bluuebunny/crossref_metadata_2025 huggingface dataset:
Sliding mode control of a permanent magnet direct drive under non‐linear friction
Authors: Brock Stefan
Published: June 2011

Purpose

The purpose of this paper is to find a simple structure of motion controller for permanent magnet direct drive. Application of sliding mode controller theory and equivalent disturbance estimator creates proper non‐linear characteristics, which ensures controller robustness against friction.

Design/methodology/approach

The position and speed controller is based on robust design methodology introduced by a sliding mode technique. The paper proposes a combination of sliding mode controller and proportional integral (PI) equivalent disturbance estimator. The friction model is Coulomb friction with a large static friction effect. The double boundary layer is used to compensate the effect of stiction. The synthesis is performed using simulation techniques and subsequently the behaviour of a laboratory speed control system is validated in the experimental setup. The control algorithms of the system are performed by a microprocessor floating point DSP control system.

Findings

The proposed sliding mode controller structure with equivalent disturbance estimator guarantees expected robustness against friction. Experimental results show that the control approach can decrease the tracking error, enhance the system's robustness and attenuate high‐frequency chattering in the control signal.

Research limitations/implications

The proposed controller was tested on a single machine under well‐defined conditions. Further investigations are required before any industrial applications.

Practical implications

The proposed controller synthesis and its results may be very helpful in robotic systems where non‐linear friction is a characteristic for many industrial robots and manipulators.

Originality/value

The method of sliding mode controller synthesis was proposed and validated by simulation and experimental investigations.
Modification of Park variable transformation for wye‐connected winding without neutral wire
Authors: Burlikowski Wojciech
Published: June 2011

Purpose

The purpose of this paper is to present a modification of the Park variable transformation for a three‐phase wye‐connected winding without neutral wire. A new physical interpretation of the winding equivalent circuit is proposed.

Design/methodology/approach

An equivalent circuit representing reluctance motor stator winding is rearranged to enable easier physical interpretation of obtained voltage equation. The Park transformation and constraints resulting from Kirchhof's laws are then applied to obtain a two‐axis mathematical model of the motor.

Findings

A new physical two‐phase interpretation of the voltage equation for a three‐phase wye‐connected winding without neutral wire is proposed. A novel two‐axis transformation is formulated for all variables. Compared to the Park transformation, which is the same for all variables, in the proposed transformation its matrices for currents and voltages/flux linkages are different, yet strongly interconnected.

Research limitations/implications

The proposed transformation is formulated for a specific type of winding connection scheme. Therefore, it is limited in its application.

Practical implications

From the practical point of view, the proposed transformation could be very useful as it applies to the most popular stator winding connection scheme. Its main advantages are fewer number of trigonometric parameters in the matrices and measurability of all currents and voltages present in its voltage equations. It could be of special importance for electric machines with non‐sinusoidal field distribution (e.g. Brushless DC).

Originality/value

The paper presents a new type of variable transformation for three‐phase electric machines with wye‐connected windings without neutral wire. Proposed transformation combines different transformations for currents and voltages/flux linkages.
Computational cost‐effective modelling of non‐linear characteristics in permanent magnet synchronous motors
Authors: Franck David , Hafner Martin , Hameyer Kay
Published: June 2011

Purpose

In the optimisation of electrical drives, the required degree of detail in the simulation increases constantly. Especially, the industrial demand on multi‐objective optimisation craves for highly efficient models. The purpose of this paper is to propose a hybrid model for the computation of the air‐gap field of a permanent magnet synchronous motor (PMSM) combining analytic and numeric methods.

Design/methodology/approach

The classic conformal mapping (CM) approach is improved by the numeric approximation of the required ansatz‐functions. This approach allows to consider the non‐linear permeability of the applied materials and complex geometries. The non‐linear permeance‐function is described by a one‐dimensional wave varying in time and space.

Findings

The permeance‐function has to be derived for different load cases at the actual stage.

Research limitations/implications

A physical motivated modelling allowing for an appropriate interpolation between different load cases is planned in further research.

Practical implications

The proposed approach is applied to a surface mounted PMSM. It is validated by means of a non‐linear finite element analysis.

