Evaluating cost taxonomies for information systems management

The consideration of costs, benefits and risks underpin many Information System (IS) evaluation decisions. Yet, vendors and project-champions alike tend to identify and focus much of their effort on the benefits achievable from the adoption of new technology, as it is often not in the interest of key stakeholders to spend too much time considering the wider cost and risk implications of enterprise-wide technology adoptions. In identifying a void in the literature, the authors of the paper present a critical analysis of IS-cost taxonomies. In doing so, the authors establish that such cost taxonomies tend to be esoteric and difficult to operationalize, as they lack specifics in detail. Therefore, in developing a deeper understanding of IS-related costs, the authors position the need to identify, control and reduce IS-related costs within the information systems evaluation domain, through culminating and then synthesizing the literature into a frame of reference that supports the evaluation of information systems through a deeper understanding of IS-cost taxonomies. The paper then concludes by emphasizing that the total costs associated with IS-adoption can only be determined after having considered the multi-faceted dimensions of information system investments.     

Investment evaluation within project management: an information systems perspective

This paper is seeking to make a contribution through exploring project managementfrom the perspective of information systems (IS) investment evaluation.Organizational investments in IS are significant in financial terms and, as aresult, management would appear set to increasingly scrutinize such expenditurethrough tighter forms of decision-making and corporate governance. Inturn, this has increased the motivation of project managers toappropriately evaluate the impact of their IS before,during and after the investments are signed off. Thisperspective is not restricted to any one industry sector, with the authorseeking motivation for a better understanding of investment evaluation within aproject management context. This paper sets out to explain why andhow investment evaluation should be embedded in project managementin order to support an increase in the effectiveness of project management,thereby increasing the prospects of project success. While doing so,the reader will be provided with several touch-points that serve to outline thepurpose and challenges facing those seeking to evaluate their investments. Theauthor starts off with a contextualization of project management and its phasedactivities, such that a clear understanding of the contribution that investmentevaluation plays within robust project management can be demonstrated. Then, theperspective of investment versus consumption is presented, groundedwithin the strategic grid, which classifies information technology-basedprojects as either: strategic, turnaround, factory or support. The author thenpresents evaluation as a life-cycle process, where evaluation is classified intofour distinctive phases, namely ex-ante evaluation, metrics,command and control and ex-post evaluation, in doing so,emphasizing that evaluation needs to be seen as a process that runs through thelife cycle of a project rather than as a hurdle that needs to be cleared toensure financial approval.     

Basket problems in margin calculation: Modelling and algorithms

This paper considers combinatorial models and algorithms for the problems of constructing a basket of stock positions representing a capitalization-weighted market index for the purpose to be offset in the margin calculation by a position in other index products as index options, futures or participation units. We show how following the regulatory definition of the basket a 0–1 programming model of knapsack type can be obtained and how to develop the related efficient exact or approximation grab-the-basket algorithms. All approximations are supplied by the performance guarantee evaluations.     

Modelling alcohol problems: total recovery

Binge drinking in the UK is an increasing problem, resulting in negative health, social and economic effects. Mathematical modelling allows for future predictions to be made and may provide valuable information regarding how to approach solving the problem of binge drinking in the UK. We develop a 3-equation model for alcohol problems, specifically binge drinking, which allows for total recovery. Individuals are split into those that are susceptible to developing an alcohol problem, those with an alcohol problem and those in treatment. We find that the model has two equilibrium points: one without alcohol problems and one where alcohol problems are endemic in the population. We compare our results with those of an existing model that does not allow for total recovery. We show that without total recovery, the threshold for alcohol problems to become endemic in the population is lowered. The endemic equilibrium solution is also affected, with an increased proportion of the population in the treatment class and a decreased proportion in the susceptible class. Including totally recovery does not determine whether the proportion of individuals with alcohol problems increases or decreases, however it does effect the size of the change. Parameter estimates are made from information regarding binge drinking where we find an increase in the recovery rate decreases the proportion of binge drinkers in the population.     

