GQR Model to Support Requirements Elicitation for Content Rich
Systems
Leah Goldin
Afeka Tel-Aviv Academic College of Engineering, Tel Aviv, Israel
Keywords: Requirements Elicitation, Goal-Oriented Analysis, GQR Model, Content Rich Systems, GQM (Goal-
Question-Metric), Biomedical, Requirements Management, CMMI.
Abstract: Requirements elicitation for content rich systems is a huge challenge. Even using known techniques, does
not avoid diving into content details and get lost in hyperspace. We propose the GQR (Goal-Question-
Result) model to support the Requirements Elicitation process in elevating the elicitation discussions from
specific data elements to contextual structures of goal-question-result related content requirements, while
scoping the discussion to specific stakeholders. This paper characterizes the GQR model, shows its
advantages relative to the previous methods and illustrate its application by means of two case studies, one
biomedical and another related to CMMI requirements processes.
1 INTRODUCTION
The purpose of requirements elicitation is initial
extraction of the requirements. What methods are
best used for discovering and gathering
requirements, and how can we encourage customers
to better express their needs, are still a great
challenge to both Requirements Engineering (RE)
practitioners and researchers (Christel and Kang,
1992).
Requirements elicitation for content rich systems
is a further challenge. Even using known techniques,
does not avoid diving into content details and get
lost in hyperspace. While stakeholders
identification (Robertson and Robertson, 1999) is
nowadays practical and achievable, when inquiring
the requirements stakeholders to state their need and
requirements for developing a content rich system, it
is often impossible for them to envision their
requirements for the new system.
We propose the GQR (Goal-Question-Result)
model to support the higher demands of rich content
systems’ Requirements Elicitation process. The
latter deals with contextual structures of goal-
question-result related content requirements, while
scoping the discussion to specific stakeholders. This
paper characterizes the GQR model through its core
concepts, and illustrates its application by means of
two case studies, one biomedical and another
referring to CMMI requirements processes (CMMI,
2005).
1.1 Large Scale Information Systems
Requirements
Large scale Information Systems entail loads of data
at different levels of details and abstraction.
Sometimes the content is generated via different
interests not always thinking about who will use it
eventually. Thus requirements elicitation for such
content rich system is a significant challenge.
1.2 Requirements Elicitation
The work on Issues in Requirements Elicitation
(Neetu and Pillai, 2013) and (Christel and Kang,
1992) reported by the Software Engineering Institute
(SEI), surveys the problems identified in
implementing requirements elicitation processes,
and suggest a requirements elicitation framework to
cope with these inherent problems. Elicitation
problems are classified to classes of scope,
understanding and volatility. Problems of scope arise
from ill-defined boundary of the system along with
unnecessary incorporation of design information into
requirements. Problems of scope result from lack of:
1. Understanding the Organization in which the
system under development will be placed, i.e.,
46
Goldin, L..
GQR Model to Support Requirements Elicitation for Content Rich Systems.
In Proceedings of the 6th International Workshop on Software Knowledge (SKY 2015), pages 46-52
ISBN: 978-989-758-162-5
Copyright
c
2015 by SCITEPRESS Science and Technology Publications, Lda. All rights reserved
submitters of input to the target system and users
of the target’s system output, and
2. Understanding the System’s Mission within the
organization, i.e., ways in which the target
system will adapt/change the organization’s
means of doing business.
1.3 Goal-Oriented Requirements
Methods
Goal Oriented analysis methods like KAOS, Tropos,
i*, GBRAM (Bertrand et al., 1998), (Christel and
Kang, 1992), (Anton, 1996), (Lapouchnian, 2005)
and (Kavakli and Loucopoulos, 2003), include
concepts like: actions; entities; agents; goals and
constraints. These methods are formal and require
from the analyst high abstraction skills at different
levels of formal modeling. The current goal oriented
analysis method expect from the requirement
engineer to be creative and actually invent concepts
that are not mentioned in the request for proposal
(RFP) or other customers request for product
(Zdravkovic et al., 2013).
1.4 Related Work
Current requirements elicitation methods in
information systems (Neetu and Pillai, 2013) and
(Christel and Kang, 1992) include:
interviews as basic activity for discussing
requirements with customers,
using forms and questionnaires,
analyzing requirements via Business Process
Modeling (BPM), Data Flow Diagram
(DFD), and Entity Relation Diagrams (ERD)
(Biedermann and Grierson, 1995) and (Chen,
1966) etc.
1.5 Paper Organization
The remaining of the paper is organized as follows.
In section 2 we characterize the new GQR model. In
section 3 we give the biomedical case study as an
illustration of the application of the GQR model. In
section 4 we provide the CMMI requirements’
process areas case study as another illustration of the
GQR model. In section 5 we evaluate the GQR
model with respect to Requirements Elicitation. The
paper is concluded with a Discussion in section 6.
