Cost accounting for shared IT infrastructures

IT infrastructure, such as servers and networking equipment, accounts for a large proportion of the IT costs in modern organizations. Typically, this IT infrastructure is shared among multiple applications and customers. Cost allocation of shared IT infrastructure is difficult and regularly based on biased cost allocation keys, which often causes free-rider problems. Measuring usage is technically difficult and incurs high costs. In this paper we propose a method to derive adequate estimators for the resource consumption of a customer-oriented service. These so-called resource profiles can then provide a basis for cost allocation keys. The estimators are derived from a series of load tests, as they are typically done before an application is launched in larger organizations. Such profiles need to be unbiased and precise even in cases of varying workloads and in rather heterogeneous environments. We describe the results of a set of experiments in an infrastructure provided by the BMW Group, and illustrate how the estimation can be integrated into existing IT service management processes. In our experiments we use Queuing Networks to validate the estimated resource profiles under different workloads.     

RiskM: A multi-perspective modeling method for IT risk assessment

Stakeholder involvement and participation are widely recognized as being key success factors for IT risk assessment. A particular challenge facing current IT risk assessment methods is to provide accessible abstractions on matters of IT risk that attend to both managerial and technical perspectives of the stakeholders involved. In this paper, we investigate whether a conceptual modeling method can address essential requirements in the IT risk assessment domain, and which structural and procedural features such a method entails. The research follows a design research process in which we describe a research artifact, and evaluate it to assess whether it meets the intended goals. In the paper, we specify requirements and assumptions underlying the method construction, discuss the structural specification of the method and its design rationale, present a prototypical application scenario, and provide an initial method evaluation. The results indicate that multi-perspective modeling methods satisfy requirements specific to the IT risk assessment domain, and that such methods, in fact, provide abstractions on matters of IT risk accessible to both a technical and a managerial audience.     

Model-based and qualitative reasoning: An introduction

Knowledge-based systems which use an explicit model of the subject they reason about are an important area in current research on Artificial Intelligence (AI). This paper surveys some of the important techniques that have been applied to qualitatively model physical systems and explains principles of model-based reasoning in diagnostic systems. (Date of reference: 1993.) This revised version was published online in June 2006 with corrections to the Cover Date.     

A probabilistic decision-making approach for the sustainable assessment of infrastructures

Sustainable development is a multidimensional concept that usually implies a simultaneous concretization of contradictory aspects. Multi-criteria decision approaches are often used for the management of conflicting perspectives. In life cycle approaches, uncertainties are unavoidable and a decision making approach dealing with life-cycle based criteria cannot disregard the uncertainties associated with the evaluation of criteria. It is the purpose of this paper to introduce a decision-making approach, based on PROMETHEE and AHP, to address both of these important issues. Moreover, the proposed approach aims to address two other types of uncertainties, inherent to the use of PROMETHEE and AHP, which arise from the selection of the generalized criterion functions and the selection of preference values, respectively. The proposed approach enhances the robustness of the decision-making approach and enables decisions to be made on a more reliable base. The approach is applied to a case study: the comparative assessment of alternatives bridges taking into account environmental, economical and social criteria evaluated over the complete life-cycle of the bridges.     

An architecture framework for enterprise IT service availability analysis

This paper presents an integrated enterprise architecture framework for qualitative and quantitative modeling and assessment of enterprise IT service availability. While most previous work has either focused on formal availability methods such as fault trees or qualitative methods such as maturity models, this framework offers a combination. First, a modeling and assessment framework is described. In addition to metamodel classes, relationships and attributes suitable for availability modeling, the framework also features a formal computational model written in a probabilistic version of the object constraint language. The model is based on 14 systemic factors impacting service availability and also accounts for the structural features of the service architecture. Second, the framework is empirically tested in nine enterprise information system case studies. Based on an initial availability baseline and the annual evolution of the 14 factors of the model, annual availability predictions are made and compared with the actual outcomes as reported in SLA reports and system logs. The practical usefulness of the method is discussed based on the outcomes of a workshop conducted with the participating enterprises, and some directions for future research are offered.     

Loginson: a transform and load system for very large-scale log analysis in large IT infrastructures

Nowadays, most systems and applications produce log records that are useful for security and monitoring purposes such as debugging programming errors, checking system status, and detecting configuration problems or even attacks. To this end, a log repository becomes necessary whereby logs can be accessed and visualized in a timely manner. This paper presents Loginson, a high-performance log centralization system for large-scale log collection and processing in large IT infrastructures. Besides log collection, Loginson provides high-level analytics through a visual interface for the purpose of troubleshooting critical incidents. We note that Loginson outperforms all of the other log centralization solutions by taking full advantage of the vertical scalability, and therefore decreasing Capital Expenditure (CAPEX) and Operating Expense (OPEX) costs for deployment scenarios with a huge volume of log data.     

