|
CREWS Reports 1998
Peter Haumer, Patrick Heymans, Matthias Jarke, and Klaus Pohl
in
Proceedings of the Fourth IEEE International Symposium on Requirements Engineering
(RE'99), 7-11 June 1999, University of Limerick, Ireland.
Abstract
Requirements Engineering (RE) investigates the impact of a future-oriented change vision,
but the move towards this vision must consider a context heavily shaped by the past. As RE
be-comes a continuous process throughout the system lifecycle, it must achieve an
effective combination of envisionment and traceability. In this paper, we describe a
scenario-based solution to this problem which is based on an integration of five
ingredients: (a) the persistent capture of context in the form of real world scenes
captured in multimedia; (b) formal agent-oriented model-ling with a semantics that allows
distributed interactive animation; (c) message trace diagrams as a medium for exchanging
animation test cases and traces; (d) a goal model to control and record the RE process;
and (e) a process-integrated tool environment to ensure method-guidance and traceability
with as little effort as possible. In addition to the basics of our approach, we also
describe its prototypical implementation in the CREWS-EVE environment and demonstrate its
usefulness with examples from a case study in the production industry.
A. G. Sutcliffe and S. Minocha
Abstract
Few RE methods address analysis of socio-technical system requirements. This paper
describes a method for analysing dependencies between computer systems and
users/stakeholders in the operational environment. Domain scenarios describing the system
and its context are used to create an environment model based on the i* notation. The
dependencies between inbound and outbound events between the system and its usage
environment are analysed to elicit requirements to process system input or generate system
output. Coupling metrics are applied to these events to assess the degree of dependencies
between the system and the users. High level requirements are suggested to deal with
different types of organisational design. The method is illustrated with a case study of a
service engineer support system.
A. G. Sutcliffe, J. Galliers and S. Minocha
in
Fourth IEEE International Symposium on Requirements Engineering (RE'99)
Abstract
This paper reports a method of assessing the implications for human error on
system requirements, a topic not usually considered during requirements engineering (RE)..
In our previous work, we proposed a taxonomy of influencing factors that might contribu te
to human error. This paper takes the taxonomy and elaborates it to suggest generic
requirements to deal with problems in different layers of the taxonomy. Components of the
taxonomy are combined into a causal model for error, represented as a Bayesian Belief Net
(BBN). BBNs model the error influences arising from user knowledge, ability, and the task
environment. These are combined with factors describing the complexity of action and user
interface quality in scenarios of projected system usage. The BB N model predicts
probabilities of slips and mistakes. These are assessed according to action types in the
scenario to suggest generic requirements to prevent the error or to deal with its
consequences. The method is illustrated by a service engineer suppo rt system application.
A. G. Sutcliffe and S. Minocha
in
Proceedings of the 11th Conference on Advanced Information Systems Engineering, CAiSE'99,
Heidelberg, Germany, June 14-18, 1999.
Abstract
Few methods address analysis of socio-technical system requirements. This paper describes
a method for analysing dependencies between computer systems and users/stakeholders in the
operational environment. Domain scenarios describing the system and its co ntext are used
to create an environment model based on the i* notation. A method is proposed to define
business organisational relationships, according to the coupling between agents determined
by types of event flows between them, and secondly, by operat ionalising transaction cost
theory to obtain an a priori view of relationships according to the market context for a
client and supplier. Coupling metrics are applied to assess the degree of dependencies
between the system and the users. High-level requir ements are suggested to deal with
different types of organisational design. The method is illustrated with a case study of a
service engineer support system.
Julia Galliers, Shailey Minocha and Alistair Sutcliffe
submitted to
Special Issue on 'User Interface Design for safety-Critical Systems' of the Journal of
Transactions of Computer Human Interaction (TOCHI) - currently under review
Abstract
This paper describes a method of assessing the implications for human error on user
interface design of safety-critical software. In previous work we have proposed taxonomy
of influencing factors that contribute to error. In this paper, components of the taxonomy
are combined into a mathematical and causal model for error, represented as a Bayesian
Belief Net (BBN). The BBN quantifies error influences arising from user knowledge, ability
and the task environment, combined with factors describing the compl exity of user action
and user interface quality. The BBN model predicts probabilities of different types of
error, slips and mistakes, for each component action of a task involving user-system
interaction. We propose an Impact Analysis Method that involve s running test scenarios
against this causal model of error in order to determine those user actions that are prone
to different types of error. Applying the proposed method will enable the designer to
determine the combinations of influencing factors an d their interactions that are most
likely to influence human error. Finally we show how such scenario-based causal analysis
can be useful as a means of focusing on specifically relevant guidelines for safe user
interface (UI) design. In the paper the prop osed method is demonstrated through a case
study of an operator performing a task using the control system for a laser
spectrophotometer.
