The document discusses the critical aspects of requirements engineering, highlighting its reliance on cognitive and social sciences for improving the process of eliciting and modeling requirements. It emphasizes the importance of communication, stakeholder agreement, and adaptation to evolving requirements, along with various elicitation and modeling techniques. Additionally, it outlines significant research topics, challenges, and recommendations for enhancing the practices and technologies in the field.

1. Requirements Engineering:
Research topics
CECS 542
Dr. Birgit Penzenstadler 1
Photo credit: Sam Hull, Unsplash

2. Hot research topics in RE
• Paper by Nuseibeh and Easterbrook, 2000
• Update paper by Cheng and Atlee in 2007
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3. Source
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4. CogniIve and social sciences as
foundaIon
• RE draws on the cogniIve and social sciences to provide
both theoreIcal grounding and pracIcal techniques for
eliciIng and modelling requirements:
• Cogni&ve psychology provides an understanding of the
difficulIes people may have in describing their needs [62]
• Anthropology provides a methodological approach to
observing human acIviIes that helps to develop a richer
understanding of how computer systems may help or
hinder those acIviIes [29].
• Sociology provides an understanding of the poliIcal and
cultural changes caused by computerisaIon.
• Linguis&cs is important because RE is largely about
communicaIon.
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5. Requirements to elicit
• Boundaries
• Stakeholders
• Goals
• User tasks / use cases
à All sounds familiar, right?
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6. ElicitaIon techniques
• TradiIonal techniques (surveys, interviews)
• Group elicitaIon techniques (workshops)
• Prototyping
• Model-driven techniques (e.g., KAOS)
• CogniIve techniques (card sorIng)
• Contextual techniques (ethnographics)
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7. Modeling and analyzing requirements
• Enterprise modeling
• Data modeling
• Behavior modeling
• Domain modeling
• Modeling NFRs
• Analyzing requirements models
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8. CommunicaIng requirements
• RE is not only a process of discovering and specifying requirements, it is also
a process of facilitaIng effecIve communicaIon of these requirements
among different stakeholders
à ensuring that they can be read, analysed, (re-)wriben, and validated.
• The focus of requirements documentaIon research is ocen on specificaIon
languages and notaIons, with a variety of formal, semi-formal and informal
languages suggested for this purpose, from logic to natural language
à different languages have been shown to have different expressive and
reasoning capabiliIes.
• What is increasingly recognised as crucial, however, is requirements
management – the ability, not only to write requirements but also to do so
in a form that is readable and traceable by many, in order to manage their
evoluIon over Ime.
• One abempt to achieve readability has been the development of a variety
of documentaIon standards that provide guidelines for structuring
requirements documents.
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9. Agreeing requirements
• As requirements are elicited and modelled, maintaining agreement with all
stakeholders can be a problem, especially where stakeholders have
divergent goals.
• Recall that valida&on is the process of establishing that the requirements
and models elicited provide an accurate account of stakeholder
requirements.
• Explicitly describing the requirements is a necessary precondiIon not only
for validaIng requirements, but also for resolving conflicts between
stakeholders.
• Techniques such as inspecIon and formal analysis tend to concentrate on
the coherence of the requirements descripIons: are they consistent, and
are they structurally complete?
• Requirements validaIon is difficult for two reasons:
– The first reason is philosophical in nature, and concerns the quesIon of truth
and what is knowable.
– The second reason is social, and concerns the difficulty of reaching agreement
among different stakeholders with conflicIng goals.
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10. Evolving requirements
• Successful socware systems always evolve as the
environment in which these systems operate changes and
stakeholder requirements change. Therefore managing
change is a fundamental acIvity in RE [9].
• Changes to requirements documentaIon need to be
managed. Minimally, this involves providing techniques and
tools for configuraIon management and version control
[22], and exploiIng traceability links to monitor and control
the impact of changes in different parts of the
documentaIon.
• Finally, the development of socware system product
families has become an increasingly important form of
development acIvity.
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11. Integrated requirements engineering
• RE is a mulI-disciplinary acIvity, deploying a variety of techniques and tools
at different stages of development and for different kinds of applicaIon
domains. Methods provide a systemaIc approach to combining different
techniques and notaIons, and method engineering [10] plays an important
role in designing the RE process to be deployed for a parIcular problem or
domain. Methods provide heurisIcs and guidelines for the requirements
engineer to deploy the appropriate notaIon or modelling technique at
different stages of the process.
• A variety of approaches have been suggested to manage and integrate
different RE acIviIes and products. Jackson, for example, uses problem
frames to structure different kinds of elementary and composite problems
[39]. His argument is that idenIfying well-understood problems offers the
possibility of selecIng corresponding, appropriate, well-understood,
soluIons.