2 THE GQR MODEL FOR
REQUIREMENTS
ELICITATION
The Goal-Question-Result (GQR) was inspired and
based upon the Goal Oriented requirements
elicitation and Goal-Question-Metric (GQM)
methods (Solingen and Berghout, 1999). The
contextual structures of goal-question-result sets the
scene for the requirements elicitation process with
rational and operational context related to the
expected content requirements, while scoping the
discussion to specific stakeholders.
2.1 GQR Model
We have defined a high level model, shown in
Figure 1, enabling simple but effective structuring of
content investigations in terms of three primary
concepts Goals, Questions and Results (GQR).
The model is grounded by goal oriented
requirements engineering principles (Dardenne et
al., 1993) and is inspired by the Goal-Question-
Metric (GQM) method (Solingen and Berghout,
1999). The traditional GQM method used in
software measurements enables a planned collection
of data along with a systematic approach of
analyzing the metrics in order to get an effective
managerial feedback.
The Goal Question Result (GQR) method
rationale is to:
1. define your research goal,
2. state the research questions that are asked in
order to check if the goal is met, and
3. identify the Results that will be used to answer
these questions.
Goal Question Result
Investigation Data Set
Service
Question
Relationship
Entails Answered
+ Resource
+ Resource
Figure 1: Core concepts in the GQR method:
Investigation represent an elicitation inquiry that conveys
Goals, a Goal entails Questions that are answered by
Results. Results resource may be a data set or a service
that convey the content requirements.
GQR Model to Support Requirements Elicitation for Content Rich Systems
47
A Goal represents the investigation’s objective.
Goals can be more or less specific like “the role of
diet in cancer” or “investigate whether a disease
responds to a drug”. A goal entails one or more
questions that must be answered to achieve its
fulfilment. Questions are answered by way of data
sets or services (which in turn may consume data
sets) building up the actual Results that the analyst
was looking for. The goals, questions and results are
extracted from the customer request descriptions,
and are structured via GQR. This GQR model helps
scoping the content from which the requirements
will be further elicited consistently via every GQR
relation to Data-Set or Service of the content rich
system.
Due to its simplicity (natural/cognitive
presentation), people without a software modelling
skills can easily connect to the model and act upon
it. The GQR concepts appear in the customer
requests or user cases, as oppose to KAOS or i* that
require the invention of abstract concepts that are
not described in customer requests.
2.2 Potential Stakeholders
The requirements stakeholders are the ones that have
interest in the system, and can gain or lose
something as a result of this project. This interest
includes: functionality, revenue, status, compliance
with rules, etc. (Robertson and Robertson, 1999).
The Questions in the GQR model are related to
specific stakeholders which envision their
operational usage of the system to be developed.
Thus GQR is based on stakeholders identification,
i.e., Researcher, Data Manager, Biotechnician for
the PRM case study1 in Section 3, or the
organization roles like Product Manager, System
Engineer, Project Manager, Tester for the RMR case
study 2 in Section 4.
2.3 Existing Resources
Once the results are defined in the GQR model, they
are related to the resources of existing data from
which the content is retrieved. Existing data must
include documentation that stakeholders are using,
knowledge repositories or services.
3 CASE STUDY 1: CANCER
RESEARCH PLATFORM
REFERENCE MODEL
The NCRI Informatics Initiative (NCRI, 2015) has
set the goal to increase the impact of UK cancer
research and improve prevention and treatment of
cancer by effective use of informatics to manage and
exploit the diverse types of information currently
generated via an integrative platform (Begent et al.,
2005). The main aim is to enable the creation of an
open community where the different informatics
tools and resources available in the UK and
worldwide can interoperate with one another as a
whole.
Data sets have been generated by different
research groups around the world working across the
cancer research spectrum, that is, from basic to
clinical cancer research. Many of these data sets
have evolved separately and so present an
incoherent, fragmented landscape.
As an initial step in the platform development,
the author participated in a project focusing on the
requirements analysis and modeling of the Platform
Reference Model (PRM) (Finkelstein et al., 2006).
The analysis has been driven by a set of use cases
acquired by interviewing practitioners working in
the field. The main goals of the analysis have been
to understand how the various initiatives operating
in the cancer research field would effectively
cooperate with one another, what the relative roles
are, how they are actually used by practitioners. This
required a higher level perspective in defining the
use cases which are closer to user stories as defined
in the Agile development (Cohn, 2004) than to
standard use cases as described in (Cockburn, 2001).
3.1 The PRM Stakeholders
The PRM stakeholders identified by the NCRI Unit
are people involved directly or indirectly in the
research itself, i.e., scientific and clinical
researchers, clinicians and patients. Scientific
researcher include: Biologists, Chemists, Physicists,
Statisticians Bioinformatics experts, and Computer
Scientists, using the Platform to support their
experiments or studies. Clinical Researchers include:
Radiologists, Pathologists, Oncologists, using the
PRM to support their clinical trials.