Computation of local radius of information in SM-IBC identification of nonlinear systems

System identification consists in finding a model of an unknown system starting from a finite set of noise-corrupted data. A fundamental problem in this context is to asses the accuracy of the identified model. In this paper, the problem is investigated for the case of nonlinear systems within the Set Membership—Information Based Complexity framework of [M. Milanese, C. Novara, Set membership identification of nonlinear systems, Automatica 40(6) (2004) 957–975]. In that paper, a (locally) optimal algorithm has been derived, giving (locally) optimal models in nonlinear regression form. The corresponding (local) radius of information, providing the worst-case identification error, can be consequently used to measure the quality of the identified model. In the present paper, two algorithms are proposed for the computation of the local radius of information: The first provides the exact value but requires a computational complexity exponential in the dimension of the regressor space. The second is approximate but involves a polynomial (quadratic) complexity.     

How to give away £100 million: information for senior decision makers

Every year the National Coal Board divides about £100 million capital for purchasing mining machinery between 12 mining regions. This paper discusses how the allocation should be made, and in particular what information should be provided to the senior management staff who take the final decision.     

Modelling of topological derivatives for contact problems

The problem of topology optimization is considered for free boundary problems of thin obstacle types. The formulae for the first term of asymptotics for energy functionals are derived. The precision of obtained terms is verified numerically. The topological differentiability of solutions to variational inequalities is established. In particular, the so-called outer asymptotic expansion for solutions of contact problems in elasticity with respect to singular perturbation of geometrical domain depending on small parameter are derived by an application of nonsmooth analysis. Such results lead to the topological derivatives of shape functionals for contact problems. The topological derivatives are used in numerical methods of simultaneous shape and topology optimization. Partially supported by the grant 4 T11A 01524 of the State Committee for the Scientific Research of the Republic of Poland     

Index information algorithm with local tuning for solving multidimensional global optimization problems with multiextremal constraints

 Multidimensional optimization problems where the objective function and the constraints are multiextremal non-differentiable Lipschitz functions (with unknown Lipschitz constants) and the feasible region is a finite collection of robust nonconvex subregions are considered. Both the objective function and the constraints may be partially defined. To solve such problems an algorithm is proposed, that uses Peano space-filling curves and the index scheme to reduce the original problem to a H?lder one-dimensional one. Local tuning on the behaviour of the objective function and constraints is used during the work of the global optimization procedure in order to accelerate the search. The method neither uses penalty coefficients nor additional variables. Convergence conditions are established. Numerical experiments confirm the good performance of the technique. Received: April 2002 / Accepted: December 2002 Published online: March 21, 2003 RID="⋆" ID="⋆" This research was supported by the following grants: FIRB RBNE01WBBB, FIRB RBAU01JYPN, and RFBR 01–01–00587. Key Words. global optimization – multiextremal constraints – local tuning – index approach     

Cyclic solutions in dynamical systems generated by local variational problems with objective-function singularities

The article considers cyclic systems generated by local variational problems with various singularities in the objective function. Conditions for the creation of cyclic solutions are examined. Translated from Nelineinaya Dinamika i Upravlenie, pp. 7–14, 1999.     

Adaptive mesh selection asymptotically guarantees a prescribed local error for systems of initial value problems

We study potential advantages of adaptive mesh point selection for the solution of systems of initial value problems. For an optimal order discretization method, we propose an algorithm for successive selection of the mesh points, which only requires evaluations of the right-hand side function. The selection (asymptotically) guarantees that the maximum local error of the method does not exceed a prescribed level. The usage of the algorithm is not restricted to the chosen method; it can also be applied with any method from a general class. We provide a rigorous analysis of the cost of the proposed algorithm. It is shown that the cost is almost minimal, up to absolute constants, among all mesh selection algorithms. For illustration, we specify the advantage of the adaptive mesh over the uniform one. Efficiency of the adaptive algorithm results from automatic adjustment of the successive mesh points to the local behavior of the solution. Some numerical results illustrating theoretical findings are reported.     