• An alternaIve approach to organising, selecIng and tailoring mulIple
methods is through the use of mulIple perspecIves or views of
requirements [16; 26].
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12. Jackson’s problem frames
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13. Decade 1990-2000
(before publicaIon)
During 1990-2000, we can discern the emergence of three radical new ideas that
challenged and overturned the orthodox views of RE. These three ideas are closely
interconnected:
• The idea that modelling and analysis cannot be performed adequately in isolaIon
from the organisaIonal and social context in which any new system will have to
operate. This view emphasised the use of contextualised enquiry techniques,
including ethnomethodology and parIcipant observaIon [29; 63].
• The noIon that RE should not focus on specifying the funcIonality of a new
system, but instead should concentrate on modelling indicaIve and optaIve
properIes of the environment 2 [84] . Only by describing the environment, and
expressing what the new system must achieve in that environment, we can
capture the system’s purpose, and reason about whether a given design will meet
that purpose. This noIon has been accompanied by a shic in emphasis away from
modelling informaIon flow and system state, and towards modelling stakeholders’
goals [15] and scenarios that illustrate how goals are (or can be) achieved [51].
• The idea that the abempt to build consistent and complete requirements models
is fuIle, and that RE has to take seriously the need to analyse and resolve
conflicIng requirements, to support stakeholder negoIaIon, and to reason with
models that contain inconsistencies [28].
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14. N&E’s PredicIon for 2000-2010
• Development of new techniques for formally
modelling and analysing properIes of the environment
• Bridging the gap between requirements elicitaIon
approaches based on contextual enquiry and more
formal specificaIon and analysis techniques.
• Richer models for capturing and analysing non-
funcIonal requirements.
• Beber understanding of the impact of socware
architectural choices on the prioriIsaIon and
evoluIon of requirements.
• Reuse of requirements models.
• MulIdisciplinary training for requirements
pracIIoners.
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15. Source
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16. Source
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17. Source
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18. Hot topics
• Scale
• Security
• Tolerance
• Increased Reliance on Environment
• Self-Management
• GlobalizaIon
• Methodologies, paberns, and tools
• Requirements Reuse
• EffecIveness of RE technologies
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19. Scale
• Large scale and ultra-large
scale systems
à need to manage tens of
thousands of requirements
• Systems of systems
• Cyber-physical systems
• E.g. future intelligent transportaIon-management
systems, criIcal infrastructure protecIon systems
(e.g., systems managing power grids, bridges,
telecommunicaIon systems), integrated health-care
systems, and disaster-response systems
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20. Security
• IdenIfy and document potenIal security threats:
idenIfies assets, idenIfies vulnerabiliIes in the
context of potenIal threats, and specifies
countermeasures to protect against these threats
• E.g. in misuse cases and their miIgaIon
• An alternaIve approach would take a top- down
view of security requirements, and base
requirements on organizaIonal structures, such
as lines of authority, “separaIon of duIes,
delegaIon, roles, groups,” access policies, and so
on
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21. Tolerance
• Socware is increasingly used to automate criIcal applicaIons and
services, such as transportaIon vehicles and systems, financial
decisions and transacIons, medical care, military command and
control, and so on; in which security and assurance requirements
are paramount.
• However, given the complexity of such systems, with respect to
size, decentralized decision-making, and variability, the SE and RE
communiIes may need to socen their views and expectaIons for
security and correctness.
• Sufficient Correctness: The degree to which a system must be
dependable in order to serve the purpose its user intends, and to do
so well enough to sa&sfy the current needs and expecta&ons of
those users.
• à focus on requirements for acceptable behavior and on what it
means for a system to be “healthy”
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22. Increased reliance on
environment
• Cyber-physical systems (CPSs) are a new generaIon of engineered
systems in which compuIng and communicaIon are Ightly
coupled with the monitoring and control of enIIes in the physical
world
• Example cyber-physical systems include intelligent transportaIon
and vehicle systems; automated manufacturing; criIcal
infrastructure monitoring; disaster response; opImizaIon of
energy consumpIon; smart wearable apre for health care,
personal safety, and medical needs; and efficient agriculture
• To reason about an integrated system, it becomes necessary to
formalize the properIes of the environments with which the
socware will interoperate.
• à There need to be beber techniques for integraIng models of the
environment, interface devices, and socware components.
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23. Self management
• Growing interest in self-managing systems, in which the socware system
is aware of its context and is able to react and adapt to changes in either
its environment or its requirements – such as a mobile device, whose
available services vary with the user’s locaIon and with the local service
provider(s).