Mustapha Tawbi, Carine Souveyet
appeared in
Proceedings of MFPE'99: Second International Workshop on The Many Facets of Process
Engineering - From Theory to Practice, Tunis, Tunisia, 12-14 May 1999.
Abstract
The approach CREWS-L'Ecritoire developed within the CREWS project tightly couples goal
modelling and scenario authoring to elicit system requirements. The paper focuses on the
process aspect of the approach. It presents the process model as composed of a map and
associated guidelines. The map is a directed graph of intentions and strategies to flow
from one intention to another. Intention achievement is supported by guidelines. The
process model and its enactment mechanism have been implemented in a software tool called
l'ECRITOIRE. The paper presents the process map of the approach CREWS-l'ECRITOIRE and
illustrates its use with an example to elicit the requirements of a system to recycle
objects.
C. Rolland, G. Grosz, R. Kla
In
Proceedings of the Fourth IEEE International Symposium on Requirements Engineering
(RE'99), 7-11 June 1999, University of Limerick, Ireland.
Abstract
In the context of Requirements Engineering (RE), both goal-driven approaches and
scenario-based approaches have proven useful for eliciting, justifying and validating
system requirements. In order to overcome some of the deficiencies and limitations of
these approaches when used in isolation, proposals have been made to couple goals and
scenarios together. The CREWS -L'Ecritoire approach advocates for a bi-directional
coupling allowing movement from goals and scenarios and vice-versa.
The paper reports on an experimentation of the CREWS-L'Ecritoire approach on a large scale
business process re-engineering project conducted in the context of an electricity supply
and distribution company. The focus is on a set of issues that we found important and that
we believe are not specific to our approach. We considered three kinds of issues, those
which are found in goal-driven approaches, those in scenario-based approaches, and those
specific to goal-scenario coupling. In this paper, we devote a specific attention to the
third kind of issues and assess the extent to which the goal-scenario coupling helps to
resolve the first two kinds of issues.
C. Ben Achour, C. Rolland, N.A.M. Maiden, C. Souveyet
in
Proceedings of the Fourth IEEE International Symposium on Requirements Engineering
(RE'99), 7-11 June 1999, University of Limerick, Ireland
Abstract
This paper presents results from the first of two empirical studies which examine the
effectiveness of guidelines for use case authoring. The ESPRIT 21.903 CREWS long-term
research project has developed style and content guidelines for authoring use cases for
requirements acquisition and validation. The effectiveness of these guidelines has been
evaluated under different conditions. Results indicate that: i. the authoring guidelines
improve the overall quality of the use case prose, ii the different guidelines work
differently and with different levels of efficiency, and iii use cases are never entirely
correctly written; thus, they can be systematically corrected. The paper details a
qualitative and quantitative comparison between guided and non-guided use case authoring.
It outlines lessons learned and implications for the CREWS software tools design.
Patrick Heymans and Eric Dubois
appeared in
Requirements Engineering Journal, Vol. 3, No. 3-4, 1998.
Abstract
Developing complex, safety critical systems requires precise, unambiguous specification of
requirements. A formal specification language is thus well suited to this task. Formal
specification languages require, but also exacerbate, the need for tools. In particular,
tools should support the elaboration (how to build the formal specification?) and the
validation (how to check the adequacy of the specification towards the informal needs of
the various stakeholders?).
This paper focuses on the language Albert II, a formal language designed for the purpose
of ex-pressing requirements for distributed real-time systems. It presents two
contributions supporting its use. The first contribution aims at improving the elaboration
process by providing a method for constructing an Albert II description from scenarios
expressing the stakeholders' requirements. These are represented through Message Sequence
Charts extended to deal with composite systems. The second contribution takes the form of
a requirements validation tool (a so-called animator) that the stakeholders can use
interactively and cooperatively in order to explore different possible behaviours (or
instance-level scenarios) of the future system. These behaviours are automatically checked
against the formal requirements specification.
N.A.M. Maiden, M. Cisse, H. Perez, D. Manuel
appeared in
Fourth International Workshop on Requirements Engineering: Foundation for Software Quality
(RESFQ), Pisa, Italy, June 8th-9th, 1998.