Originality/value

The hybrid model offers to consider rotors with buried magnets using the CM approach. It is possible to either use analytic or numeric modelling of rotor ansatz‐function, stator current ansatz‐function and permeance‐function with the proposed approach. Non‐linear permeability of iron is modelled by means of a wave representation of the permeance‐function. This can significantly reduce the computational cost in the design and optimisation stage of electrical machines.
Interactive visualization of transient 3D electromagnetic and n‐dimensional parameter spaces in virtual reality
Authors: Hafner Martin , Böhmer Stefan , Henrotte François , Hameyer Kay
Published: June 2011

Purpose

Nowadays many parameter studies for the design and optimization of electromagnetic devices are carried out by means of 2D and 3D nonlinear finite element (FE) models. Through optimization algorithms selecting one design as optimal with respect to the chosen cost function, the user does not gain any intuitive clue of the interrelations existing between design parameters, although numerous computations have been performed across the whole parameter space of the system. The purpose of this paper is to visualize a complex nonlinear FE solution system, which is parameterized through a number of control variables, in virtual reality (VR).

Design/methodology/approach

This paper presents a visualization approach for n‐dimensional parameter spaces of FE solutions in VR and the corresponding interpolation methods for enabling navigation through it.

Findings

The solution of an arbitrary electromagnetic FE problem is categorized with respect to possible changes, due to chosen design parameters, within the solution itself and variations in the underlying mesh in order to find appropriate interpolation methods for the visualization of each type of parameter space.

Practical implications

The implementation is based on modifying the popular Visualization Toolkit (VTK).

Originality/value

The paper presents different solution approaches for the visualization of an interpolation between arbitrary different meshes, but the problem remains unsolved and requires further research.
Accounting for saturation in conformal mapping modeling of a permanent magnet synchronous machine
Authors: Hafner Martin , Franck David , Hameyer Kay
Published: June 2011

Purpose

In the electromagnetic field simulation of modern servo drives, the computation of higher time and space harmonics is essential to consider appearing torque pulsations, radial forces and ripple torques. The purpose of this paper is to propose a method to cover the effect of saturation on the armature flux density within conformal mapping (CM) by an finite element (FE) re‐parameterization.

Design/methodology/approach

Field computation by CM techniques is a time‐effective method to compute the radial and tangential field components, but it generally neglects the effect of saturation.

Findings

This paper presents a method to re‐parameterize the CM approach by single FE computations so as to consider saturation in the model over a wide operation range of the electrical drive.

Practical implications

The proposed method is applied to a surface permanent magnet synchronous machine, and compared to numerical results obtained by finite element analysis (FEA).

Originality/value

The paper shows that an accuracy similar to that of FE simulations can be obtained with still the low‐computation time that is the characteristic of analytical models.
Field‐circuit simulation of the dynamics of the outer rotor permanent magnet brushless DC motor
Authors: Knypiński Łukasz , Nowak Lech
Published: June 2011

Purpose

The purpose of this paper is to elaborate a mathematical model of dynamic operation of the permanent magnet brushless DC (BLDC) motor with outer rotor and investigate the influence of magnets width on the dynamic parameters.

Design/methodology/approach

The mathematical model of the devices includes: the equation of the electromagnetic field, the electric circuit equations and equation of mechanical motion. In elaborated algorithm, all these equations are coupled – therefore they are solved simultaneously. The numerical implementation is based on finite element method and step‐by‐step algorithm. The non‐linear‐coupled field‐circuit equations have been solved by using the Newton‐Raphson algorithm. The computer code for dynamics simulation of the machine has been developed.

Findings

The elaborated algorithm and the computer code have been applied for the 2D simulation of BLDC motor dynamics. The algorithm has a good convergence and its usefulness was proved. Various results of the analysis are presented and discussed.

Originality/value

The presented approach and computer code can be successfully applied to the design and optimization of different structure of the BLDC motors.
Computer analysis of high‐speed PM BLDC motor properties
Authors: Krykowski Krzysztof , Hetmańczyk Janusz , Gałuszkiewicz Zbigniew , Miksiewicz Roman
Published: June 2011

Purpose

The purpose of this paper is to elaborate a method of computer analysis of high‐speed motor with specific parameters and verifying the obtained results, i.e. computer models by experimental (laboratory) tests.