3.2 The PRM Resources
The context where the NCRI platform will operate is
made up of a multitude of projects, resources and
initiatives that aim to support cancer research in
different ways. The field of cancer research is highly
dynamic reflecting the emergence of new
technologies, developing infrastructure and scientific
discovery.
SKY 2015 - 6th International Workshop on Software Knowledge
48
The systems that interface with the PRM can be
other systems such as informatics repositories. The
biomedical Terminologies and Ontologies include
all the standard vocabularies needed to access the
various informatics repositories, i.e., NCI (NCI,
2015) Thesaurus. Biomedical Informatics Resources
include the existing informatics systems that contain
raw data from different research areas, i.e., EBI
databases such as, ArrayExpress (EBI, 2015) for
micro-array data. Biomedical Publications include
approved and validated research results published in
medical journals, i.e., PubMed website (NCBI,
2015), PLOS (the Public Library of Science) (PLOS,
2015), PharmaKGB (an integrated resource about
how variation in human genes leads to variation in
our response to drugs) (PharmaKGB, 2015) etc.
3.3 The GQR Model for the PRM
The ever-increasing amounts of cancer research data
are collected and recorded in non-standardized ways
and are not in a suitable form for sharing, re-use and
integration. Thus, opportunities to gain new
knowledge are lost, results are not translated for
clinical use and experiments are repeated wastefully.
Planning cancer research via the GQR method
enables a planned collection of bioinformatics data
along with a systematic approach of analyzing the
results answers to the research questions, in order to
get an effective research result (wrt research goal).
The GQR analysis of the Genetic Variation in
Response to chemotherapy” case study in figure 2
includes the identification of research goal and
questions, along with the required Results mapped to
the existing Bioinformatics repositories.
G1
Q1.4
Q1.3
Q1.2
Q1.1
Investigate tumor genetic
variation response to
chemotherapy
Identify
specimens
Design
microarray
experiment
Compare clusters
to metabolic
pathways
Identify common
genetics
variations
R1 R5
R4
Report on genes
of interest based
on...
R3
conventional
clustering
methodologies
R2
Report on
specimens...
Figure 2: GQR analysis of the PRM. For the research
Goal of investigating the genetic response to
chemotherapy, Question Q1.1 rose by the Pathologist
regarding specimens’ identification while Question Q1.2
rose by the Radiologist regarding microarray experiments
(data and protocol). Each Question relays to a special
repository of relevant content Results.
This case study analysis obtained 1 research
goal, 4 research questions and 5 Results as described
in Figure 2:
G1 {Q1.1, Q1.2, Q1.3, Q1.4}
Q1 {R1, R2} | Q2 {R3} | Q3 {R3, R4} | Q4 {R5}
As part of the GQR analysis of the “Genetic
Variation in Response to chemotherapy” case study,
we have accompanied each dataset or Result
required to answer a research questions with
reference to existing bioinformatics repositories. For
example, European Bioinformatics Institute (EBI)
/Arrayexpress (EBI, 2015) required for microarray
analysis of R3, see table 1.
Table 1: GQR Reference to Bioinformatics Repositories.
4 CASE STUDY 2:
REQUIREMENTS
MANAGEMENT REPOSITORY
As part of the CMMI (CMMI, 2015) initiative, more
and more organizations decide to manage their
requirements via a requirements management (RM)
tool, thus establishing an RM Repository (RMR).
Most of the RM tools are based on Databases and
provide features of traceability required by the
CMMI, and it is a major technology transfer to
implement such a tool.
In order to benefit from the RMR, the RM
process should be defined and tailored accordingly
into the RM tool. An organization that wishes to use
an RMR needs to change its culture of work, and it
is not simple to elicit from people their RMR
requirements and needs for a new technology that
they have not experienced yet. To that end the
author has been using the GQR method in order to
elicit the RMR requirements and needs, while
focusing on project management goals that can be
answered by RMR reports.
4.1 The RMR Stakeholders
The RMR stakeholders are the usual project
Result
Data asset (data set / service)
Bioinformatics repositories
R3
Analyze [ and store] microarray data
using conventional clustering
methodologies
R3 Journals(JCO,Nature)
clustering tools
EBI/ArrayExpress
Pub-Med
GEO
caArray
R4
Report on genes of interest based on
expression in samples, and presence in
metabolic pathways of interest, which
are known to be chemotherapy targets
R4 REACTOME
KEGG
Journals
Pub-Med
GQR Model to Support Requirements Elicitation for Content Rich Systems
49
stakeholders, i.e., Project Manager, Product
Manager, System Engineer, Test Manager, Software
Engineer, etc. In this RMR case study, Pre-sales
Engineer, Proposal Manager, and Product Managers
played a major role in using the RMR for answering
RFPs (Request for Proposal).
