183 research outputs found
Large-scale Complex IT Systems
This paper explores the issues around the construction of large-scale complex
systems which are built as 'systems of systems' and suggests that there are
fundamental reasons, derived from the inherent complexity in these systems, why
our current software engineering methods and techniques cannot be scaled up to
cope with the engineering challenges of constructing such systems. It then goes
on to propose a research and education agenda for software engineering that
identifies the major challenges and issues in the development of large-scale
complex, software-intensive systems. Central to this is the notion that we
cannot separate software from the socio-technical environment in which it is
used.Comment: 12 pages, 2 figure
COORDINATION AND CONTROL OF LARGE-SCALE COMPLEX IT SYSTEMS: AN INTERDISCIPLINARY REVIEW OF THE LITERATURE
Since the emergence and widespread adoption of computer networks in the 1990s, developed societies have grown increasingly dependent on complex software-intensive systems. Such systems underpin business-critical applications in domains ranging from health care and financial markets to manufacturing and defense, where failure would have profound social and economic consequences Sommerville et al. (2012). These large-scale complexes IT systems are usually created and evolved dynamically through the integration of independently built and controlled heterogeneous components
Academic Cloud Computing Research: Five Pitfalls and Five Opportunities
This discussion paper argues that there are five fundamental pitfalls, which
can restrict academics from conducting cloud computing research at the
infrastructure level, which is currently where the vast majority of academic
research lies. Instead academics should be conducting higher risk research, in
order to gain understanding and open up entirely new areas.
We call for a renewed mindset and argue that academic research should focus
less upon physical infrastructure and embrace the abstractions provided by
clouds through five opportunities: user driven research, new programming
models, PaaS environments, and improved tools to support elasticity and
large-scale debugging. The objective of this paper is to foster discussion, and
to define a roadmap forward, which will allow academia to make longer-term
impacts to the cloud computing community.Comment: Accepted and presented at the 6th USENIX Workshop on Hot Topics in
Cloud Computing (HotCloud'14
Cloud Migration: A Case Study of Migrating an Enterprise IT System to IaaS
This case study illustrates the potential benefits and risks associated with
the migration of an IT system in the oil & gas industry from an in-house data
center to Amazon EC2 from a broad variety of stakeholder perspectives across
the enterprise, thus transcending the typical, yet narrow, financial and
technical analysis offered by providers. Our results show that the system
infrastructure in the case study would have cost 37% less over 5 years on EC2,
and using cloud computing could have potentially eliminated 21% of the support
calls for this system. These findings seem significant enough to call for a
migration of the system to the cloud but our stakeholder impact analysis
revealed that there are significant risks associated with this. Whilst the
benefits of using the cloud are attractive, we argue that it is important that
enterprise decision-makers consider the overall organizational implications of
the changes brought about with cloud computing to avoid implementing local
optimizations at the cost of organization-wide performance.Comment: Submitted to IEEE CLOUD 201
On the engineering of systems of systems: key challenges for the requirements engineering community!
Software intensive systems of the future will be ultra large-scale systems of systems. Systems of Systems Engineering focuses on the interoperation of many independent, self-contained constituent systems to achieve a global need. The scale and complexity of systems of systems possess unique challenges for the Requirements Engineering community. Current requirements engineering techniques are inadequate in addressing these challenges and new concepts, methods, techniques, tools and processes are required. This paper identifies some immediate key challenges for the Requirements Engineering community that need to be scoped and describes some road-mapping activities that aim to address these challenges
Permissive Controller Synthesis for Probabilistic Systems
We propose novel controller synthesis techniques for probabilistic systems
modelled using stochastic two-player games: one player acts as a controller,
the second represents its environment, and probability is used to capture
uncertainty arising due to, for example, unreliable sensors or faulty system
components. Our aim is to generate robust controllers that are resilient to
unexpected system changes at runtime, and flexible enough to be adapted if
additional constraints need to be imposed. We develop a permissive controller
synthesis framework, which generates multi-strategies for the controller,
offering a choice of control actions to take at each time step. We formalise
the notion of permissivity using penalties, which are incurred each time a
possible control action is disallowed by a multi-strategy. Permissive
controller synthesis aims to generate a multi-strategy that minimises these
penalties, whilst guaranteeing the satisfaction of a specified system property.
We establish several key results about the optimality of multi-strategies and
the complexity of synthesising them. Then, we develop methods to perform
permissive controller synthesis using mixed integer linear programming and
illustrate their effectiveness on a selection of case studies
Information requirements for enterprise systems
In this paper, we discuss an approach to system requirements engineering, which is based on using models of the responsibilities assigned to agents in a multi-agency system of systems. The responsibility models serve as a basis for identifying the stakeholders that should be considered in establishing the requirements and provide a basis for a structured approach, described here, for information requirements elicitation. We illustrate this approach using a case study drawn from civil emergency management
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