Design/methodology/approach

In order to determine motor properties from the viewpoint of energy conversion, a model using FEM was worked out with the help of Maxwell software. To determine static and dynamic properties of both motor and drive, Matlab/Simulink models were used; one of these models was a built‐in (library) model, the other one was proposed by the authors.

Findings

The new analysis method and model of high‐speed motor have been carried out.

Research limitations/implications

The permanent magnet brushless direct current high‐speed motor was the subject of the research. In the first part of the research, the properties of the motor were determined by using finite element method.

Practical implications

The laboratory prototype can be a starting point in establishing the production of the high‐speed motors with rotational speed in the range of 50,000‐100,000 rpm.

Social implications

At this moment, there are several possible application of the high‐speed motor and it should be expected that other new applications can appear in near future after the start of the production.

Originality/value

The paper shows that the computer‐based analysis method determines the motor properties accurately. It is also pointed out that a motor with half‐open slots has advantageous properties. The new simulation model of high‐speed motor has been carried out. This model allows taking into account some imperfections caused by slots and rectangular cross‐section magnets.
Modelling of rotational magnetization in anisotropic sheets
Authors: Mazgaj Witold
Published: June 2011

Purpose

The aim of this paper is to present a new relatively simple model of the rotational magnetization process in anisotropic sheets.

Design/methodology/approach

The surface of a sample of an anisotropic sheet is divided into an assumed number of specified directions. To each direction a certain hysteresis loop, the so‐called direction hysteresis, is assigned. The parameters of the proposed model are calculated on the basis of such values as the saturation flux density, the residual flux density (remanence), and the coercive force. It is also necessary to take into account the anisotropy constant and also the distribution function of the grains in the sample of the given anisotropic material.

Findings

The model of the rotational magnetization process of soft ferromagnetic materials takes into account two fundamental phenomena: the irreversible domain wall movements and the rotations of the flux density vectors from the easy magnetization axes. This model can also be used for the modelling of the axial magnetization process.

Practical implications

The proposed model can be used in numerical calculations of the rotational magnetization in magnetic circuits of electrical machines for any work conditions. However, for the comprehensive calculation of the magnetic field distribution this model should be completed with eddy current equations. Eddy currents influence magnetic field distribution in electric steel sheets.

Originality/value

A new model of the rotational magnetization process in anisotropic sheets is proposed.
Performance analysis of the sliding‐mode speed observer with magnetizing reactance estimation for the sensorless induction motor drive
Authors: Orlowska‐Kowalska Teresa , Dybkowski Mateusz , Tarchala Grzegorz
Published: June 2011

Purpose

The purpose of this paper is to obtain an accurate and robust estimation method of the rotor flux and speed for the sensorless induction motor (IM) drive with magnetizing reactance variations.

Design/methodology/approach

The sensorless IM drive with sliding mode flux and speed observer (SMO) is presented. Proposed estimation algorithm is extended with the additional magnetizing reactance estimator based on the magnetizing characteristic of the IM. The dynamical and steady‐state properties of the drive system in the low‐speed and in the field‐weakening regions are tested. The simulation results are verified by experimental tests, over the wide range of motor speed and drive parameter changes.

Findings

It is shown that the sensorless induction motor drive can work stable in wide speed range using the Sliding‐Mode Observer with additional magnetizing reactance estimator.

Research limitations/implications

The investigation looked mainly at the speed estimation methodology with additional motor parameter estimator.

Practical implications

The proposed SMO can be easily implemented on digital signal processors. The implementation was tested in an experimental setup with DS1103 card. The fixed‐point realisation needs to be developed to obtain the practical application in the industrial drive systems.

Originality/value

The SMO with an additional magnetizing reactance estimator based on magnetizing characteristic of the IM is tested. This method of the speed and flux reconstruction can be applied in different electrical drives working in wide speed range, including very low‐speed region and field‐weakening region, too. The proposed solution is not sensitive to magnetizing reactance variations and is simple in practical implementation in the real‐time system.
Robust control of PMSM system using the structure of MFC
Authors: Pajchrowski Tomasz
Published: June 2011

Purpose

The purpose of the paper is to find a speed control structure with two degrees of freedom robust against drive parameters variations. Application of structure model following control (MFC) and fuzzy technique in the controller of PI type creates proper non‐linear characteristics, which ensures controller robustness.