Abstract
This paper proposes a pattern language for socio-technical system design to inform
validation of system requirements. The development of this language takes inspiration from
Alexander's pattern language for building design in architecture. It identifies different
types of patterns which fulfil different roles in the requirements engineering process.
This pattern-based validation approach has been operationalised in the CREWS-SAVRE
software prototype. CREWS-SAVRE applies patterns to both scenarios and requirements
documents to detect missing and incorrect system requirements, as well as to recommend new
requirements which can improve the design of the socio-technical system.
Peter Haumer, Patrick Heymans, Klaus Pohl
Abstract
Scenarios are widely used in industry to support requirements elicitation and validation.
Tool support is a prerequisite for effective use and management of scenarios. In this
paper we propose to integrate two scenario-based techniques developed in the ESPRIT
Project CREWS. One supports the elicitation of a goal model from real-world scenarios. The
other allows to validate a formal system specification by playing instance-level scenarios
against it. Interestingly, the two of them complement each other in various respects. We
outline the benefits obtained by integration and present how we performed it at the
conceptual and technical levels. The resulting integrated environment has been validated
on a small case study in the manufacturing domain.
C. Rolland, C. Souveyet, C. Ben Achour.
appeared in
IEEE Transactions on Software Engineering: Special Issue on Scenario Management, Vol. 24,
No. 12, 1998.
Abstract
Even though goal modelling is an effective approach to requirements engineering, it is
known to present a number of difficulties in practice. The paper discusses these
difficulties and proposes to couple goal modelling and scenario authoring to overcome
them. Whereas existing techniques use scenarios to concretise goals, we use them to
discover goals. Our proposal is to define enactable rules which form the basis of a
software environment to guide the requirements elicitation process through interleaved
goal modelling and scenario authoring. The focus of the paper is on the discovery of goals
from scenarios. The discovery process is centred around the notion of a Requirement Chunk
(RC) which is a pair <Goal, Scenario>. RCs enter into AND, OR and Refinement
relationships with each other. The enactable rules support the discovery of RCs and of
their inter-relationships.The result is an easy to use, flexible, scaleable and automated
support for requirements elicitation that produces benefits outside requirements gathering
: system requirements are tracked from business goals, alternative design options are
explicitly discussed and tracked, requirements are expressed and concretised through
scenarios at different levels of abstraction. The approach presented in the paper is
illustrated with the ATM example.
Camille Ben Achour
appeared in the
Proceedings of the Natural Language and Information Systems (NLIS'98) Workshop 28th August
1998, Vienna, Austria, 1998.
Abstract
Since a few years, scenarios have gained in popularity in Requirements Engineering.
Textual scenarios are narrative descriptions of flows of actions between agents. They are
often proposed to elicit, validate or document requirements. The CREWS experience has
shown that the advantage of scenarios is their easiness of use, and that their
disadvantage stands in the lack of guidelines for 'quality' authoring. In this article, we
propose guidance for the authoring of scenarios. The guided scenario authoring process is
divided into two main stages: the writing of scenarios, and the correcting of scenarios.
To guide the writing of scenarios, we provide style and contents guidelines referring to a
conceptual and a linguistic model of scenarios. Our assumption is that scenarios written
in conformance to these guidelines can be semi-automatically analysed. Else, to guide the
correcting of scenarios, we propose a set of enactable rules. These rules aim at the
clarification, completion and conceptualisation of scenarios, and help the scenario author
to improve his scenarios until acceptable quality in the terms of the former scenario
models.
S. Nurcan.
appeared in
Telecooperation Conference of the 15th IFIP World Computer Congress 1998, 31 August-4
September 1998, Vienna, Austria, 1998.
Abstract
Computer Supported Cooperative Work (CSCW) studies the possibilities and effects of
technological support for agents involved in cooperative work processes. Many technologies
dedicated to cooperative work environments such us cooperative requirements engineering or
cooperative information systems have emerged in the past decade. For many organisations,
structured and unstructured cooperative activities coexist in work processes and must be
managed in the final solution. It is necessary to emphasise the specificities of these
processes in order to take them into account as soon as possible during design. This work
presents a model which is a synthesis of the concepts we believe essential for cooperative
work place analysis.
C. Ben Achour, C. Rolland, C. Souveyet.
appeared in
Proceedings of the REFSQ'98 Workshop on requirements engineering foudnation for software
quality, Pisa, June 1998.
