Policy modelling, derivation and Quality Assurance 29 October, PERICLES Workshop Belgian Institute for Space Aeronomy, Brussels

1. GRANT AGREEMENT: 601138 | SCHEME FP7 ICT 2011.4.3
Promoting and Enhancing Reuse of Information throughout the Content Lifecycle taking account of Evolving
Semantics [Digital Preservation]
Fabio Corubolo - University of Liverpool
29 October, PERICLES Workshop
Belgian Institute for Space Aeronomy, Brussels

2.  Motivation
 Overview
 Definitions (Policy, QA)
 Policy model
 Policy derivation
 QA of Policies
 Policies in the ecosystem model
 Examples

3.  Managing and enforcing policy (one of the project
objectives) in the overall infrastructure, is
qualified, time consuming work
 Good management requires Quality Assurance
 Change an obsolescence is constant
 Digital preservation approaches for ecosystem
management are useful NOW, and in the long term

4.  QA used to manage change by:
◦ validating the correct application of policies in the
ecosystem.
◦ detecting potential conflicts
◦ constraining the ecosystem evolution
 Policy derivation
◦ Adding dependencies to the ecosystem model by
mapping polices to policies and other ecosystem
entities
 High-level policies
 Intermediate-level policies
 Concrete implementations via processes and technical
services

5. Change and model
analysis
Registration /
Model update
Validation
Entity registry /
Model repository
Workflow engine
Components
Digital ecosystem
User interface
Model editor /
Change explorer
Preservation
process
User
input
Trigger
s
Entity,
dependencies,
metadata
Change actions
Process execution
Content
Compiled
workflow
Models and
policies
Workflow
and results
Validation
results
Model
views
Knowledge base
User
input
Uses
Uses
?

6.  Quality Assurance (QA): a program for the systematic
monitoring and evaluation of the various aspects of a project,
service, or facility to ensure that standards of quality are
being met (Webster)

7.  Used in very diverse meaning in English, and in IT.
◦ A policy is a plan that defines the desired state inside an
ecosystem. A policy describes the 'what' (guidelines) and not the
'how' (implementation). (Pericles)
◦ A policy is a statement of intent, and is implemented as a
procedure or protocol. (Wikipedia)
◦ A formal statement of direction or guidance as to how an
organization will carry out its mandate, functions or activities,
motivated by determined interests or programs (Interpares)
◦ … Many more specific uses: access control, security, load
balancing, configuration … policies
 Our definition:
“high and intermediate level natural language descriptions of
an institution’s aims/goals, with what constraints.”

8.  ID, Name
 Version
 Policy statement (formal or not formal)
 QA criteria (condition-action, rule, Unit
test or other formal definition)
 Purpose (reason of creating)
 Dependencies
 Classification
 Owner
 Responsible for the application
 Level on compliance (must, should, …)
…

9. How:
 Trace the highest level policies, through
intermediate levels, down to concrete
implementations such as rules (constraints) ,
procedures, WFs, services
Why:
 High level => abstraction from detail (principle)
=> less change in the long term
 Rationalise the ecosystem structure by showing
the dependencies between different level-policies,
procedures/services and other ecosystem entities
 Enable policy based methods for QA and validation

10. High level abstract policy
Independent from any
model structure
Level of
abstraction Policy entities
Intermediate level(s) policy
Other Ecosystem
entities
(At different level
of abstractions)
Connects to abstract level
entities
Link to concrete
implementation: workflow,
procedure, services
QA methods
High level intent
and constraints in
natural language
Detailed intent and
constraints in
natural language
- Unit tests
- Rule language
constraints (PAL,
SWRL)
- Validation queries to
ecosystem model
(SPARQL)
Services
DOs
Users
Processes,
rules, workflows
Infrastructure,
SW etc

11. DO
1
TS
1
DO
2
ON
1
TS
2
TS
3
TS
4
TS
5
Models: Process (BPMN) Dependency (LRM) Semantic dependency
depends on
depends on
depends on
semantically
depends on
semantically
depends on
process process
PO
1
PO
2
depends on
TS
6
TS
6
depends on depends on

12.  Top-down: Know what processes depend on a
specific policy, and be aware of consequences of
change
 Bottom-up: Know what policy is motivating or
depends a particular entity; so that any change
related to that entity could trigger policy re-
validation
 Notice when the practice starts to deviate from the
policies, that will help update the policies or
correct the practice depending on the case.

13.  Notice when practice starts to deviate from
policies
http://arstechnica.com/tech-policy/2015/08/cops-decide-to-collect-less-license-plate-data-after-80gb-
drive-got-full/

14. ● Unit tests on policy
● Rule/action language constraints (PAL, SWRL)
● Risk analysis on the ecosystem graph
● Validation queries to ecosystem model (SPARQL)
● Policy conflict detection and change management

15. Process
PolicyDigital
Object
Technical Service Community
User uses TS to get access to Processes and
Digital Objects
manage
executes
rulebase, constraints, validation
procedure, rulebase, constraints, validation
procedure, rulebase,
constraints, validation
rulebase,
constraints,

18.  Understand the risks and impact associated with a
change of policy.
 Be aware of changes (external and internal) that
may invalidate a policy implementation.
 Understand and control how the content of the
archive may evolve over time.
 When a standard checklist of policies needs to be
implemented to adhere to a standard, the policy
derivation and mapping will help prove the
correct implementation.

19.  It can tie in existing systems and methods
and does not mandate a specific model or
complete buy in
 Does not impose organisation structure; or
policy or process language, but can be
integrated in existing ones
 QA methods can be implemented as well in
any language or fashion

20.  To support QA of research outputs
 Automated validation of compliance with
policies and standards
◦ ease the pressure on scientists as far as policy
compliance is concerned
◦ Integrate preservation practices at the moment of
creation to support reuse; integrates in existing
infrastructure
◦ Helps to keep track of the decisions made when
implementing policies and their rationale