Design/methodology/approach

The use of proper structure with two degrees of freedom and non‐linear characteristic introduced by fuzzy technique ensures the robustness of the speed control system. The paper proposes a novel approach to MFC synthesis to be performed in two stages. The first stage consists in the set value of P type controller of model and the process controller simultaneously should be designing by fuzzy technique. At the second stage of the synthesis consist in tuning parameters of process fuzzy controller by the swarm of particles method (particle swarm optimization) on the basis of a defined quality index formulated in the paper. The synthesis is performed using simulation techniques and subsequently the behavior of a laboratory speed control system is validated in the experimental setup. The control algorithms of the system are performed by a microprocessor floating point DSP control system.

Findings

Use of proper structure with two degrees of freedom of the non‐linear fuzzy controller guarantees expected robustness and improves the dynamics of speed control significantly.

Research limitations/implications

The proposed structure of MFC was tested on a single machine under well‐defined conditions. Further investigations are required before any industrial applications.

Practical implications

The proposed controller synthesis and its results may be very helpful in robotic system where changing of system parameters is characteristic for many industrial robots and manipulators.

Originality/value

The paper proposes an original method of synthesis of robust system with two degrees of freedom system validated by simulation and experimental investigations.
Calculation of copper losses in resistance spot welding transformer with space‐ and time‐dependent current density distribution, FEM and measurements
Authors: Popović Jelena , Dolinar Drago , Štumberger Gorazd , Klopčič Beno
Published: June 2011

Purpose

So far the proposed analytical methods for calculation of copper losses are rather simplified and do not include the time component in the basic partial differential equations, which describe current density distribution. Moreover, when the physical parameters of the transformer (wire dimensions) are out of the certain range, the current density distribution approaches infinity. The purpose of this paper is to offer a generally applicable analytical method. The main goal of the proposed modification of the solution to the current density is improvement of the accuracy and stability of the analytical results.

Design/methodology/approach

This paper deals with the calculation of copper losses with various methods, which are based on a time‐dependent electromagnetic field. Analytical method is based on Maxwell equations and Helmholtz equation. Numerical calculation is performed with finite element method (FEM).

Findings

Analytical method is a very accurate and it gives results, which are very similar to the actual behaviour of the current density in the winding. However, the FEM analysis is easier to comprehend, but yet very dependent on input parameters.

Research limitations/implications

The numerical analysis may not be accurate enough, because of the problems with the oscillation of the output welding current amplitude. To calculate copper losses correctly, the output welding current must be equal in all test cases, especially during the measurements.

Originality/value

When the physical properties exceed a certain range, the copper losses of the analyzed welding transformer cannot be calculated with existing analytical methods. The new analytical approach gives a far more realistic solution to the current density distribution and improves the accuracy and stability of the results.
Determination of flux density produced by multilevel inverters in CM voltage filter
Authors: Smoleński Robert , Kempski Adam , Bojarski Jacek , Leżyński Piotr
Published: June 2011

Purpose

The purpose of this paper is to evaluate the conditions in which a saturation of the common mode (CM) choke might appear to be essential for proper design of the CM voltage filters. This paper presents a method for the determination of a CM choke flux density produced by multilevel inverters with carrier‐based modulations.

Design/methodology/approach

The proposed combination of secant and tangent methods allows efficient and high‐resolution determination of the CM voltage waveforms produced at the output of the multilevel inverters with commonly used carrier‐based modulations.

Findings

The presented results show that the application of a five‐level inverter with specific modulation causes a decrease of the maximum flux density, down to 15 per cent of the maximum level of the flux density reached in a two‐level inverter. The proposed, dedicated approximation method provides an accuracy of the root estimation better by about three orders for a comparable number of the function calls in comparison with Brent's method.

Practical implications

The presented theoretical evaluations make possible the determination of the maximum expected value of the flux density produced by multilevel inverters with various types of carrier‐based modulations, which allows a reduction in dimensions, weight and cost of CM chokes applied in CM voltage compensators.