The assessment of IT capability

Abstract  The 1988 Educational Reform Act established in England and Wales a National Curriculum which sets out in statute assessment objectives and teaching programmes for a range of subjects. IT plays an important part in this Curriculum, and is intended to permeate it in a natural way. Since IT has its own objectives-relating to what is termed IT capability-this raises particular problems of cross-curricular, context-led assessment, which this paper explores. In doing so, the paper sets up a model of pupil progression for IT capability development, which provides a theoretical basis to the practical problems of assessment.     

Attention-shaping tools,expertise, and perceived control in IT project risk assessment

This study investigates the use of attention-shaping tools and their interactions with expertise and perceptions of control on individual decision-making about risks in IT projects. The paper uses data collected from 118 IT project experts and 140 novices through a role-playing experiment to provide several novel insights into how these three factors independently and collectively influence perception of risks and subsequent project continuation decisions. First, attention-shaping tools have a significant effect on both risk perception and decision-making. However, among individuals with low expertise, risk shaping tools exhibit a significant but dual-sided effect on risk perception. They help identify risks captured by the attention-shaping tool but simultaneously introduce blind spots in their risk awareness. Second, while individuals with greater expertise perceive significantly higher levels of risks relative to those with lower expertise, the level of expertise had generally no influence on decision-making. Third, we found that perceived control is a powerful factor influencing both risk perception and decision-making. Implications for research and practice are discussed along with potential avenues for future research.     

Towards Model-based Methods for Developing Model-based Systems

Model-based reasoning (MBR) is a means of reasoning about models of all kinds, as appropriate to the task at hand. This includes adaptation of models in response to changes in a problem-solving context or task goals. Thus, MBR exemplifies the characteristics of a smart adaptive system. Constructing appropriate models and matching them to the best inference engines requires a means of describing or defining models. This can be achieved by means of a set of generic model properties. As well as defining models one may decompose the problem domain into a number of tasks to be performed. It then becomes possible to design appropriate models for the domain by mapping these tasks to the model properties. This mapping can be instantiated procedurally, however more generality will result if a model-based approach is taken. As a step towards that goal quality function deployment is investigated as a suitable design method.     

An integrated modelling approach for the assessment of land use change effects on wastewater infrastructures

The simulation of sewage systems and wastewater treatment plants is strategic for assessing the effect of new dwellings on the existing water facilities. This paper introduces an integrated framework made by a land use change model, a sewage system simulator, and a wastewater treatment plant simulator. This is a complex system since each element is characterized by different dynamics. The land use change model simulates the annual expansion of an urban area according to planners’ guidelines; the sewage system simulator investigates the response of the drainage system to the expansion. The wastewater treatment plant is simulated in order to assess the impact of the new outflows on the existing plant. The three models are integrated into a Simulink model. Two components of the developed framework are based on models well established in literature. The proposed framework is tested on a simple case study of a small town located in south west of Scotland.     

Designing infrastructures for creative engagement

Abstract

As museums extend their scope beyond traditional exhibition spaces and into everyday practices and institutions, it is necessary to develop suitable conceptualisations of how technology can be understood and designed. To this end, I propose the concept of infrastructures, as both social and material, as a useful frame for discussing important challenges and opportunities in terms of designing for audience engagement. I further argue that when designing infrastructures, an important challenge is to develop the social aspects of infrastructures in terms of creating, maintaining and developing relationships between organisations and communities. I argue that this is as much an object of design as technical interactive systems and discuss the relational work undertaken in this activity. The ideas of infrastructure and relational work is illustrated through a case describing the design of a system for cultural heritage engagement for Danevirke museum covering issues relating to the Danish minority in northern Germany.     