Abstract
The study and practice of scenarios raise the question of managing the combinatorial
explosion of the number of scenarios. This article proposes a set of relationships to
organise a collection of scenarios. Three types of relationships are proposed : OR, AND,
and Refinement. These relationships are generic and can be used to manage any kind of
scenarios. Using them leads to build a structured network of scenarios. In addition, to
guide the construction of 'quality' networks of scenarios, the paper presents quality
properties and heuristic guidelines. The approach is illustrated by the CREWS approach.
M. Tawbi, C. Souveyet, C. Rolland.
submitted to the
Information Software and Technology Journal.
Abstract
The paper presents 'L'ECRITOIRE' a tool which supports the goal-scenario based approach
for requirements engineering developed within the CREWS project. The approach tightly
couples goal modeling and scenario authoring to elicit system requirements The approach is
supported by guidelines encapsulated in modular method chunks that are assembled in
different ways called method paths. A method path is a situated 'good practice' of goal
modeling and scenario authoring. The paper presents one of the CREWS_l'ECRITOIRE method
paths and illustrates it use through a l'ECRITOIRE session.
V. Plihon, J. Ralyté, A. Benjamen, N.A.M. Maiden, A. Sutcliffe, E. Dubois, P. Heymans.
appeared in
Proceedings of the International Software Process Association's 5th International
Conference on Software Process (ICSP'98), Chicago, Illinois, USA, 14-17 June 1998.
Abstract
Despite the recent interest in scenarios, the development of new methods and tools for
Requirements Engineering integrating scenario based approaches has been limited. This
paper reports on four different processes developed from research undertaken as part of
the CREWS project which the authors believe will improve scenario use and make it more
systematic. Furthermore CREWS aims to integrate these approaches into a method for
scenario-based requirements engineering. To achieve this objective and be able to include
existing approaches such as use case analysis we develop a component based approach which
reflects a shift towards a reuse-centric approach to method engineering. The paper
presents CREWS method and meta-method knowledge through the implementation of an SGML
database to store, retrieve and dynamically compose chunks of CREWS processes.
C. Rolland.
appeared in
Proceedings of the 20th International Conference on Software Engineering ICSE'98, Kyoto,
Japan, April 1998.
No abstract.
S. Si Saïd, C. Rolland.
appeared in
Proceedings of the Eight European - Japanese Conference on Information Modelling and
Knowledge Bases. May 25-29, Vamala, Finland, 1998.
Abstract
Guidance plays a crucial role in requirements engineering (RE) as this task is both ill
defined and highly intellectual. The guidance approach presented in this paper consists of
supporting requirements engineers by a collection of enactable guidelines embodied in a
computer environment. The key characteristics of the approach is its intention
orientation. Guidance can be provided once the intention to be achieved has been elicited.
Two kinds of guidance are proposed, step and flow guidance. The former supports the
fulfilment of intentions whereas the latter helps in intention elicitation. The paper
presents the two types of guidance, the corresponding guidelines and the Computer Aided
Requirements Engineering (CARE) environment which supports their enactment. The approach
is illustrated with the CREWS requirements engineering approach which elicits requirements
through interleaved goal modelling and scenario authoring.
C. Souveyet, M. Tawbi.
appeared in
Proceedings of the 9th International DEXA Conference on Database and Expert Systems
Applications, Vienna, Austria, August 1998.
Abstract
A reuse based approach to construct software tool supporting a specific method built
"on the fly" is presented in this paper. Its originality is to apply a process
view on the reusable component which is either method chunk or software chunk. Our process
view leads to construct method and software tool by assembling chunks. Chunks which are
either method or software ones can be assembled in different ways depending on the
situation of the project at hand. One of these ways is called a method or a software path.
Our aim is to support the construction of a specific method path and its use in a CASE
environment. The paper focuses on (i) the description of a process centred approach for
software tool development (ii) its use in the development of the tool
"l'écritoire" and (iii) the support of software engineer through a set of
guidelines.
C. Rolland.
appeard in
Proceedings of the 10th International Conference CAiSE'98, B. Lecture Notes in Computer
Science 1413, Pernici, C. Thanos (Eds), Springer. Pisa, Italy, June 1998.
Abstract
The paper proposes a faceted framework to understand and classify issues in system
development process engineering. The framework identifies four different but complementary
view-points. Each view allows us to capture a particular aspect of process engineering.