Originality/value

In the paper, the new formulas that describe the placement of triangular carrier functions for commonly used multilevel inverters have been presented. In order to avoid accumulation of the estimation error, during determination of the CM voltage time integral, a dedicated, efficient method of roots approximation has been developed.
Rotor surface losses in an I‐converter‐fed synchronous generator considering saturation
Authors: Vogel Roman , Kulig Stefan
Published: June 2011

Purpose

Operation of synchronous machines in the power range of several 10 MW with variable speed up to 7,000 rpm using a current converter is, thanks to the development of power switches, possible and economically reasonable today. However, current harmonics, produced by converter, generate additional losses, especially eddy current losses on the rotor surface are produced by the converter, which strongly depend on the rotor permeability. The purpose of this paper is to show that an accurate machine modeling is required, in order to consider the nonlinearity of electromagnetic processes inside.

Design/methodology/approach

This paper concentrates on the determination of the rotor surface losses in a three‐phase turbogenerator feeding a current converter. Saturation of rotor steel is taken into account using a transient finite element method model of the machine, coupled with a converter model.

Findings

A detailed analysis of the damper currents and losses in a turbogenerator operating with a frequency converter is presented. The effectivenes of damper winding modifications, concerning the eddy current loss reduction in the rotor surface, is depicted.

Practical implications

The introduced modelling technique presents an accurate electromagnetic modelling of an I‐converter‐fed synchronous generator with massiv poles, which is fed by a current converter and so has to sustain additional eddy current losses in the rotor surface. In this way, the amount and distribution of these losses are evaluated more accurately which allows a more efficient design of the damper winding as well as machine cooling system.

Originality/value

Some researchers have made contributions to the analysis of current converter‐fed synchronous machine, regarding terminal behaviour of the machine. This paper focuses on eddy current losses on the rotor surface, considering the time and space dependent saturation aspect in the machine, particularly in the rotor.
Transport properties and current flow patterns in homogeneous strongly anisotropic materials
Authors: Chippendale Richard D. , Golosnoy Igor O. , Lewin Paul L. , Sykulski Jan K.
Published: June 2011

Purpose

The purpose of this paper is to investigate and explain the unexpected current flow patterns and twisting equipotential surfaces observed in strongly anisotropic materials.

Design/methodology/approach

Potential distributions and current flow paths in highly anisotropic composite materials were studied via numerical simulation and experimentally. Simplified composite panels with two plyes were analysed using a finite‐element model; the predictions were then confirmed experimentally.

Findings

The unexpected twisting equipotential surfaces and current flow patterns were found to be consistent with minimising of Joule heat release in the material. Numerical modelling suggests that the twisted profiles of the potential are highly sensitive to the anisotropic electrical conductivity.

Originality/value

This paper discusses the reverse current flows witnessed in a two‐layer anisotropic system. Such behaviour has never been predicted or observed experimentally before. The reported results will be of interest to anyone who is considering using anisotropic materials such as carbon fibre composites which might experience applied potential difference, such as lightning strikes.
Optimisation of a tubular linear machine with permanent magnets for wave energy extraction
Authors: Parel Thomas S. , Rotaru Mihai D. , Sykulski Jan K. , Hearn Grant E.
Published: June 2011

Purpose

The purpose of this paper is to optimise the cost‐based performance of a tubular linear generator and to minimise cogging forces.

Design/methodology/approach

Optimisation of a tubular linear generator with longitudinal flux topology has been undertaken using a finite element method. The computational models used have been verified experimentally.

Findings

The use of an oversized stator linear generator design as opposed to an oversized translator design has the potential to increase the output electromotive force per unit material cost by 25 per cent for slotless iron core topologies and approximately 14 per cent for air core topologies. For cogging force minimisation, optimisation of the length of the stator core is an effective technique for both oversized stator and oversized translator constructions. Comparisons of magnet materials also indicate that the higher cost of rare earth magnets to ferrites is compensated by their superior specific performances.