Safety-based availability assessment at design stage

The availability of a system or equipment is one of the crucial characteristics that measures the customer satisfaction and strongly influences his final choice decision between concurrent products. The aim of this work is to provide an approach to improve the products availability assessment by taking into account the safety criteria by considering the use situations at design stage. Our work focuses on the routine design of complex products. The availability is often simply estimated considering reliability and maintainability. Basically, the intrinsic availability is the probability that it is operating satisfactorily at any point in time when used under conditions stated by design specifications. The time considered includes operating time and active repair time. Thus, intrinsic availability excludes from consideration all other times in the product lifecycle such as: accident management time, storage time, administrative time or logistic time. But many studies show that the loss of availability performance is also due to accidents that occur in different unforeseeable utilization situations. This engenders stops of the system to ensure the users safety according to standards recommendations. In this purpose, we consider the structural product architecture and the different use cases that correspond to the operational states and downtimes due to stop events that may happen during the utilization like failures, maintenance tasks and accidents. Then, we propose a product behavioral analysis including the use cases to describe interactions between the product and users or maintenance operators. We use Markov chains to model the use cases corresponding to operating time (OT), maintenance time (MT) and preparing time after accidents (RT). Then these three parameters are considered to specify a generic approach to improve the availability assessment. Such an approach provides the traceability of the product behavior along its lifecycle. In this way, the main causes of stop can be identified and this may guide the designer for improving the availability of the product future versions. To validate our approach, an application is presented considering a printing line. The comparison of our simulation considering an industrial case study shows a good agreement about the influence of safety on the availability.     

A method for the evaluation of risk in IT projects

Information technology projects are particularly prone to failure due to their specific characteristics, making risk management become one of the critical elements in IT projects management. That is why several authors have developed risk evaluation methods, some of them based on fuzzy logic. This article proposes a new risk assessment method based in a combination of fuzzy analytic hierarchy process (FAHP) and fuzzy inference system (FIS). FIS is used for the integration of the groups of risk factors. These risk factors are the evaluation criteria of a modified FAHP which minimizes the disadvantages of the classic implementation of FAHP in order to obtain a more intuitive and easily adjustable model for multicriteria decision analysis with a lower computational need. The proposed model takes into consideration the different levels of uncertainty, the interrelationship among groups of risk factors, and the possibility of adding or suppressing options without losing the consistency with previous evaluations. The new method is especially suitable for the evaluation of development projects in the area of IT in which multiple interrelated risk factors can be particularly uncertain and imprecise. To implement the evaluation method, a hierarchy of risk factors was implemented. A numerical example is presented with data from three actual cases of IT projects, showing the applicability of the new method, the suitability of the selected taxonomy, and the significance of a few risk factors. Several future lines of work are proposed.     

Dynamic quorums for DHT-based enterprise infrastructures

Peer-to-peer systems (P2P) have become a popular technique to design large-scale distributed applications in unmanaged inter-domain settings, such as file sharing or chat systems, thanks to their capabilities to self-organize and evenly split the load among peers. Recently, enterprises owning a large IT hardware and software infrastructure started looking at these P2P technologies as a means both to reduce costs and to help their technical divisions to manage huge number of devices characterized by a high level of cooperation and a relatively low churn. Gaining a quick exclusive access to the system for maintenance or auditing purposes in these enterprise infrastructures is a fundamental operation to be implemented. Conversely, this kind of operation is usually not an issue in the previously mentioned inter-domain setting, where peers are inherently independent and cannot be managed.     

Improving IT effectiveness through software process assessment

This paper provides some answers to the frequently asked question: what proof is there that process management gives measurable benefit in practice? We report the results of an improvement programme that is helping to improve the effectiveness of Scotland's IT community. This programme is currently operating in over 20 organizations and uses software process assessment as a key element. The majority of organizations have been on the programme for over a year and we have found that benefits can be obtained as early as six months from the outset of an assessment-based improvement programme. Using the experience of working with these organizations, we discuss how to set up an improvement programme and define the roles, responsibilities and critical factors that we have found successful.     

Model-based testing for real

Model-based testing relies on abstract behavior models for test case generation. These models are abstractions, i.e., simplifications. For deterministic reactive systems, test cases are sequences of input and expected output. To bridge the different levels of abstraction, input must be concretized before being applied to the system under test. The systems output must then be abstracted before being compared to the output of the model.The concepts are discussed along the lines of a feasibility study, an inhouse smart card case study. We describe the modeling concepts of the CASE tool AutoFocus and an approach to model-based test case generation that is based on symbolic execution with Constraint Logic Programming.Different search strategies and algorithms for test case generation are discussed. Besides validating the model itself, generated test cases were used to verify the actual hardware with respect to these traces.     

Using IT to assess IT: Towards greater authenticity in summative performance assessment

An applied Information Technology (IT) course that is assessed using pen and paper may sound incongruous but it is symptomatic of the state of high-stakes assessment in jurisdictions such as Western Australia. Whereas technology has permeated most aspects of modern life, including schooling, and more has been demanded of education systems in terms of outcomes and participation, methods of summative assessment have changed little and are seriously out of alignment with curriculum, pedagogy and the needs of individuals and society.