• Examples of such systems include self-healing systems that are able to
recover dynamically from system failure, faults, errors, or security
breaches; and self-op&mizing systems that are able to opImize their
performance dynamically with respect to changing operaIonal profiles.
• RE challenges:
– IdenIfying and specifying thresholds for when the sys- tem should adapt
– Specifying variable sets of requirements
– Matching requirements alternaIves to run-Ime needs
– IdenIfying correctness criteria for adapIve systems
– Verifying models of adapIve systems and their sets of possible behaviors
– Monitoring the system and environment, against the current requirements
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24. GlobalizaIon
• Global soEware development is an emerging paradigm shic
towards globally distributed development teams (exploit a
24- hour work day, capitalize on global resource pools, de-
crease costs, and be geographically closer to the end-
consumer).
• Downside: communicaIon gaps
• Challenges:
– 1. new or extended RE techniques are needed to support
outsourcing of downstream development tasks, such as design,
coding, and tesIng.
– 2. to enable effecIve distributed RE, i.e. manage distributed
requirements elicitaIon, distributed modeling, distributed
requirements negoIaIon, and the management of distributed
teams
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25. Methodologies, Paberns,
and Tools
• The transfer of RE technologies from research into pracIce would benefit
from beber advice on how to apply the technologies more systemaIcally.
• The goals of this type of engineering-style research are to improve the
producIvity of the requirements analyst and to improve the quality of the
resulIng requirements arIfacts.
• For example, just as pa3erns help to ease the creaIon of logic
expressions, research into idioms and paberns for other modeling
problems and notaIons would improve the produc6vity of modelers.
• Similarly, modeling conven6ons, methodologies, and strategies all help to
simplify RE techniques so that the techniques can be used successfully by
typical pracIIoners.
• Because paberns and strategies are, or suggest, parIal soluIons, they
help also to impose some level of uniformity and predictability in the
resulIng requirements descripIons.
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26. Methodologies, Paberns,
and Tools
• Despite the significant advances that have been made
in requirements modeling and notaIons, there has
been lible work on how to interconnect various types
of requirements models.
• Well-defined approaches to interrelaIng requirements
goals, scenarios, data, funcIons, state-based behavior,
and constraints are needed to address this
fundamental problem.
• Further research is needed on how to integrate RE
technologies, so that pracIIoners know how to apply
individual technologies effecIvely and synergisIcally.
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27. Requirements Reuse
• Another approach to making RE tasks more
prescripIve and systemaIc would be to facilitate the
reuse of exisIng requirements arIfacts. The most
strategic form of requirements reuse is product lining,
• A key RE challenge for product-line development
includes strategic and effecIve techniques for
analyzing domains; idenIfying opportuniIes for
product lining; and idenIfying the scope,
commonaliIes, and variabiliIes of a product line.
• A second challenge relates to how requirements for
product lines are documented à e.g. feature models.
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28. EffecIveness of
RE Technologies
• Lastly, the ulImate impact of RE research depends on how relevant
the results are to industry’s short- and long- term needs. So far,
there has been surprisingly lible evaluaIon as to how well RE
research results address industry problems.
• PracIIoners need hard evidence that a new technology is cost-
effecIve, in order to jusIfy the overhead, in training and in process
documentaIon, of changing their development processes.
• In parIcular, pracIIoners would benefit greatly from empirical
studies that assess the costs and benefits of using proposed
technologies, assess the scope of problems to which research
results can feasibly be applied, and compare the effecIveness of
compeIng technologies.
• There have been a few studies along these lines.
à What are the problems here for those studies?
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29. EffecIveness of
RE Technologies
• Lastly, the ulImate impact of RE research depends on how relevant
the results are to industry’s short- and long- term needs. So far,
there has been surprisingly lible evaluaIon as to how well RE
research results address industry problems.
• PracIIoners need hard evidence that a new technology is cost-
effecIve, in order to jusIfy the overhead, in training and in process
documentaIon, of changing their development processes.
• In parIcular, pracIIoners would benefit greatly from empirical
studies that assess the costs and benefits of using proposed
technologies, assess the scope of problems to which research
results can feasibly be applied, and compare the effecIveness of
compeIng technologies.
• There have been a few studies along these lines.
à What are the problems here for those studies?
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30. Five recommendaIons
… that the RE community could take immediate acIon on, to
start improving the maturity of current requirements
technologies:
• Researchers should work with pracIIoners.
• RE researchers should work with other SE researchers and
pracIIoners, to establish stronger links between their
respecIve arIfacts.
• RE researchers should not neglect evaluaIon and empirical
research.
• Industrial organizaIons should provide (saniIzed)
industrial-strength project data to researchers.
• RE researchers and pracIIoners, together, should establish
repositories of RE arIfacts.
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