Artur Caetano, José Borbinha, José Tribolet, An Application of Role Modelling to the Decomposition of Business Processes

1. An Application of Role Modelling
to the Decomposition of Business Processes
Artur Caetano, José Borbinha, José Tribolet
Dep. of Computer Science and Engineering, IST, Technical University of Lisbon
&
Information Systems Group, INESC-ID Lisbon
artur.caetano@ist.utl.pt
CONFENIS 2012. September 2012, Ghent, Belgium.

2. Summary
Research questions
– How to decompose a business process according to
specific criteria?
– How to identify the atomic activities of a business
process (the activities that cannot be further
decomposed)?
Goals
– Create consistent views over the process model.
– Facilitate the identification of business services.
Approach
– Application of role modelling (separation of concerns)
– Method to decompose a process based on roles.

3. Agenda
1. Motivation.
2. Approach: role-based modelling.
3. Example of application.
artur.caetano@ist.utl.pt 3

4. Enterprise Architecture
 Enterprise architecture (EA) is a coherent whole
of principles, methods and models used to
analyse, design and realise the infrastructure,
processes and support systems of an
organization.
 EA artefacts cross-cut heterogeneous domains
such as strategy, people, processes, services,
information, IS, IT.
 Multiple views are required to address the
concerns of all stakeholders (cf. ISO 42010,
ArchiMate, TOGAF).

5. Enterprise Architecture
2-5 yrs
Strategic Indicators, External Products & Services,
Strategy
Contracts, Rules, Regulations, …
< 6 mo
Business Processes, Information Entities, Actors,
Business
Organizational Units, Operational Indicators, …
3-6 yrs
IS Infrastructure Software, Services, Components, Packages, …
6-10 yrs
Processing, Storage and Communication nodes
IT Infrastructure
and artefacts, …
artur.caetano@ist.utl.pt 5

6. Business Process Modelling
 Business processes describe how a set of
structured activities produce an output.
 Processes can be modelled using different
modelling languages and paradigms.
– Most focus on the specification of the workflow of a
process (transformational paradigm).
 BPMLs are often method-independent:
– do not provide the means to assess the qualities of
a model;
– do not prescribe process design principles.

7. Process Decomposition
A1
A1.1 A1.2 A1.3
...
A1.1.1 A1.1.2 A1.1.N
The specification of an atomic activity is always
context-dependent.
artur.caetano@ist.utl.pt 7

8. Process Decomposition
artur.caetano@ist.utl.pt 8

9. Process Decomposition
 Lack of criteria to determine when and how to decompose
an activity.
 Lack of criteria to determine whether an activity is atomic.
 Views over the same business process may be inconsistent.
Business Process
A1 A2 B1 B2 B3
A1.1 A1.2 A1.3 A2.1 A2.2  B1.1 B12 B2.1 B2.2 B3.1 B3.2
?
A1.2.1 A1.2.2
View #1 View #2

10. Agenda
1. Motivation.
2. Approach: role-based modelling.
3. Example of application.
artur.caetano@ist.utl.pt 10

11. Separation of Concerns
Separation of concerns, which, even if not
perfectly possible, is yet the only available
technique for effective ordering of one's
thoughts, that I know of. This is what I mean
by “focussing one's attention upon some
aspect”: it does not mean ignoring the
other aspects, it is just doing justice to the
fact that from this aspect's point of view, the
other is irrelevant.
Edsger Dijkstra, “On the role of scientific thought”, 1982.

12. Separation of Concerns
 SoC is an abstraction technique.
 Its main goal is to isolate the different concerns
(aspects) of a system in a given context.
 Isolated concerns are easier to analyse and
understand.
 SoC approach:
1. Identify the concerns (i.e. build a concern ontology).
2. Analyse the separated concerns.
3. Weave the concerns back together.