Inter-relationships between these aspects allow us to show the influence that one aspect
has on another. In order to study, understand and classify a particular aspect of process
engineering in its diversity we associate a set of facets with each aspect. The paper uses
the framework to raise questions, problems and research issues in the field.
Peter Haumer, Klaus Pohl, Klaus Weidenhaupt, Matthias Jarke
appeared in
Scenario-Based System Development (A mini-track within the Emerging Technologies Track of
the Thirty-Second Annual Hawaii Inter-national Conference on Systems Sciences (HICSS-32),
Maui, HI, January 5-8, 1999.
Abstract
When defining a new system, the history and functionality of the system to be replaced
should be considered. Thereby making the same failure twice or neglecting important system
functionality can be avoided. The requirements of the existing system are typically
elicited by analysing concrete system usage scenarios. The requirements are typically
being represented using con-ceptual models. To establish conceptual models of high
quality, reviewing the models is common practice. The problem faced with when reviewing
conceptual models, is that the reviewer can not assess and therefore understand the basis
(concrete system usage) on which the conceptual models where build.
In this paper, we present an approach to overcome this problem. We argue to establish
extended traceability, by recording concrete system usage scenarios using rich media (e.g.
video, speech, graphic) and interrelating the recorded observations with the con-ceptual
models. We discuss the principle improvements for reviewing processes result-ing from the
extended traceability and illustrate the advantages with excerpts of the case study
performed in a mechanical engineering company.
Peter Haumer, Klaus Pohl, Klaus Weidenhaupt
appeared in
IEEE Transactions on Software Engineering, Vol. 24, No. 12, Special Issue on Scenario
Management, December 1998.
Abstract
Scenarios are an excellent means for eliciting and validating requirements. In contrast to
a requirements specification which defines the requirements for the future system at a
con-ceptual level (i.e. class or type level), a scenario represents a concrete example of
current or future system usage. In early RE phases, scenarios are used to support the
definition of the main goals (high level requirements) to be achieved by the new system.
In many cases, most of those goals can be elicited by observing, documenting and analysing
scenarios about current system usage, i.e. the new system must often fulfil most of the
functional and non-functional goals of the existing system.
To support the elicitation and validation of the goals achieved by the existing system we
propose to capture current system usage using rich media (e.g. video, speech, pictures
etc.) and to interrelate those observations with the goal definitions. More precisely, we
propose to relate the parts of the observations which have caused the definition of a goal
or against which a goal was validated with the corresponding goal(s). Thereby a
fine-grained interre-lation between the conceptual goal model and the recorded
observations is established. These interrelations provide the basis for explaining and
illustrating a goal model to, e.g., untrained stakeholders and/or new team members, and
thereby improving a common understanding of the goal model; detecting, analysing and
resolving a different interpretation of the observations; comparing different observations
using computed goal annotations based on the inter-relations; refining or detailing a goal
model during later process phases.
Eric Dubois, Eric Yu, Michael Petit.
to appear in
Proc. of IWSSD9, Isobe, Japan. April 1998.
Abstract
In this paper, we consider three distinct and connected modelling activities at the
Requirements Engineering (RE) level. Within the context of reactive systems, we suggest
how these three activities can be supported by the use of appropriate formal languages,
namely Kaos, Albert and Timed Automata. The i* framework is used for linking the various
formal models and for providing a "high level'' model in terms of which
organizational issues are captured. A small process control example is used to illustrate
the proposed approach.
Luc Claes
appeared in
Component-based Information Systems Engineering Workshop (CAiSE'98), Pisa, June 1998.
Abstract
We describe a generic software environment intended to assist the construction of
applications by the composition of reusable components. Two classes of components (and
their related systems) are clearly distinguished: operational components (or components in
the 'classical', technological sense) and descriptive components, encapsulating meta-data
about, amongst others, their operational counterparts. Components are viewed as actors in
a communicating entities system. Communications capabilities and needs are abstracted as a
set of layers, each layer denoting a delimited conventions set and satisfying or dictating
functional requirements. A case study describes how we are using - or intend to use - our
models in real life applications. The selected case consists in the interconnection of
two, otherwise incompatible, CASE tools.
P. Haumer, K. Pohl, K. Weidenhaupt
appeared in
Fourth International Workshop on Requirements Engineering: Foundation for Software Quality
(RESFQ), Pisa, Italy, June 8th-9th, 1998.
