Date post: | 01-Jan-2016 |
Category: |
Documents |
Upload: | neal-chambers |
View: | 213 times |
Download: | 0 times |
1
Ontology-based Semantic Annotatoin of Process
Template for Reuse
Yun Lin, Darijus StrasunskasDepart. Of Computer and Information ScienceNorwegian Univ. Of Science and Technology
2
Agenda
Problem Statements Proposed Approach – Semantic Annotation
Ontological Basis and Meta-Model Mediator Semantic Annotation of Process Template
Applications Conclusions and Future Work
3
Problem Statement
A process template is abstracted from a process model instance for reuse purpose.
Reuse of process templates improves the quality of process modeling by reflecting previous knowledge and experience.
Process templates are stored in the distributed model repositories.
Storage and retrieval of process templates have to be considered.
4
Problem Statement
Reuse limitations of current model templates : Same process modeling language Same modeling tool Difficult to be queried beyond an enterprise Same terms are required when querying
(keyword-based query)
5
Problem Statement
The limitations are caused by semantic interoperability problems.
Semantic interoperability problems: Model level
Terms are used differently for the same concept in two models, e.g. ‘Client’ in model A and ‘Customer’ in model B; ‘purchase’ in model A and ‘buy’ in model B.
Conceptualization mismatches, e.g. ’City’ is a class in model A and it is a attribute of another class in model B; ’finish’ is an action in model A but it is a state in model B.
6
Problem Statement
Semantic interoperability problems: Meta model level
Same concept but different terms are used in different modeling languages, e.g. ‘agent’ (ActionWorkflow) ‘actor’ (Core Plan Representation)
Same terms but the concepts are not totally same, e.g. ’activity’ is the atomic concept in PSL (Process Specific Language), but it is not an atomic concept in WooRKS
7
Assumption: process models in a same domain have common concepts process modeling languages have sufficient similarities of
constructs
Common understanding(process ontology)
Model
Meta-model
Common understanding(domain ontology)
Model
Meta-model
8
Proposed Approach
A common semantic annotation structure for process templates.
Model profile annotation
Model content annotation
Meta-model annotation
Figure1. Three model annotation aspects
Model as a whole product
Model fragments
Modeling language
9
Proposed Approach
Model Profile Annotation The basic description information about a process
model template such as problem domain of the template, name of the template, author of the template, date of creation and etc.
Refer to the description structure of patterns
10
Proposed Approach
Model Content Annotation Contents of a process template: process and
doamin parts Process part: workflow description Domain part: object-relation model (class model, ER
model) Reference ontology
Process reference ontology, process patterns, thesaurus
Domain reference ontology, domain thesaurus
11
Proposed Approach
Model Content Annotation Assumption: all process templates can be
represented in XML/RDF. Markup annotation approach ’semAnn’:
12
Proposed Approach
Meta-model Annotation Mapping process modeling languages into a
semantics agreed process template modeling language.
Annotate schema (XML Schema or RDF Schema)
13
Ontological Basis
General Process Ontology (GPO) A set of concepts usually for describing semanitcs
of a process Based on BWW-ontology and refer to other
process ontologies and process modeling languages, such as TOVE, PIF-CORE, EEML, BPMN, BPML, PSL etc.
14
General process ontology (GPO)
Activity
Artifact
State
Transformation
participates_in
Exception
handled_by
raises
Condition
has
has
changes performed_by
ordering
resulted_from
Actor-role
interacts with
is_kind_of
partof
constrained_by
Set Attributelist Atom
{ }
+
RML graphical notations
Basic constructs:
Aggregation
Generalization (disjoint)
Generalization (overlapping)
Association
Classification
Hierarchical abstraction constructs:
Unspecified relation between A and B
Into function A B
Onto function A B
A relation, where each element of A canrelate to one element of B
A 1:1 partial correspondence between A and B
Functions (f: A B):
A B
A B
A B
A B
A B
15
Process Template Modeling Language (PTML)
Process templates are models and a neutral process modeling language provides a unified way to represent process templates.
Constructs of PTML try to cover most common and core constructs of various process modeling languages.
PTML is derived from GPO. PTML is defined in RDFS or OWL.
16
Process Template Modeling Language (PTML)
Flow Junctioncombine
Activity_element
Input
Output
Exception_element
has_condition
Artificate_element
has_artifact
combine
combine
State_property
Actor-role_element
has_actor-role
has_state
has_state
has_input
has_output
has_exception
from tohandled_by
Condition_element
17
Process Template Modeling Language (PTML)
Note: PTML is not intended to be created as a
completed executable process modeling language.
Impossible to make exact one-one construct mapping between PTML and a specific process modeling language.
A way of storing and representing the core model of process.