13. Role Modelling as SoC
 Entities (natural types) specify the structure (active and
passive) of a system.
 Role types describe the behaviour of each entity.
 Entities play roles in a specific collaboration context.
 An activity is a role-based collaboration between entities.
Credit
Person Book Bookstore
Card
Payment
Buyer Item Seller
Buy Item

14. Role Types and Natural Types
 Role type (e.g. Buyer, Seller)
– Founded: existence depends on other concepts
– Not rigid: looses identity outside context
 Natural type (e.g. Person, Book)
– Not founded: independent existence
– Rigid: universal (upper-domain) identity
N. Guarino. “Concepts, attributes and their relations”. Data & Knowledge Engineering (8), 249-261, 1992.

15. Agenda
1. Motivation.
2. Approach: role-based modelling.
3. Example of application.
artur.caetano@ist.utl.pt 16

16. Conference Organization
«Organizing a conference involves managing
paper submissions. Authors submit papers to
the conference. The papers are then reviewed
by at least two reviewers who produce a written
review. The reviewers cannot be the authors of
the paper»

17. Conference Organization
«Organizing a conference involves managing
paper submissions. Authors submit papers to
the conference. The papers are then reviewed
by at least two reviewers who produce a written
review. The reviewers cannot be the authors of
the paper»
 Concerns (role type ontology)
– Actor role (who)  Author, Reviewer
– Resource role (what)  Paper, Review

18. Conference Organization
«Organizing a conference involves managing paper
submissions. Authors submit papers to the
conference. The papers are then reviewed by at
least two reviewers who produce a written review.
The reviewers cannot be the authors of the paper»
Manage
Paper
resource: actor: 2..* resource:
Review Reviewer Paper
actor:
Author
artur.caetano@ist.utl.pt 19

19. Conference Organization
 View #1 “Who is doing what?”
 View #2 “What resources are being used?”
artur.caetano@ist.utl.pt 20

20. Example
Role-based Decomposition
Manage
Paper
resource: actor: 2..* resource:
Review Reviewer Paper
actor:
Author
Manage
Paper
A1 A2
resource: actor: resource: actor: resource:
Review Reviewer Paper Author Paper
Decomposition based on the “actor” role type.

21. Example
Role-based Decomposition
Manage
Paper
resource: actor: 2..* resource:
Review Reviewer Paper
actor:
Author
Manage
Paper
A3 A4
resource: actor: actor: resource:
Review Reviewer Reviewer Paper
actor: actor:
Author Author
Decomposition based on the “resource” role type.
artur.caetano@ist.utl.pt 22

22. Role-based Decomposition
 An activity is defined a collaboration between
entities playing roles.
 The decomposition method recursively separates
an activity into sub-activities while it contains
overlapping role types.
 An activity is considered atomic if it has no
overlapping role types (i.e. cannot be further
decomposed).
artur.caetano@ist.utl.pt 23

23. Example
Role Type Ontology
 A role type ontology specifies the role types (i.e. concerns)
applicable to a given domain.
 Upper-level ontologies specify domain-independent
concerns, such as:
– Actor – who
– Resources – what
– Locations – where
– Goals – why
– Events – when
 Domain-specific ontologies specify concerns applicable to a
given context. These can be refined from the upper-level
ontology.

24. Role Type Ontology
artur.caetano@ist.utl.pt 25

25. Summary
 The proposed method decomposes a business process based
on a role type ontology that specifies the concerns of the
stakeholders.
– Enables creating views over a process that focus on
specific concern.
– Enables identifying the atomic activities of a process
based on a set of concerns (role types).
– Facilitates the identification of business services (and thus
business - IS mapping).
 This abstraction technique reduces the problem of process
decomposition to the problem of identifying a suitable role
type ontology.

26. An Application of Role Modelling
to the Decomposition of Business Processes
Artur Caetano, José Borbinha, José Tribolet
Dep. of Computer Science and Engineering, IST, Technical University of Lisbon
&
Information Systems Group, INESC-ID Lisbon
artur.caetano@ist.utl.pt
CONFENIS 2012. September 2012, Ghent, Belgium.