Abstract
The role of the requirements engineer is to establish a complete consistent and
unambiguous requirements specification which defines the requirements at a conceptual
level. Many traditional modelling approaches from Structured Analysis, to UML-based
methods supporting him in this task neglect the use of concrete examples about current or
future system usage.
In this paper, we present so called Abstraction Guides which assist the requirements
engineer in establishing and applying an interrelating structure between conceptual models
and persistent recorded usages of existing systems called Real World Scenes (RWS). This
structure is used to improve traceability, understandability and negotiation of conceptual
models. We show how Abstraction Guides define support for eliciting requirements from RWS,
vali-dating requirements against RWS, explanation of conceptual models, and comparing
scenes and models.
C. Ben Achour
appeared in
Proceedings of the Eighth European - Japanese Conference on Information Modelling and
Knowledge Bases. May 25-29, Vamala, Finland.
Abstract
Since a few years, scenario based requirements engineering approaches have gained in
popularity. Textual scenarios are narrative descriptions of flows of actions between
agents. They are often proposed to elicit, validate or document requirements. The CREWS
experience has shown that the advantage of scenarios is their easiness of use, and that
their disadvantage stands in the lack of guidelines for authoring. In this article, we
propose guidance for the authoring of scenarios. The guided scenario authoring process is
divided into two main stages : the writing of scenarios, and the correcting of scenarios.
To guide the writing of scenarios, we provide style and contents guidelines referring to a
conceptual and a linguistic model of scenarios. To guide the correcting of scenarios, we
propose a set of enactable rules. These rules aim at the clarification, completion and
conceptualisation of scenarios, and help the scenario author to improve his scenarios
until acceptable quality in the terms of the former scenario models. The paper presents
both style / contents guidelines, and correction rules, and illustrates them with the
London Ambulance Service example.
K. Lyytinen, P. Martiin, J.-P. Tolvanen, M. Jarke, K. Pohl, K. Weidenhaupt
appeared in
Proceedings of the Eight annual Workshop on Information Technologies and Systems WITS'98.
Computer Science and Information Systems Reports TR-19, University of Jyväskylä,
Finnland.
Abstract
In current CASE environments a user has to choose between efficient computerized sup-port
using a fixed methodical framework which may not fit his situation, or the freedom to do
what seems appropriate in the given circumstance, but at the cost of losing efficient
technological support. In this paper we examine adaptable metamodel based environments as
a means to resolve this dilemma. Metamodel based environments provide means to rep-resent
and modify knowledge about development products, processes, and representation schemes to
improve the designer-task fit. Metamodel based adaptability is not a new inno-vation. Yet,
earlier metamodel based approaches have tended to create islands of automa-tion that focus
on improving adaptability either in ontologies, notations, or process defini-tions. The
paper applies a framework which integrates these aspects and thereby increases environment
adaptability that covers a wider spectrum of development situations. The metalevel based
integration is demonstrated by describing how two metamodel based tools focusing on
different aspects of adaptability can be integrated. The resulting integrated environment
encompasses both product (ontology/notation) and process aspects.
R. Dömges, K. Pohl, K. Schreck
appeard in
CAiSE’98 Conference on Advanced Information Systems Engineering, June, 1998
Abstract
Traceability is a prerequisite for developing high quality (software) systems. Recording
and maintaining all available information is too labour intensive and thus by far too
expensive. A project-specific definition of the trace information to be recorded and the
method fragments (so called trace fragments) to be executed for recording the information
provides a solution for this problem. But the amount of traces to be recorded does not
only vary from project to project. It also varies between project phases and even within a
project phase. As a consequence project-specific trace fragments need to be adapted
according to the actual project phase. In this paper we propose a model-based filter
mechanism to significantly reduce the required effort to adapt trace fragments. By
defining appropriate filters the project manager is able to (dynamically) adapt the
project-specific trace fragments to the actual needs. We present an example to highlight
the benefits of the approach and discuss possible extensions.
K. Pohl, K. Weidenhaupt, R. Dömges, P. Haumer, M. Jarke, R. Klamma
accepted for
ACM Transactions on Software Engineering and Methodology, 1999.
Abstract
Research in process-centered environments (PCEs) has focused on project management support
and has neglected method guidance for the engineers performing the (software) engineering
process. It has been dominated by the search for suitable process modeling languages and
enactment mechanisms. The consequences of the process orientation on the computer-based
engineering environments, i.e. the interactive tools used during process performance, have
been studied much less. In this paper, we present the PRIME (PRocess-Integrated Modeling
Environments) framework which empowers method guidance through process-integrated tools.