18
Semantic Annotation of Process Template Applications
Annotate process templates and store them in repositories
Retrieval desired process templates Reuse found process templates in new
projects
19
DataLocal
process template
Reference domain ontology, thesaurus
Process template
General Process Ontology (GPO)
Annotated process template
Profile annotation information
Local domain model
Meta model of a specific process
modeling language
Meta model of the Process Template
Modeling Language
(PTML)
link to link to
annotated_by(model content
annotation)
represented_by represented_by
store_in
annotated_by(model profile annotation)
annotated_by(model content annotation)
mapping
map
ping
derived_from
annotated_by(model content
annotation)
annotated_by(meta model annotation)
Domain part
Process part
Meta model part
21
A Simple Example
An EEML process model template includes: Task: purchase Personrole: client (defined in the local domain
model) The local process template is exported into a XML
file, and linked to the local domain model in which roles and resources are defined.
The EEML is defined in XMLS or DTD.
22
DataLocal
process template
Reference domain ontology, thesaurus
Process template
General Process Ontology (GPO)
Annotated process template
Profile annotation information
Local domain model
Meta model of a specific process
modeling language
Meta model of the Process Template
Modeling Language
(PTML)
link to link to
annotated_by(model content
annotation)
represented_by represented_by
store_in
annotated_by(model profile annotation)
annotated_by(model content annotation)
mapping
map
ping
derived_from
annotated_by(model content
annotation)
annotated_by(meta model annotation)
Domain part
Process part
Meta model part
24
DataLocal
process template
Reference domain ontology, thesaurus
Process template
General Process Ontology (GPO)
Annotated process template
Profile annotation information
Local domain model
Meta model of a specific process
modeling language
Meta model of the Process Template
Modeling Language
(PTML)
link to link to
annotated_by(model content
annotation)
represented_by represented_by
store_in
annotated_by(model profile annotation)
annotated_by(model content annotation)
mapping
map
ping
derived_from
annotated_by(model content
annotation)
annotated_by(meta model annotation)
Domain part
Process part
Meta model part
25
Meta-model Annotation
Meta model mapping EEML: task PMTL: activity element EEML: personrole PMTL: actor-role element
Mapping Reasoning with general process ontology SKOS(Simple Knowledge Organization Systems) Other mapping tools
26
Meta-model Annotation
SKOS is an RDF schema for representing thesauri and similar types of knowledge organization system (KOS).
Construct task in EEML is replaced by ‘Activity_element’ in PTML.
Process template is a RDF or OWL-based file.
27
Model Content Annotation – domain content annotation
Local domain model is a local domain ontology
Reference domain ontology or thesaurus is an agreed collection of concepts and their relations within a certain domain.
Local concepts are annotated by common understanding concepts.
Mapping of local doamin ontology and reference domain ontology
28
Model Content Annotation – domain content annotation
Person
Customer
client
Reference domain ontology, thesaurus
annotated_by(model content
annotation)
Domain model annotation
<skos:Concept rdf:about="uri://domainmodel#client"> <skos:preLabel>client</skos:preLabel> <skos:altLabel>customer</skos:altLabel> </skos:Concept>
Local domain model (ldm)
<rdfs:Class rdf:id=”client”/> …
29
Model Content Annotation – process content annotation
Annotate model fragments using GPO Apply the underlying relationship between GPO and PTML Annotate fragments with composed constructs (workflow
patterns)
Use ’semAnn’ annotation way
30
Annotatoin Result
The abstracted template is represented by the process model template language.
The IDs of model elements are reindexed. The semantics of the model elements are
also annotated by the general process ontology.
The terms can be replaced by synonym. The annotated domain model is linked to the
template.
31
Template Query Application
Query annotate
General process ontology
Annotated query
DataAnnotated
process model template
search
Reference domain ontology
Process model template result
32
Template Reuse Application
Three operations on a template Domain specialization Process Refinment Required process modeling language
transformation
33
Conclusions and Future Work Semantic interoperability issue of process models is vital in the following
scenario: Process models exchange Process models integration Process knowledge sharing
Process templates retrieval and reuse are applications normally used in above scenario.
Related work Services-oriented: Bernstein et al., ’Towards High-Precision Service Retrieval’;
Michael Kifer et al. ’A Logical Framework for Web Service Discovery’; Patil et al. ’METEOR-S Web Service Annotation Framework’ etc.
Process Ontology: MIT process handbook, OWL-S, PSL, Aitken and Curtis’s ’Design of a Process Ontology: Vocabulary, Semantics and Usage’, UEML
XML-based model exchange: XMI, Vanderhaeghen et al. ’XML-based Transformation of Business Process Models – Enabler for Collaboratiive Business Process Managemenrt’ and others
Contributions: Two-level semantic interoperability of process templates: meta-model level and model
level. Semantic annotation structure GPO and PTML
34
Conclusions and Future Work This is ongoing work. Some work is refined after this paper
GPO is refined (GPO and PTML are combined); Semantic Annotation Model (Semantic Web Services technology
is applied, such as OWL-S.) Goal-driven query
Future work Continue to enrich semantics covered by GPO (refer to some
process modeling languages comparison framework) Formulize semantics of GPO Refine semantic annotation model Semantic reasoning with annotation information (semantics
mapping, WordNet, Racer) Prototype of semantic annotation and semantic retrieval of
process templates