
Runtime
CORE Environment
Web service client
Remote activation
Runtime
Runtime agent
Batch-Interactive runtime
The output datasets are gathered and sent back to the CORE environment
Eurostat
CORE Technical Architecture
GUI Definition Repository
Integration APIs
Process Engine
Runtime
CORE Environment
Web service client
Remote activation
Runtime
Runtime agent
Batch-Interactive runtime
Datasets are convertedback to CORE format according to the mapping
Eurostat
CORE Technical Architecture
GUI Definition Repository
Integration APIs
Process Engine
Runtime
CORE Environment
Web service client
Remote activation
Runtime
Runtime agent
Batch-Interactive runtime
Converted datasets are stored in the repository
Eurostat
CORE Technical Architecture
GUI Definition Repository
Integration APIs
Process Engine
Runtime
CORE Environment
Web service client
Remote activation
Runtime
Runtime agent
Batch-Interactive runtime
The process continues its execution
Eurostat
Scenario 1
• Remote execution command line/GUI
– Physical layers: CORE env, Service
– AGENT
Eurostat
Scenario 2
• Remote execution web service
– Physical layers: CORE env, Service
Eurostat
CORE Scenario
Eurostat
Why a Process Scenario?
• Helps to clarify ideas and to asses their feasibility
• Forces to make newly proposed solutions concrete
• Can/will be used as empirical test-bed during the whole implementation cycle of the CORE environment
71
Eurostat
How did we build the Scenario?
• Rationale for our Scenario:
• Naturality: involves typical processing steps
performed by NSIs for sample surveys
• Minimality: very easy workflow (no
conditionals, nor cycles), can be run without a
Workflow Engine
• Appropriateness: incorporates as muchheterogeneity as possible: heterogeneity isprecisely what CORE must be able to get rid of
72
Eurostat
Spreading Heterogeneity over the
Scenario
• The Scenario incorporates both:
• Data Heterogeneity
Via data exchanged by CORE services belonging to the scenario process
• Technological Heterogeneity
Via IT tools implementing scenario sub-processes
73
Eurostat
Data Heterogeneity
• The Scenario entails different levels of data
heterogeneity:
• Format Heterogeneity: CSV files, relational DB tables, SDMX XML files involved
• Statistical Heterogeneity: both Micro and Aggregated Data involved
• “Model” Heterogeneity: some data refer to ordinary real-world concepts (e.g. enterprise, individual, …), some other to concepts arising from the statistical domain (e.g. stratum, variance, sampling weight, …)
74
Eurostat
Technological Heterogeneity
• The Scenario requires to wrap inside
CORE-compliant services very different IT
tools:
• simple SQL statements executed on a relational DB
• batch jobs based on SAS or R scripts
• full-fledged R-based systems requiring a human-computer interaction through a GUI layer
75
Eurostat
The Scenario at a glance
76
START
ComputeStrata
Statistics
Allocate the
Sample
Selectthe
Sample
Compute Estimates and Sampling Errors
CalibrateSurvey Data
CollectSurvey Data
Check and Correct
Survey Data
Store Estimatesand Sampling
Errors
Convert to
SDMX
STOP
ALLOCATION
ESTIMATION
Eurostat
Sample Allocation Subprocess
• Overall Goal: determine the minimum
number of units to be sampled inside
each stratum, when lower bounds are
imposed on the expected level of
precision of the estimates the survey
has to deliver
• Two statistical services are needed:
• Compute Strata Statistics
• Allocate the Sample
77
START
Compute
Strata Statistics
Allocate the Sample
AL
LO
CA
TIO
N
START
Compute
Strata Statistics
Allocate the Sample
AL
LO
CA
TIO
N
Eurostat
Compute Strata Statistics
Service• Goal: compute, for each stratum,
the population mean and standard deviation of a set of auxiliary variables
• IT tool: a simple SQL aggregated query with a group-by clause• NSIs usually maintain their sampling frame(s) as Relational DB tables
• Integration API: must support Relational/CORE transformations