In contrast to the tools of PCEs, the process-integrated tools of PRIME adjust their
behavior according to the current process situation and the method definitions.
Process-integration of PRIME tools is achieved through the definition of tool models; the
integration of the tool models and the method definitions; the interpretation of the
integrated environment model by the tools, the process-aware control integration
mechanism, and the enactment mechanism; the synchronization of the tools and the enactment
mechanism based on a comprehensive interaction protocol. We sketch the implementation of
PRIME as reusable implementation framework which facilitates the realization of
process-integrated tools as well as the process-integration of legacy tools. We define a
six-step procedure for building a PRIME-based process-integrated environment (PIE) and
illustrate how PRIME facilitates change integration on an easy-to-adapt modeling level.
Following the six-step procedure we have implemented two process-integrated environments
(PRIME-CREWS and TECHMOD) which have been applied in small case studies.
A.G. Sutcliffe, N.A.M. Maiden, S. Minocha, D. Manuel
appeared in
IEEE Transactions on Software Engineering: Special Issue on Scenario Management, Vol. 24,
No. 12, 1998.
Abstract
Scenarios have been advocated as a means of improving requirements engineering yet few
methods or tools exist to support scenario based RE. The paper reports a method and
software assistant tool for scenario-based RE that integrates with use case approaches to
object oriented development. The method and operation of the tool are illustrated with a
financial system case study. Scenarios are used to represent paths of possible behaviour
through a use case and these are investigated to elaborate requirements. The method
commences by acquisition and modelling of a use case. The use case is then compared with a
library of abstract models that represent different application classes. Each model is
associated with a set of generic requirements for its class, hence, by identifying the
class(es) to which the use case belongs, generic requirements can be reused. Scenario
paths are automatically generated from use cases, then exception types are applied to
normal event sequences to suggest possible abnormal events resulting from human error.
Generic requirements are also attached to exceptions to suggest possible ways of dealing
with human error and other types of system failure. Scenarios are validated by rule-based
frames which detect problematic event patterns. The tool suggests appropriate generic
requirements to deal with the problems encountered. The paper concludes with a review of
related work and a discussion of the prospects for scenario based RE methods and tools.
A.G. Sutcliffe
accepted for publication in the
Requirements Journal, 1998
Abstract
A method for scenario based requirements engineering is described. The method uses two
types of scenario,structure models of the system context and scripts of system usage.
Amodelling language is reported for describing scenarios, and heuristics aregiven to cross
check dependencies between scenario models and the requirements specification. Heuristics
aregrouped into several analytic treatments that investigate correspondencesbetween users'
goals and system functions; input events and systemprocesses to deal with them; system
outputand its destination in the scenario model, and acceptability analysis ofsystem
output for different stakeholders. The method is illustrated with acase study taken from
the London Ambulance Service report. The prospectsfor scenario based RE and relatedwork
are discussed.
A.G. Sutcliffe, A. Economou, P. Markis
accepted for publication in the
Requirements Engineering Journal, 1998.
Abstract
A case study of requirements engineering practice is reported. The application, a decision
support system for the Greek Ministry of Health, was investigated by studying the process
of requirements analysis through to design and implementation. A usability analysis was
then conducted on the designed system with the users. Several usability problems were
discovered, and interviews uncovered further problems with the system that could be
attributed to failure in requirements engineering. Even though requirements were
explicitly stated and the system was an evolution from an existing legacy system,
functionality was defective and usability was poor. The client's prime concern for
redeveloping the system was to improve usability; unfortunately communications problems in
the RE process meant that the developers did not appreciate this. The implications for RE
methods and understanding the RE process are discussed.
C. Rolland, V. Plihon, Y. Ralyté
appeared in
Proceedings of the 10th International Conference CAiSE'98, B. Lecture Notes in Computer
Science 1413, Pernici, C. Thanos (Eds), Springer, pp. 191. Pisa, Italy, June 1998.
Abstract
There has been considerable recent interest in scenarios for accompanying many of the
various activities occurring in the development life cycle of computer based systems.
