Responsibility modelling for civil emergency planning

This paper presents a new approach to analysing and understanding civil emergency planning based on the notion of responsibility modelling combined with HAZOPS-style analysis of information requirements. Our goal is to represent complex contingency plans so that they can be more readily understood, so that inconsistencies can be highlighted and vulnerabilities discovered. In this paper, we outline the framework for contingency planning in the United Kingdom and introduce the notion of responsibility models as a means of representing the key features of contingency plans. Using a case study of a flooding emergency, we illustrate our approach to responsibility modelling and suggest how it adds value to current textual contingency plans

Responsibility modelling for civil emergency planning

This paper presents a new approach to analysing and understanding civil emergency planning based on the notion of responsibility modelling combined with HAZOPS-style analysis of information requirements. Our goal is to represent complex contingency plans so that they can be more readily understood, so that inconsistencies can be highlighted and vulnerabilities discovered. In this paper, we outline the framework for contingency planning in the United Kingdom and introduce the notion of responsibility models as a means of representing the key features of contingency plans. Using a case study of a flooding emergency, we illustrate our approach to responsibility modelling and suggest how it adds value to current textual contingency plans

Progressing problems from requirements to specifications in problem frames

One of the problems with current practice in software development is that often customer requirements are not well captured, understood and analysed, and there is no clear traceable path from customer requirements to software specifications. This often leads to a mismatch between what the customer needs and what the software developer understands the customer needs. In addition to capturing, understanding and analysing requirements, requirements engineering (RE) aims to provide methods to allow software development practitioners to derive software specifications from requirements. Although work exists towards this aim, the systematic derivation of specifications from requirements is still an open problem. This thesis provides practical techniques to implement the idea of problem progression as the basis for transforming requirements into specifications. The techniques allow us to progress a software problem towards identifying its solution by carefully investigating the problem context and re-expressing the requirement statement until a specification is reached. We develop two classes of progression techniques, one formal, based on Hoare’s Communicating Sequential Processes (CSP), and one semi-formal, based on a notion of causality between events. The case studies in this thesis provide some validation for the techniques we have developed

Scenario-based system architecting : a systematic approach to developing future-proof system architectures

This thesis summarizes the research results of Mugurel T. Ionita, based on the work conducted in the context of the STW15 - AIMES16 project. The work presented in this thesis was conducted at Philips Research and coordinated by Eindhoven University of Technology. It resulted in six external available publications, and ten internal reports which are company confidential. The research regarded the methodology of developing system architectures, focusing in particular on two aspects of the early architecting phases. These were, first the generation of multiple architectural options, to consider the most likely changes to appear in the business environment, and second the quantitative assessment of these options with respect to how well they contribute to the overall quality attributes of the future system, including cost and risk analysis. The main reasons for looking at these two aspects of the architecting process was because architectures usually have to live for long periods of time, up to 5 years, which requires that they are able to deal successfully with the uncertainty associated with the future business environment. A second reason was because the quality attributes, the costs and the risks of a future system are usually dictated by its architecture, and therefore an early quantitative estimate about these attributes could prevent the system redesign. The research results of this project were two methods, namely a method for designing architecture options that are more future-proof, meaning more resilient to future changes, (SODA method), and within SODA a method for the quantitative assessment of the proposed architectural options (SQUASH method). The validation of the two methods has been performed in the area of professional systems, where they were applied in a concrete case study from the medical domain. The SODA method is an innovative solution to the problem of developing system architectures that are designed to survive the most likely changes to be foreseen in the future business environment of the system. The method enables on one hand the business stakeholders of a system to provide the architects with their knowledge and insight about the future when new systems are created. And on the other hand, the method enables the architects to take a long view and think strategically in terms of different plausible futures and unexpected surprises, when designing the high level structure of their systems. The SQUASH method is a systematic way of assessing in a quantitative manner, the proposed architectural options, with respect to how well they deal with quality aspects, costs and risks, before the architecture is actually implemented. The method enables the architects to reason about the most relevant attributes of the future system, and to make more informed decisions about their design, based on the quantitative data. Both methods, SODA and SQUASH, are descriptive in nature, rooted in the best industrial practices, and hence proposing better ways of developing system architectures

Proceedings ICPW'07: 2nd International Conference on the Pragmatic Web, 22-23 Oct. 2007, Tilburg: NL

Proceedings ICPW'07: 2nd International Conference on the Pragmatic Web, 22-23 Oct. 2007, Tilburg: N

Formalisation and evaluation of focus theories for requirements elicitation dialogues in natural language

