Towards a theoretical foundation of IT governance: the COBIT 5 case

Abstract: COBIT, (Control Objectives for Information and Information related Technologies) as an IT governance framework is well-known in IS practitioners communities. It would impair the virtues of COBIT to present it only as an IT governance framework. COBIT analyses the complete IS function and offers descriptive and normative support to manage, govern and audit IT in organizations. Although the framework is well accepted in a broad range of IS communities, it is created by practitioners and therefore it holds only a minor amount of theoretical supported claims. Thus critic rises from the academic community. This work contains research focusing on the theoretical fundamentals of the ISACA framework, COBIT 5 released in 2012. We implemented a reverse engineering work and tried to elucidate as much as possible propositions from COBIT 5 as an empiricism. We followed a qualitative research method to develop inductively derived theoretical statements. However our approach differs from the original work on grounded theory by Glaser and Strauss (1967) since we started from a general idea where to begin and we made conceptual descriptions of the empirical statements. So our data was only restructured to reveal theoretical findings. We looked at three candidate theories: 1) Stakeholder Theory (SHT), 2) Principal Agent Theory (PAT), and 3) Technology Acceptance Model (TAM). These three theories are categorized and from each theory, several testable propositions were deduced. We considered the five COBIT 5 principles, five processes (APO13, BAI06, DSS05, MEA03 and EDM03) mainly situated in the area of IS security and four IT-related goals (IT01, IT07, IT10 and IT16). The choice of the processes and IT-related goals are based on an experienced knowledge of COBIT as well of the theories. We constructed a mapping table to find matching patterns. The mapping was done separately by several individuals to increase the internal validity. Our findings indicate that COBIT 5 holds theoretical supported claims. The lower theory types such as PAT and SHT contribute the most. The presence and contribution of a theory is significantly constituted by IT-related goals as compared to the processes. We also make some suggestions for further research. First of all, the work has to be extended to all COBIT 5 processes and IT-related goals. This effort is currently going on. Next we ponder the question what other theories could be considered as candidates for this theoretical reverse engineering labour? During our work we listed already some theories with good potential. Our used pattern matching process can also be refined by bringing in other assessment models. Finally an alternative and more theoretic framework could be designed by using design science research methods and starting with the most relevant IS theories. That could lead to a new IT artefact that eventually could be reconciled with COBIT 5

A new hybrid implicit-explicit FDTD method for local subgridding in multiscale 2-D TE scattering problems

The conventional finite-difference time-domain (FDTD) method with staggered Yee scheme does not easily allow including thin material layers, especially so if these layers are highly conductive. This paper proposes a novel subgridding technique for 2-D problems, based on a hybrid implicit-explicit scheme, which efficiently copes with this problem. In the subgrid, the new method collocates field components such that the thin layer boundaries are defined unambiguously. Moreover, aspect ratios of more than a million do not impair the stability of the method and allow for very accurate predictions of the skin effect. The new method retains the Courant limit of the coarse Yee grid and is easily incorporated into existing FDTD codes. A number of illustrative examples, including scattering by a metal grating, demonstrate the accuracy and stability of the new method

Birefringent dispersive FDTD subgridding scheme

A novel 2D finite difference time domain (FDTD) subgridding method is proposed, only subject to the Courant limit of the coarse grid. By making mu or epsilon inside the subgrid dispersive, unconditional stability is induced at the cost of a sparse, implicit set of update equations. By only adding dispersion along preferential directions, it is possible to dramatically reduce the rank of the matrix equation that needs to be solved

The effect of job similarity on forgetting in multi-task production

For many decades, research has been done on the effect of learning and forgetting for manual assembly operations. Due to the evolution towards mass customization, cycle time prediction becomes more and more complex. The frequent change of tasks for an operator results in a rapid alternation between learning and forgetting periods, since the production of one model is causing a forgetting phase for another model. a new mathematical model for learning and forgetting is proposed to predict the future cycle time of an operator depending on the product mix of his actual assembly schedule. A main factor for this model is the job similarity between the task that is being learned and is being forgotten. In our experimental study the impact of job similarity onto the forgetting effect is measured. Two groups of operators were submitted to an equal time schedule, with other tasks to perform. At first, both groups were asked to perform the same main task. In the subsequent phase, they were submitted to different assembly tasks, each with another job similarity towards the main task, before again executing that main task. After a period of inactivity, the main task was assembled again by every subject. Results confirm that a higher job similarity results in a lower forgetting effect for the main task

Provably stable local application of crank-Nicolson time integration to the FDTD method with nonuniform gridding and subgridding

This contribution removes some doubts about the stability issues associated with the local and anisotropic use of Crank-Nicolson (CN) time integration in Finite-Difference Time-Domain (FDTD) simulations with spatial irregularities such as nonuniformity and subgridding

Provably stable local application of crank-Nicolson time integration to the FDTD method with nonuniform gridding and subgridding

This contribution removes some doubts about the stability issues associated with the local and anisotropic use of Crank-Nicolson (CN) time integration in Finite-Difference Time-Domain (FDTD) simulations with spatial irregularities such as nonuniformity and subgridding. Due to the lack of space, only the most significant steps in the stability analysis are treated here. Intermediate steps as well as numerical examples and implementation details will be provided during the presentation

A Leapfrog alternating-direction hybrid implicit-explicit FDTD method

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An in-depth stability analysis of nonuniform FDTD combined with novel local implicitization techniques

This work focuses on efficient full-wave solutions of multiscale electromagnetic problems in the time domain. Three local implicitization techniques are proposed and carefully analyzed in order to relax the traditional time step limit of the Finite-Difference Time-Domain (FDTD) method on a nonuniform, staggered, tensor product grid: Newmark, Crank-Nicolson (CN) and Alternating-Direction-Implicit (ADI) implicitization. All of them are applied in preferable directions, alike Hybrid Implicit-Explicit (HIE) methods, as to limit the rank of the sparse linear systems. Both exponential and linear stability are rigorously investigated for arbitrary grid spacings and arbitrary inhomogeneous, possibly lossy, isotropic media. Numerical examples confirm the conservation of energy inside a cavity for a million iterations if the time step is chosen below the proposed, relaxed limit. Apart from the theoretical contributions, new accomplishments such as the development of the leapfrog Alternating-Direction-Hybrid-Implicit-Explicit (ADHIE) FDTD method and a less stringent Courant-like time step limit for the conventional, fully explicit FDTD method on a nonuniform grid, have immediate practical applications. (C) 2017 Elsevier Inc. All rights reserved

Entire domain basis function expansion of the differential surface admittance for efficient broadband characterization of lossy interconnects

This article presents a full-wave method to characterize lossy conductors in an interconnect setting. To this end, a novel and accurate differential surface admittance operator for cuboids based on entire domain basis functions is formulated. By combining this new operator with the augmented electric field integral equation, a comprehensive broadband characterization is obtained. Compared with the state of the art in differential surface admittance operator modeling, we prove the accuracy and improved speed of the novel formulation. Additional examples support these conclusions by comparing the results with commerical software tools and with measurements