• CORA tag: “Statistics”
78
START
ComputeStrata Statistics
Allocate the Sample
AL
LO
CA
TIO
N
START
ComputeStrata Statistics
Allocate the Sample
AL
LO
CA
TIO
N
Eurostat
Allocate the Sample Service
• Goal: solve a constrained
optimization problem to find and
return the optimal sample
allocation across strata
• IT tool: Istat MAUSS-R system
• implemented in R and Java, can be run either in batch mode or interactively via a GUI
• Integration API: must support
CSV/CORE transformations
• MAUSS handles I/O via CSV files
• CORA tag: “Statistics”
79
START
Compute
Strata Statistics
Allocate the Sample
AL
LO
CA
TIO
N
START
Compute
Strata Statistics
Allocate the Sample
AL
LO
CA
TIO
N
Eurostat
Sample Selection Subprocess
• Goal: draw a stratified random sample of units from the sampling frame, according to the previously computed optimal allocation
• IT tool: a simple SAS script to be executed in batch mode
• Integration API: CSV/CORE transformation• SAS datasets have proprietary, closed format ���� we’ll not support direct SAS/CORE conversions
• CORA tag: “Population”• output stores the identifiers of the units to be later surveyed + basic information needed to contact them
80
Selectthe Sample
Selectthe Sample
Eurostat
Estimation Subprocess
• Overall Goal: compute the
estimates the survey must
deliver, and asses their
precision as well
• Two statistical services are
needed:
• Calibrate Survey Data
• Compute Estimates
and Sampling Errors81
Compute Estimates
and Sampling Errors
Calibrate
Survey Data
ES
TIM
AT
IONCompute Estimates
and Sampling Errors
Calibrate
Survey Data
ES
TIM
AT
ION
Eurostat
Calibrate Survey Data Service
• Goal: provide a new set of weights (the “calibrated weights”) to be used for estimation purposes
• IT tool: Istat ReGeneseessystem• implemented in R, can be run either in batch mode or interactively via a GUI
• Integration API: can use both CSV/CORE and Relational/CORE transformations
• CORA tag: “Variable”
82
Compute Estimates
and Sampling Errors
Calibrate
Survey Data
ES
TIM
AT
IONCompute Estimates
and Sampling Errors
Calibrate
Survey Data
ES
TIM
AT
ION
Eurostat
Estimates and Errors Service
• Goal: use the calibrated weights to compute the estimates the survey has to provide (typically for different subpopulations of interest) along with the corresponding confidence intervals
• IT tool: Istat ReGenesees system
• Integration API: can use both CSV/CORE and Relational/CORE transformations
• CORA tag: “Statistic”
83
Compute Estimates
and Sampling Errors
Calibrate
Survey Data
ES
TIM
AT
IONCompute Estimates
and Sampling Errors
Calibrate
Survey Data
ES
TIM
AT
ION
Eurostat
Store Estimates Subprocess
• Goal: persistently store the
previously computed survey
estimates in a relational DB
• e.g. in order to subsequently
feed a data warehouse for
online publication
• IT tool: a set of SQL statements
• Integration API: Relational/CORE
transformation again
• CORA tag: “Statistics”84
Store Estimates
and Sampling Errors
Store Estimates
and Sampling Errors
Eurostat
Convert to SDMX Service
• Goal: retrieve the aggregated data
from the relational DB and directly
convert them in SDMX XML format
• e.g. to later send them to
Eurostat
• IT tool: ???
• Integration API: must support
SDMX/CORE transformations
• CORA tag: “Statistics”
85
Convert to
SDMX
STOP
Convert to
SDMX
STOP
Eurostat
Scenario Open Issues
• Besides I/O data, CORE must be able to handle “service
behaviour parameters”. How?
• e.g. to analyze a complex survey, ReGenesees needs a
lot of sampling design metadata, namely information
about strata, stages, clusters identifiers, sampling
weights, calibration models, and so on
• Enabling the CORE environment to support interactive
services execution is still a challanging problem
• we plan to exploit MAUSS-R and/or ReGenesees to test
the technical feasibility of any forthcoming solution
• How to implement a SDMX/CORE converter?