Besides the integration of scenarios in methods such as Objectory and software tools such
as Rationale Rose has proven useful and successful. Consequently, there is a demand for
adapting existing methods to support specific design activities using scenario based
approaches. The view developed in this paper is that scenario based approaches should be
looked upon as reusable components. Our concern is therefore twofold : first, to represent
scenario based approaches in a modular way which eases their reusability and second, to
specify the design context in which these approaches can be reused in order to facilitate
their integration in existing methods. The paper concentrates on these two aspects,
presents an implementation of our proposal using SGML to store available scenario based
approaches in a multimedia hypertext document and illustrates the retrieval of components
meeting the requirements of the user by the means of SgmlQL queries.
S. Nurcan, G. Grosz, C. Souveyet
appeared in
Proceedings of the 10th International Conference CAiSE'98, B. Lecture Notes in Computer
Science 1413, Pernici, C. Thanos (Eds), Springer, pp. 339-362. Pisa, Italy, June 1998.
Abstract
Business Process (BP) improvement and alike require accurate descriptions of the BPs. We
suggest to describe BPs as use case specifications. A use case specification comprises a
description of the context of the BP, the interactions between the agents involved in the
BP, the interactions of these agents with an automated system supporting the BP and
attached system internal requirements. Constructing such specifications remains a
difficult task. Our proposal is to use textual scenarios as inputs, describing fragments
of the BP, and to guide, using a set of rules, their incremental production and
integration in a use case specification also presented in a textual form. The paper
presents the structure of a use case, the linguistic approach adopted for textual
scenarios analysis and the guided process for constructing use case specifications from
scenarios along with the guidelines and support rules grounding the process. The process
is illustrated with a real case study borrowed to an Electricity Company.
N.A.M. Maiden
accepted for
Journal of Automated Software Engineering, 1998.
Abstract
This paper reports research into semi-automatic generation of scenarios for validating
system requirements. The research was undertaken as part of the ESPRIT IV 21903 'CREWS'
long-term research project. The paper presents the underlying theoretical models of domain
knowledge, computational mechanisms and user-driven dialogues needed for scenario
generation. It describes how CREWS draws on theoretical results from the ESPRIT III 6353
'NATURE'basic research action, that is object system models which are abstractions of the
fundamental features of different categories of problem domain. CREWS uses these models to
generate normal course scenarios, then draws on theoretical and empirical research from
cognitive science, human-computer interaction, collaborative systems and software
engineering to generate alternative courses for these scenarios. The paper describes a
computational mechanism for deriving use cases from object system models, simple rules for
use case composition, taxonomies of classes of exceptions which give rise to alternative
courses in scenarios, and a computational mechanism for generation of multiple scenarios
from use case specifications.
Alistair G. Sutcliffe and Shailey Minocha
appeared in
Fourth International Workshop on Requirements Engineering: Foundation for Software Quality
(RESFQ), Pisa, Italy, June 8th-9th, 1998.
Abstract
Scenarios have been advocated as an effective means of acquiring and validating
requirements as they capture examples and real world experiences that users can understand
[Potts et al. 1994]. Although scenarios have appeared in many diverse forms [Carroll
1995], most authors have used them for behavioural analysis, e.g. scenario scripts [Potts
et al. 1994] and use case scenarios [Jacobson et al. 1992, Graham 1996, Cockburn 1995].
More wider ranging views of scenarios as context settings for understanding
socio-technical systems have been proposed by Eason et al. [Eason et al. 1996] and Kyng
[Kyng 1995], but these too focus on user activity and system functionality, rather than
system qualities also generally referred to as non-functional requirements. This paper
explores the role scenarios could play in addressing non-functional requirements and
proposes a method for scenario generation and analysis for the purpose.
Colette Rolland, Camille Ben Achour
appeared in
Data & Knowledge Engineering Journal, Vol 25, N°1-2, pp. 125-160, (ed. P. Chen, R.P.
van de Riet), North Holland, Elsevier Science Publishers. March 1998.
Abstract
An approach for guiding the construction of use case specifications is presented. A use
case specification comprises contextual information of the use case, its change history,
the complete graph of possible pathways, attached requirements and open issues. The
proposed approach delivers a use case specification as an unambiguous natural language
text. This is done by a stepwise and guided process which progressively transforms initial
and partial natural language descriptions of scenarios into well structured, integrated
use case specifications. The basis of the approach is a set of linguistic patterns and
linguistic structures. The former constitutes the deep structure of the use case
specification whereas the latter corresponds to the surface structures. The paper presents
the use case model, the linguistic basis and the guided process along with the associated
guidelines and support rules. The process is illustrated with the automated teller machine
(ATM) case study.
| 
