The ‘discovery to delivery’ DLF reference model

UKOLN is supported by:

The ‘discovery to delivery’ DLF reference model

Andy Powell, UKOLN, University of Bath

[email protected]

JISC-CETIS Conference, Edinburgh, November 2005

www.bath.ac.uk

a centre of expertise in digital information management

www.ukoln.ac.uk

JISC-CETIS Conference, Nov 2005 2

Contents

• this talk summarises some draft work that has been done as part of the DLF Abstract Service Framework Working Group to develop a ‘reference model’ for the ‘discovery to delivery’ space– history – the IE– context - the DLF Abstract Service Framework

Working Group– terminology – the DLF model and ‘reference model’– the d2d reference model– issues


History - the JISC IE

• attempt to allow services offered within the JISC community to be joined together more seamlessly– JISC-funded, institutional, other

– allow users to ‘discover’, ‘access’ and ‘use’ resources – d2d

– not just library resources – wide range of heterogeneous resources

• a set of standards/interfaces• essentially ‘service oriented’

but work pre-dated thatuse of terminology


Context – the DLF

• Digital Library Federation – consortium of largely US research libraries but growing international membership – e.g. the British Library

• DLF Abstract Service Framework Working Group - applying a ‘service oriented’ approach to library services– see how library services fit into world populated by

Google, Amazon, eLearning systems, Grid services and eResearch, Web 2.0, etc.

– unbundle monolithic library systems into ‘service’ components


BIG DISCLAIMER

• everything I’m about to tell you may be wrong!• this presentation discusses work that is

currently in progress• the terminology may well change (in fact it is

already changing)• the use of the DLF model for things like d2d

may well change (in fact it is already changing)

• DLF keen to work with JISC on the eFramework to reach consensus


Terminology - the DLF model

Business requirement

Business process

Business function

Abstract service

Service binding

Deployed service

Business entity




Business process

Business function

Abstract service

Service binding

Deployed service

A business requirement is identifiable segmentof an organisation’s overall mission.

A business process is an identifiable portion of a business requirement. Business processes may be made up of business functions.




Business process

Business function

Abstract service

Service binding

Deployed service

Abstract services are discrete pieces of networked functionality (supporting a business process/function).

A service binding is an instantiation of an abstract service – a concrete data representation, API, Web service description, etc.




Business process

Business function

Abstract service

Service binding

Deployed service

A deployed service is a service binding available at a specific location on the network.

Business entity




Business process

Business function

Abstract service

Service binding

Deployed service

A business entity is something of interest – typically represented by metadata. The things that services are about.

Business entity


DLF reference model

• a DLF reference model is…• a document that describes all the

features of this model as used to meet a particular business requirement

• not clear how formalised this document can/should be?– human text vs.– UML (or some other modelling language)


Applying the DLF model…

• …to the discovery to delivery (d2d) ‘business requirement’ – the requirement for people to be able to discover

and access resources in the context of their learning and/or research activities

• in this case the requirement is met by allowing the end-user to undertake a number of ‘business functions’– enter, survey, discover, detail, request, deliver– each function is documented using UML use

cases


Enter

• entering the ‘system’• likely to have to be authenticated before

accessing resources– e.g. providing an Athens username

• may result in a personalised view of the landscape being presented

enter

authenticate buildLandscape

initiate

user provider


Survey/discover

• 'survey‘ is about identifying the collections that are of interest

• 'discover' drills down into each of the collections identified during the initial survey

• same ‘discovery’ strategies used in each

discoverinitiateuser provider

survey

useSavedRecord search

initiate

useSavedRecord search

browse alert initiate

assistQuery

assistQuery

browse alert initiate


Detail

• builds up knowledge about a particular resource– locations, formats, ratings and annotations,

terms and conditions, etc.

• find out enough to be able to request the resource

detail

locate getFormats

initiate

user providergetRatings getConditions


Request/deliver

• attempt to obtain resource– HTTP GET– inter-library loan– buying book from Amazon– etc.

• some level of authorisation may be required before delivery

request

deliver

authorise

initiate

initiate

initiateuser provider


Abstract services

• businessfunctionsandprocessessupportedby services

Enter Survey Discover Detail DeliverRequest

JISC IED2D

Authentic-ation

UserPreferences

ServiceRegistry

Search

Alert

Terminology

MetadataSchemaRegistry

Harvest

IdentifierResolver

Rating/Annotation

LinkServer

Terms andConditions

Authorisation

Authorisation

Authorisation

Terminology

Business Requirement

Business Process

Abstract Service


Abstract services

• each abstract service documented in terms of its behaviour, inputs, outputs and intelligence (the business entities it needs to know about)

• for example:

Search (Discover)Behavior: Accepts a structuredquery and issues a set of metadatarecords (a result set) in responseto the query.Intelligence: SchemaData in: Structured queryData out: Metadata record set

Link server (Detail)Behavior: Provides informationand/or links (i.e. URLs) associatedwith a resource based on ametadata record about thatresource.Intelligence:Data in: Metadata recordData out: Information and links


Service bindings

• each abstract service instantiated using one or more service bindings

• for example:

SearchZ39.50 (Bath Profile)SRW/SRUDC, IEEE LOMMETS, IMS-CP, MPEG-21 DIDL

Link serverOpenURL


Deployed services

• the set of service bindings deployed on the network

JISC-fundedcontent providers

institutionalcontent providers

externalcontent providers

brokers aggregators catalogues indexes

institutionalportals

subjectportals

learning managementsystems

media-specificportals

end-userdesktop/browser pr

esen

tatio

n

fusion

prov

isio

n

OpenURLlink servers

shared infrastructure

authentication/authorisation(Athens)

institutional profilingservices

terminology services

service registries

identifier services

metadata schema registries

© Andy Powell (UKOLN, University of Bath), 2005


Issues - workflow

• UML use-cases as presented here tend to imply a linear workflow– enter, survey, discovery, detail, request, delivery

• in practice, services likely to be joined together by end-users inarbitrary order asthey see fit

• not possible topre-determineworkflow usedin the wild?!

survey/discover

useRecorddetail

request

deliver

useResource


Issues – enter function

• ‘enter’ function OK if thinking about monolithic resource discovery application, e.g. a ‘portal’

• but doesn’t sit comfortably in scenario where end-user is joining services together to suit them

• authentication, authorisation, user-profiling likely to happen at multiple places in workflow– e.g. consider user moving from Google to

Connotea to OpenURL link server to library OPAC to A&I service to lngenta Journals …


Issues – survey vs. discover

• this work is draft and undergoing inactive change

• not clear that this is the right breakdown of ‘business functions’

• ‘survey’ vs. ‘discover’ distinction not clear – particularly since same strategies might be used to find ‘annotations’, ‘terms and conditions’, etc.


Issues – use of UML

• not building monolithic applications• rather, we are building loosely-coupled

services that will be joined together and choreographed by a variety of applications

• use of UML in this context is somewhat ‘unusual’

• might be better to use other approaches instead of/as well as UML– e.g. Mindmaps


Discussion…

Education

The ‘discovery to delivery’ DLF reference model