ontology creation and management for requirements quality

Ontology creation and management within RQA

www.reusecompany.com

Ontology creation and management

2 September 20, 2011 (C) The Reuse COMPANY – http://www.reusecompany.com

Contents

Brief Introduction to RQA

Ontologies in System Engineering

The PDCA cycle and its application to Ontologies

Ontology Creation

Ontology Mantainment



What is the Requirements Quality Analyzer - RQA

The Requirements Quality Analyzer is a software tool that aids quality

assessment and improvement within requirements oriented systems and software projects.

RQA allows to define, measure, improve and manage the quality of requirements

specifications in systems and software projects.

The assessment is modeled by evaluating metrics.



RQA’s main business core

Metrics

Defining, measuring and managing metrics that affect Requirements represented in

Natural Language Text.



Metric´s need of knowledge about the domain of application

The more semantics we want to put in a metric, the more dependence on the

knowledge about the domain of application. In general, this rule is applied to

whatever System Development and Management process.

0% 25% 50% 75% 100%

Siz

e

Co

up

lin

g

Req

uir

em

en

ts

Read

ab

ilit

y

Tra

ce b

etw

een

Mo

du

les

Do

main

Term

s

Do

main

Verb

s

inco

nsi

sten

t

un

its ….. …..

Knowledge is packaged within a knowledge structure (from glossaries to ontologies)

The selection of the structure to use depends on the interest of the organization to

«understand and get use of» the possibilities each of them offers




In built Ontology in RQA.

0% 25% 50% 75% 100%

Siz

e

Co

up

lin

g

Req

uir

em

en

ts

Read

ab

ilit

y

Tra

ce b

etw

een

Mo

du

les

Do

main

Term

s

Do

main

Verb

s

inco

nsi

sten

t

un

its ….. …..

OUT OF THE BOX




In built Ontology in RQA.

0% 25% 50% 75% 100%

Siz

e

Co

up

lin

g

Req

uir

em

en

ts

Read

ab

ilit

y

Tra

ce b

etw

een

Mo

du

les

Do

main

Term

s

Do

main

Verb

s

inco

nsi

sten

t

un

its ….. …..

OUT OF THE BOX OPTIONAL



What is an ontology?

Ontology (from the Greek) is the philosophical study of the nature

of being, existence or reality as such, as well as the basic categories of

being and their relations.

Traditionally listed as a part of the major branch of philosophy known

as metaphysics, ontology deals with questions concerning

what entities exist or can be said to exist, and how such entities can be

grouped, related within a hierarchy, and subdivided according to similarities

and differences.

Parménides



Ontologies use within RQA

The Requirements Quality Analyzer is a tool that uses Natural Language

Processing (NLP) techniques to assess the quality of individual or sets of

requirements.

Storing conceptual information that makes it easier for a machine to

understand the real meaning of a requirement

Storing inference rules that allows the tool implement algorithms to emulate a

human reasoning

NL Reqs.

Reqs

Formal Representation

T1:

Semantic Knowledge

Harvesting

T2:

Information Retrieval and

Metrics calculation

Trace metrics

Coupling metrics

Inconsistent units

Other…



What is an ontology for TRC? Controlled vocabulary: valid terms, forbidden terms… Optionally can include a Glossary (description for every term)

Taxonomy: terms hierarchically organized

Thesaurus: hierarchies, associations, synonyms…

Light Ontology: syntactic and Semantic groupings for Terms and Actions (verbs). Domain terms and verbs

Ontology: inference rules for Identifying the semantics of the requirements



Controlled Vocabulary in RQA

Needed for assessing the quality of individual requirements using Text based

Metrics.

Using a glossary with different categories of terms, the ontology may store:

Business related Terms : those terms central to the business area the requirements are

related to

General Language Terms:

Invalid terms: those terms that could be banned out of a requirement such us

ambiguous terms,…

Engine

based

vehicles

Vehicules

Emissions

control

Pollution

emissions

Legislation

Environmen

tal impact

evaluation

Noise

and

vibratio

ns

Air

conditionin

g

Air flow

Conduct

Diesel

engines Gass Engines

Electric

Engines

Engines

Hibrid engines

Pressure

loss

Vehicle

structure

Doors

Door

structure

Window Security

Safety and

health

Hvac system



Controlled Vocabulary in RQA

UR044 : The Rad8 shall be able to identify hits at a minimum rate of 10 units per second

Rad8

shall

identify

hit

unit

minimum

second

…..

The

to

at



Taxonomies and Thesaurus in RQA

The Thesaurus stores relational information regarding the terms in the glossary.

Stakeholder

User

Administrator

Ordinary user

Customer

Administrator

Admin

Engine

based

vehicles

Vehicules

Emissions

control

Pollution

emissions

Legislation

Environmental

impact

evaluation

Noise and

vibrations

Air

conditioning

Air flow

Conduct

Diesel

engines

Gass Engines

Electric Engines

Engines

Hibrid engines

Pressure loss

Vehicle

structure

Door

structure

Window

Security

Safety and

health

Hvac system

Doors



Taxonomies and Thesaurus

UR044 : The Rad8 shall be able to identify hits at a minimum rate of 10 units per second

Rad8

identify

second

…..