86
Eurostat
Demo Scenario
• Involves 3 typical processing steps performed by NSIs for sample surveys:
• Sample Allocation
• Sample Selection
• Estimation
• It has been used as empirical test-bed during the whole implementation cycle of the CORE environment
87
Eurostat
Rationale for the Scenario
• Minimality: very easy workflow (no conditionals,
nor cycles), can be run without a Workflow
Engine
• Appropriateness: addresses heterogeneity issues
• heterogeneity is precisely what CORE must be ableto get rid of
88
Eurostat
Spreading Heterogeneity over the
Scenario
• The Scenario incorporates both:
• Data Heterogeneity: Via data exchanged by CORE services belonging to the scenario process
• Technological Heterogeneity: Via IT tools implementing scenario services
A batch job based on a SAS script
Two full-fledged R-based systems
89
Eurostat
The Scenario at a glance
90
START
MAUSS-R
ALLOCATION
SAS SCRIPT
SELECTION
STOP
ReGeneseesSystem
ESTIMATION
Eurostat
Sample Allocation Service
• Overall Goal: determine the
minimum number of units to be
sampled inside each stratum,
when lower bounds are imposed
on the expected level of precision
of the estimates the survey has to
deliver
• IT tool: Istat MAUSS-R system
• implemented in R and Java
• CORA tag: “Statistics”
91
START
MAUSS-R
ALLOCATION
Eurostat
Sample Selection Service
• Goal: draw a stratified random
sample of units from the
sampling frame, according to the
previously computed optimal
allocation
• IT tool: a simple SAS script to
be executed in batch mode
• CORA tag: “Population”
92
SAS SCRIPT
SELECTION
Eurostat
Estimates and Errors Service
• Goal: compute the
estimates the survey has
to provide (typically for
different subpopulations of
interest) along with the
corresponding confidence
intervals
• IT tool: Istat ReGenesees
System
• R-based
• CORA tag: “Statistics”93
STOP
ReGeneseesSystem
ESTIMATION
Eurostat
CORE Follow up
Eurostat
CORE in Istat
• CORE is an Action of the Istat strategic plan Stat2015
• Period 2013-2015
• Objective: Usage of CORE platform in production scenarios ofIstat
• Plan for 2013:
• Implementation of engineering activities
• Usage of CORE to support sharing of generalized software functionalities– currently studying how to
• Usage of CORE in dissemination flow of the corporate architecture in conjunction with an ETL tool (Kettle) – currentlystudying how to
Eurostat
Development of CORE Services for ESS: Issues
• CORE is strictly related to the “Shared Services” technical cross-cutting issue of the ESS VIP (Vision Infrastructure Project) Programme
• Period 2013-2018
• Role: Supporting standardisation of the communication
protocol among standard statistical services
Eurostat
Issue 1: Relationship between CORE and SOA
• Hints for answering issue 1:
• CORE adopts a SOA design approach
• CORE services can be deployed as Web Services
• CORE do “imply”/”include” SOA technologies
• SOA technologies does not “imply”/”include” CORE
Eurostat
Issue 2: Relationship between CORE and GSIM
• Hints for answering issue 2:
• CORE did not have the purpose of defining yet another information model
• CORE takes into account the need for an information model
• Introduced only for demonstration purposes
• Hence from a design perspective CORE is open to adopt a full-fledged information model like GSIM
• CORE Model slot/CORE Domain Descriptor slot
Eurostat
Issue 3: Relationship between CORE and DDI/SDMX
• Hints for answering issue 3:
• DDI/SDMX provides “logical” information models
• GSIM serves a documentation purpose
• DDI/SDMX serve (mainly) a representation purpose
• CORE could be integrated with DDI/SDMX by:
• Mapping rectangular datasets representation of CORE data to such models
• Mapping in principle feasible as CORE model “less expressive”
Eurostat
Issue 4: CORE Deployment Issues in the ESS –SOA supporting platform
• Hints for answering issue 4:
• Need for designing a CORE deployment for the ESS
• Service repositories
• Data exchanges
• Security issues
• Performance issues
• ...