Requirements engineering is an important part of software engineering. It consists in defining the needs of users when building a new system. These needs may be functional, i.e., what service should the system be able to provide, as well as non-functional, i.e., under which constraints should the system operate. Errors in requirements may have disastrous effects in the rest of the software engineering process (Brooks 1995, p.199), since they would lead to the construction of a system of little interest to its users or would require expensive modifications to correct. Because requirements documents may be very large, errors are usually hard to detect manually. Computer support is therefore often beneficial for their analysis. This is made easier if requirements are expressed formally. However, this support must also be adapted to and be usable by people who are expressing their requirements. These people are usually not computer specialists and are not accustomed to use formal languages. It is therefore necessary to help them express their requirements. Numerous approaches, have been suggested as aids to the acquisition of requirements (Reubenstein 1990). Much less attention has been paid to the control of the dialogue taking place between the users and the system whilst using such frameworks (Bubenko et al. 1994). Frameworks for requirements acquisition are not normally accompanied by theories of the types of dialogue which they support. Our ability to develop sophisticated formal frameworks to analyse requirements makes this deficiency more acutely felt, since increases in formality are often accompanied by greater difficulty in understanding and using the frameworks (Robertson et al. 1989).Users write their requirements in more or less natural language. This is then translated into a formal language that can be interpreted by the elicitation module. This module works on the requirements and provide feedback. The translation process is then applied to convert feedback into more or less natural language. Different systems put different emphasis on the parts of that general architecture. Some are very good at natural language interpretation while others put more emphasis on analysing the requirements and providing feedback.Natural language approaches to requirements elicitation, put an emphasis on natural language interpretation (see section 1.2.1). In these approaches, users write their specifica¬ tion in a subset of natural language. The system then translates it into a formal notation. The main benefit provided by these approaches is the improvement in the ease of use of the system: natural language is the main means of communication for human beings and does not need to be learned. However, most of these approaches do not provide a dialogue well suited for the requirements elicitation process. Because they translate the natural lan¬ guage specification into a formal notation but do not provide guidance on how to write the specification in the first place, users are left in charge of writing correct requirements. If a mistake is made while writing the specification, it will simply be translated into the formal notation.In order to actively help users in the process of writing the requirements, the elicit¬ ation system must interact with them. The emphasis, here, is no longer on translating requirements, but on actively extracting them through a dialogue with users. This is useful, since the requirements elicitation process is complex, and offering guidance is a big help for users. Unfortunately, most of the approaches providing guidance expose their formal underlying frameworks directly to users (see section 1.2.2). In order to benefit from the guidance provided, users have to learn the idiosyncrasies of the system they use. The task of providing guidance is complicated by the fact that there are numerous ways of carrying out the requirements elicitation. Very little research has been done on how to organise best the elicitation process to provide effective guidance. An arbitrary choice could be made, but forcing users to adopt a predefined method is usually not possible as it would make the elicitation process very difficult to follow and understand. The system must therefore be able to adapt itself to various elicitation methods. On the other hand, it is necessary for the system to make choices in order to provide active guidance. A "least-commitment" strategy, such as asking users at every choice point what to do next, is not a useful approach (Ferguson et al. 1996).One way of offering guidance without restricting users too much is by communicating with them in natural language, and by using natural language constraints to inform the choices made by the system to select a guidance strategy. These constraints ensure that the system adopts a strategy that will guide users in a natural and understandable manner, by taking into account the current state of the dialogue. In other words, the system takes into account the current state of the specification to help users complete it, but the current state of the dialogue is the principal factor constraining what will be spoken about next. Using such an approach reduces some of the problems discussed above. The specification does not need to be immediately correct as it will be checked and reworked by the system. The formal framework is hidden from users but is still there to ensure the correctness of the specifications. Guidance is continuously offered through dialogue, which is influenced by but does not directly follow the steps of construction of the specification.The natural language constraints we use in this thesis are theories of dialogue coherence, called "focus" theories. They define what can be spoken about next in a dialogue based on what has already been discussed and the subject under discussion. The theories take into account what participants in a dialogue pay attention to and try to ensure that the rest of the dialogue is related to it. The systems tries to help its users define how a research group WWW site should look like. The way the dialogue evolves from discussing the research group, to discussing the site and its associated home page, to discussing the set of publication can quite easily be followed. The use of pronouns helps in making the text fell natural. It would have been difficult to achieve the same result without using focus rules.Other techniques for organising dialogues, such as those based on the intentions under¬ lying the dialogue (Cohen et al. 1990), would require the dialogue manager to know what the elicitation system is trying to achieve and what its plan is. For some elicitation systems, this knowledge may not be available. Similarly, techniques based on the content of the communications exchanged and how they relate, e.g., based on RST (Mann and Thompson 1987), usually require a lot of domain knowledge. They are therefore time-consumming to code. Focus theories require less information from the elicitation module while enabling the dialogue manager to structure the dialogue. However, in some cases, focus theories are not sufficient to organise a dialogue. We use a theory based on speech act (see section 3.4.1) and some ideas from Grice's work on conversation (see section 5.2.1) to deal with these cases. More generally, although we tried to minimise the impact of other theories to study in detail focus theories, it would be interesting to know whether and how we can integrate them with the work presented in this thesis. In particular, the notion of dialog act and its application to dialog grammar could be of interest. General frameworks developped to study various aspects of dialogue, including dialog acts and focus, have started to appear but work is still at an early stage (C-Star Consortium 1998; Allen and Core 1997).Organising a dialogue based on attention requires a lot of domain knowledge in order to know how things mentioned in the dialogue relate to each other. Therefore, the amount of knowledge engineering needed to build natural language applications is also an important issue. We have tried to limit the engineering difficulties by clearly separating the domain knowledge needed by our dialogue manager from its management capabilities, and by provid¬ ing a way of re-using the existing domain knowledge as far as possible. This is done by using rules which enable us to re-use part of the domain knowledge already used by the elicitation module.The contribution of this thesis is therefore the formalisation and evaluation of focus theories for requirements elicitation dialogues in natural language. The main questions we deal with are the following: • Which focus theories should we use? • What are the relations between the constraints imposed by the focus theories and the constraints inherent to the requirements elicitation process? • Does this approach improve the perceived quality of the dialogue between the elicita¬ tion tool and its users?A prototype system has been developed. This system mainly operates in the WWW site design domain. It has also been applied in other domains as an initial demonstration of the range of problems that can be tackled by our approach