Modelling impacts of cropping systems: Demands and solutions for DEX methodology

Decision modelling of diverse groups of problems makes different requirements to the modelling methodologies and software. We present an actual decision problem and the required characteristics of corresponding decision models. The problem is from agronomy and addresses the ecological and economic impacts of cropping systems, with the focus on the differences between cropping systems with conventional crops and the ones with genetically modified crops. We describe the extensions of an existing DEX qualitative multi-attribute modelling methodology, which were made to cope with the challenges of the problem. The extensions address general hierarchical structures, probabilistic utility functions and numerical values of basic attributes. A new, freely available software tool called proDEX was implemented to support the extended methodology. In this paper we describe the problem of cropping system assessment, propose methodological extensions to DEX, and present the implementation of proDEX.     

Modelling preventive maintenance for deteriorating repairable systems

This paper is concerned with practical methods for the analysisand modelling of data for repairable systems which are subjectto preventive maintenance (PM) and still have an increasingrate of occurrence of failures. Aspects of testing for trendand fitting a nonhomogeneous Poission process to data are discussedModels for scheduling preventive maintenance to minimize costor maximize availability are proposed. They show that the optimalPM cycle interval for these systems decreases with increasingequipment age. One-cycle and two-cycle finite-time-zone replacementmodels are also developed to decide the optimal time for replacingthe equipment in current use.     

Modelling framework for artificial hybrid dynamical systems

Many current industry branches use hybrid approaches to solve complex application problems. Over the last decades, different tools for the simulation of such hybrid systems (e.g. Hysdel and YAMLIP) as well as the identification of hybrid systems (e.g. HIT, MLP and OAF NN) have been developed. The framework presented in this work facilitates the integration of artificial feed-forward neural networks in the modelling process of hybrid dynamical systems (HDS). Additionally, the framework provides a structured language for characterising these feed-forward networks itself. Therefore, an interdisciplinary exchange in the field of neural networks and its integration into hybrid dynamical systems is enabled. Focusing on hybrid systems with autonomous events, two different approaches, namely the artificial hybrid model and the artificial hybrid dynamics, are introduced. Challenges of the modelling process of HDS are reflected and advantages as well as disadvantages are discussed. The case study includes two common examples of HDS and analyses the simulation results and examines limitations of the modelling framework.     

Hybrid systems: Modelling and analysis using emergent dynamics

In this paper, we discuss modelling and analysis of hybrid systems with physical interaction dynamics. Such systems are typically considered complex and they are modelled using abstractions. Abstractions may, however, unintentionally exclude critical details, leading to partial or false results. Therefore, we study here use of a particle system in modelling and analysis. The novelty of the particle system is that it is designed to reveal interaction dynamics as emergent dynamics; thus, supporting analysis of complex and intricate interaction dynamics with acceptable modelling effort. As the main contribution, we formalize the particle system, and use it to model and analyze hybrid systems, both mechanical and biological, with nontrivial interaction dynamics.     

On structuring problems of job design met in the development and maintenance of information systems

In the development and maintenance of information systems data processing tasks are assigned either to a computer or to a man. In this paper we consider five decisions made during the development phase. These decisions have an influence on the contents of jobs: 1. distribution of work between man and computer, 2. construction of man-computer interface, 3. grouping tasks into jobs, 4. design of control part of new information system, 5. assignment of people to jobs.During the use of an information system both the person and his job will change. Here various combinations of changes in a person-job pair are classified and analyzed.This research has been supported by the Academy of Finland.     

Extremal problems for triple systems

In this article Turán-type problems for several triple systems arising from (k, k ? 2)-configurations [i.e. (k ? 2) triples on k vertices] are considered. It will be shown that every Steiner triple system contains a (k, k ? 2)-configuration for some k < c log n/ log log n. Moreover, the Turán numbers of (k, k ? 2)-trees are determined asymptotically to be ((k ? 3)/3).(ⁿ₂) (1?o(1)). Finally, anti-Pasch hypergraphs avoiding (5, 3) -and (6, 4)-Configurations are considered. © 1993 John Wiley & Sons, Inc.     

Existence of local minima for capillarity problems

In this paper we study problems in capillarity theory associated with energy functionals for which no lower bounds exist. We treat the cases of pendent and rotating liquid drops. In order to show the existence of local minima we prove suitablea priori estimates for their diameter. To obtain these results sufficient conditions on the included volume depending respectively on the centrifugal and gravitational potential must be satisfied.