4.2 The RMR Resources
The RMR resources are the usual project
documentation including: PRD (Product
Requirements Document) defining the product
features as from the R&D group to develop , System
and Subsystem Specifications (SSS), Software
Requirements Specifications (SRS) (DOD-Mil-std
498, 2000), Request for Proposal (RFP) in cases
that the customers define their needs specifically,
etc. Other project documentation items like Software
Test Plan (STP), User Manuals, Product Release
Notes, etc., can also be included in the RMR
depending on the project goal as will be described in
the following.
In this RMR case study, the project is based upon
requirements information found in written
documents such as product boilerplates, product
requirements definition (PRD) and product bulletins.
4.3 The GQR Model for the RMR
This case study presents the ``RFP traceability``
project in a large telecom company. The project goal
was to facilitate knowledge retrieval assisting in
RFP internal compliance and proposal reply, see
Figure 3. Internal compliance relates to the real
product knowledge needed for building the offering
by Pre-sales people to the customers.
Figure 3: GQR model of the RMR. For the Goal of
investigating RFP compliance, Question Q2.1 raised by
the Sales Engineer regards whether the product
requirements definition (PRD) complies with RFP, while
Question Q2.2 raised by the R&D VP refers to product
features availabity in existing product releases. Each
Question relates to a specifc product documentation of
relevant content Results.
The questions that are asked in an RFP
traceability project include:
Q2.1. Does the existing product comply with a
given RFP requirement?
Q2.2. Is a given RFP requirement available, and in
what release of product?
Q2.3. How to reply in the offering to a RFP
requirement? (What references are used for
that?)
This case study analysis resulted in 1 goal, 3
questions and 4 Results as described in Figure 3:
G1 {Q1, Q2, Q3 }
Q1 {R1, R2} | Q2 {R2, R3} | Q3 {R3, R4}
As part of the GQR analysis of the “RFP
traceability” case study in Figure 3, we added to
each Result required to answer a research question
the respective references to existing requirements
resources. For example, both RFP and Release notes
are required for R3, see table 2.
Table 2: GQR reference to requirements repositories.
5 EVALUATION OF THE GQR
MODEL AS SUPPORT TO RE
In the biomedical case study, the GQR investigation
model can be used as a mechanism for both
organizing and checking the biomedical informatics
needed to support a cancer research. The GQR
model is in the first place useful for designing a
well-defined research via goal/question modelling in
order to achieve effective research analysis of
outcomes. Once the research is managed via GQR, it
can be used as guidance for checking the required
bioinformatics resources. Due to the specialized
nature of the various cancer research sub-fields,
often only the experts interviewed for defining each
use case could provide us with the required
information for structuring the use cases and
identifying the content sources for each result.
In the CMMI requirements repository (RMR),
the GQR model encouraged the stakeholders to
express their ultimate questions that usually are
asked at most urgency and require lots of meetings
Result
Data asset (data set / service)
Requirements repositories
R2
Trace RFP requirements to product
existing features
R2 RFP
PRD
RFP2PRD
R3
Trace RFP requirements to actual
release notes
R3 RFP
Release notes
RFP2Release
SKY 2015 - 6th International Workshop on Software Knowledge
50
and discussions, and put a lot of pressure on people.
The GQR was found to be very useful in structuring
the content in the RMR, while specifying the
required content to fill in in order to provide the
required result.
6 DISCUSSION AND FUTURE
WORK
Content rich systems are difficult for requirements
elicitation, mainly because of the huge amounts of
content they process and the variety of potential
users that cannot envision their requirements from
the new system to be developed. The proposed GQR
(Goal-Question-Result) model directs and guides the
Requirements Elicitation process, in elevating the
elicitation discussions from specific data elements to
contextual structures of goal-question-result related
content requirements, while scoping the discussion
to specific stakeholders.
Problems of requirements scope result from lack
of understanding of the organization in which the
system under development will be placed. Especially
problematic in content rich systems is understanding
the users of the target’s system output, what output
is required for them, and how the target system will
change the organization’s means of doing business.
The basic structure of Goal-Question-Result acts
as a mean of defining the requirements scope, from
which the requirements will then be elicited. Goals
and questions are related to the requirements
stakeholders, thus encouraging them to simulate
their operational concept for the system under
development.
The results of the two case studies show that the
GQR model reveals most important content
requirements while helping stakeholders to articulate
their rationale via goals. This in turn is applied
iteratively between Goal-Question-Result rounds,
providing more and more contextual knowledge
about the system.
Future work will focus on traceability between
stakeholders and resources, while integrating
between data, stakeholders, and presentation
required from resources.
ACKNOWLEDGEMENTS
The author is grateful to Iaakov Exman for a critical
reading of early versions of the paper.
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