Intelligent maintenance management in a reconfigurable manufacturing environment using multi-agent systems

Thesis (M. Tech.) -- Central University of Technology, Free State, 2010Traditional corrective maintenance is both costly and ineffective. In some situations it is more cost effective to replace a device than to maintain it; however it is far more likely that the cost of the device far outweighs the cost of performing routine maintenance. These device related costs coupled with the profit loss due to reduced production levels, makes this reactive maintenance approach unacceptably inefficient in many situations. Blind predictive maintenance without considering the actual physical state of the hardware is an improvement, but is still far from ideal. Simply maintaining devices on a schedule without taking into account the operational hours and workload can be a costly mistake. The inefficiencies associated with these approaches have contributed to the development of proactive maintenance strategies. These approaches take the device health state into account. For this reason, proactive maintenance strategies are inherently more efficient compared to the aforementioned traditional approaches. Predicting the health degradation of devices allows for easier anticipation of the required maintenance resources and costs. Maintenance can also be scheduled to accommodate production needs. This work represents the design and simulation of an intelligent maintenance management system that incorporates device health prognosis with maintenance schedule generation. The simulation scenario provided prognostic data to be used to schedule devices for maintenance. A production rule engine was provided with a feasible starting schedule. This schedule was then improved and the process was determined by adhering to a set of criteria. Benchmarks were conducted to show the benefit of optimising the starting schedule and the results were presented as proof. Improving on existing maintenance approaches will result in several benefits for an organisation. Eliminating the need to address unexpected failures or perform maintenance prematurely will ensure that the relevant resources are available when they are required. This will in turn reduce the expenditure related to wasted maintenance resources without compromising the health of devices or systems in the organisation

An Application of Con-Resistant Trust to Improve the Reliability of Special Protection Systems within the Smart Grid

This thesis explores an application of a con-resistant trust mechanism to improve the performance of communications-based special protection systems to further enhance their effectiveness and resiliency. New initiatives in the energy sector are paving the way for the emergent communications-based smart grid technology. Smart grids incorporate modern technologies in an effort to be more reliable and efficient. However, with the benefits of this new technology comes added risk. This research utilizes a con-resistant trust mechanism as a method to quickly identify malicious or malfunctioning protection system nodes in order to mitigate the resulting instabilities in the smart grid. The feasibility and performance of this trust architecture is demonstrated through experiments comparing a simulated special protection system implemented with a con-resistant trust mechanism and without via an analysis of variance statistical model. The simulations yield positive results when implementing the con-resistant trust mechanism within the communications-based special protection system for the smart grid