Rad8 PTT Radar Sonar =

Distinguish =

UR03442 : The Radar shall be able to distinguish hits at a minimum rate of 10 elements per s

s =



Light Ontology: Semantics grouping

UR044 : The Radar shall be able to detect hits at a minimum rate of 10 units per second

Doppler radar

identify

Radar Sonar

Detect Recognize <DETECT>

Verb Semantic

<OBJECT DETECTION>

Term Semantic

UR563 : The Doppler Radar shall be able to Identify hits at a minimum rate of 10 units per

second

DOMAIN TERMS

Doppler radar Radar

DOMAIN VERBS

identify



Ontology: Inference rules

UR044 : The Radar shall be able to detect hits at a minimum rate of 10 units per second

Fulfills Detection Pattern 1

THE <OBJECT DETECTION> SHALL <DETECT> <ITEMS> AT

<MINIMUM> <RATE VALUE>

Detection Pattern 1

<<Detect>>

Radar Hits

<<Minimum

Value>>

10 units second



Inference Layer in RQA: Boilerplates

The inference rules layer of the Ontology allows us to identify and represent a

requirement into a graph (which is needed for the coupling functionality):

Boiler plates are used as patters

UR001: ….

UR023: The system shall send weekly notifications to the customers including our offers

URxxx: …

UR842: The application shall be able to notify periodically all of our offers to our clients

UR999: …

UR023

UR842

<<Notify>>

System Customer Offer



PDCA cycle applied to Ontology management

• How is the quality evolving?

• Do we need additional training?

• Are Global metrics working properly?

• Perform training

• Manage metrics

• Tune quality functions

• More communication

• Evolve the Ontology towards the planed complexity

• General training and communication

• Operate the tool

• Take actual measurements

• Take initial measurements

• Identify initial metrics and thresholds

• Define Quality Goals

• Define the metrics to reach with the Ontology and build it Plan Do

Check Act



Ontology PDCA: User’s Roles

Leads the domain Management process

Defines and controls the process

Solve conflicts

Evaluates PDCA for the Ontology

Improve project performances

Quality Cost Delays goals

Best practices fulfilling

Process improvement: training, support

Identify gaps: quality evolution vs teams

Improve work efficiency

Requirements Quality

Identify critical issues: bad formulations,

ambiguous terms inconsistencies

Process improvement: self training

RQA supports a multi-role ontology management within a software/systems intensive organization

Q

Domain

Manager

Domain

Experts

Domain

Architects



Ontology creation effort ROI

The ontology creation effort has a clear pay-off during time due to

maturation

The ontology change is relatively small for stable business companies

The Boilerplates modeling is done almost once for ever



A documents corpus is needed as input to the process

Manuals describing the domain

General purpose Glossaries (or specific ones if exist)

Existing Thesauri

Design documents (for design terms)

Ontologies through standard representations (OWL,…)

And , of course

Requirements (user, system, functional, …)

To identify terminology, relationships, boiler plates

Ontology creation in RQA: The process



Ontology creation in RQA : The process

Creating an ontology means several tasks:

The ontology may contain all the layers

Controlled Vocabulary

Taxonomies and Thesaurus

Light Ontology

Inference Rules: Boilerplates

An ontology usually fits a business domain: business dependent

The ontology is language dependent

The business domain evolves over time: PDCA cycle.



The activities to be carried out are:

Terms Identification

Terms Validation

Relationships Identification

Relationships Validation

Terms Semantics Identification

Verbs Semantic Identification

Terms and Verbs Semantics Validation

Boiler plates Identification and programming

Boiler plates presentation and acceptance

Definition of a a procedure to communicate new boiler plates

Ontology creation in RQA: The process



Ontology Evolution and Management in RQA V3

• How is the quality of the coupling results?

• Are we using new or different boilerplates?

• Are we getting in new domain areas?

• Work with the new discovered terms and verbs. Decide if they belong to the Domain, controlled vocabulary or are rubish.

• Find the correct place in the ontology for them and add Relationships

• Identify and program new boilerplates

• Operate the tool

• Calculate global metrics (index the requirements)

• Take actual measurements

• Identify the Domain areas to be modelled

• Identify the domain dynamics to be modelled

• Identify the Boilerplates that should be covered

Plan Do

Check Act

http://www.reusecompany.com

[email protected]

Margarita Salas, 16 2nd Floor

Innovation Center

LEGATEC Technology Park

28919 Leganés – Madrid

SPAIN – EU

Tel: (+34) 91 146 00 30

Fax: (+34) 91 680 98 26

mailto:[email protected]



ontology creation and management for requirements quality

Technology

reuse company

reuse company

requirements

pdca cycle

minimum rate

managementcontrolled

detect hits

software projects