Originality/value

In this paper, a broader range of design parameters than in previous investigations has been optimised for the slotless iron core and air core topologies. The result relating to cogging force reduction and cost savings (in particular) has the potential to make direct drive wave energy extraction a more competitive technology in terms of reliability and cost.
A new DTC control for PMSM with torque ripple minimization and constant switching frequency
Authors: Sikorski Andrzej , Grodzki Rafał
Published: June 2011

Purpose

The aim of the paper is to conduct an analytical study of the two new methods of the permanent magnet synchronous motor torque and flux direct control with the predictive non‐linear torque and flux controller.

Design/methodology/approach

The method is based on the prediction of the torque and flux error vector in order to minimize the torque ripple and ensure the constant switching frequency.

Findings

The proposed methods ensure the torque and flux error vector minimization, reduction of the torque ripples, and constant switching frequency without deterioration of the dynamic properties of the standard direct torque control (DTC).

Originality/value

An innovative predictive DTC method is presented. The correctness of the analysis and main assumptions, as well as the expected final results have been verified in simulation.
Adaptive stabilization for generator excitation system
Authors: Ritonja Jožef
Published: June 2011

Purpose

The purpose of this paper is to develop a controller for damping of oscillations of a synchronous generator connected to the electric network. The goal is to determine the configuration of the controller and to set up the procedure for determination of the controller parameters.

Design/methodology/approach

On the basis of the analytical and numerical analysis of the so‐far proposed stabilizers, the new directions towards improved and efficient stabilizer have been established. The advantage of the proposed approach has been confirmed with simulations and experimental results.

Findings

Three main contributions can be highlighted: on the basis of the synchronous generator analysis, it is shown that the conventional power system stabilizer is inappropriate for optimal oscillation damping through the entire operating range; the possibility of application of the model reference adaptive control theory for stabilizer design is confirmed; and the rules have been set up for selection of the stabilizer parameters.

Research limitations/implications

The power system control is rather conservative and does not allow new approaches to the control concepts.

Originality/value

The paper's originality lies in the fact that the proposed adaptive approach for realizing the control system for damping of oscillations is presented completely. The configuration of the controller is presented, as well as the method for determining the adaptation mechanism parameters.
Improved accuracy of electro‐quasistatic simulations of large‐scale 3D high voltage insulators with nonlinear material layers
Authors: Weida Daniel , Steinmetz Thorsten , Clemens Markus
Published: June 2011

Purpose

The purpose of this paper is to analyze the accuracy of finite element method simulations for high voltage equipment featuring resistive field grading.

Design/methodology/approach

In such simulations, the order of the mesh used and the polynomial order of the ansatz functions are varied while maintaining mesh and simulation parameters. The resulting accuracy of the simulations is analyzed by an error convergence study which shows the relative errors against the number of degrees of freedom the computational time and the memory consumption.

Findings

Simulation results of simplified benchmark geometry and applications to large‐scale 3D high voltage equipment are presented herein.

Originality/value

The impact of the order of the mesh and the Ansatz functions are studied for realistic high voltage setups. The paper helps the user of simulation software to choose adequate simulation parameters.
Spectral inductance of the linear motor‐space harmonic analysis
Authors: Utrata Grzegorz , Kaplon Andrzej
Published: June 2011

Purpose

The aim of the paper is to present the methodology of obtaining an approximate equivalent circuit composed of lumped parameters which describes an electromagnetic state of induction machines (IMs) with solid secondary. Higher space harmonic field components are taken into account. The proposed method of machine model constructing is useful for solving electrodynamics states of solid secondary IMs, as well linear machines.

Design/methodology/approach

A determination of equivalent circuit parameters of a polyharmonic machine is divided into two steps. In the first step, frequency plots of the spectral inductances are derived – for each of the space harmonic components – from an electromagnetic field distribution calculated by means of the finite element method. In the second step, each of the spectral inductances are represented by the operational inductances which corresponds to the equivalent circuit composed of parallel connected the magnetizing inductance and branches consisting of resistance and inductance connected in series.

Findings

The proposed method allows the construction of the approximate equivalent circuit with lumped parameters which enables to solve electrodynamic states of solid secondary IMs, as well linear machines. The machine model has been derived with consideration of the higher space harmonic field components.

Research limitations/implications

Saturation effects of a magnetic circuit and an unbalance of phase currents have not been taken into account.

Originality/value

The paper shows the method of constructing a machine field‐circuit model. Lumped parameters of the model have been derived using frequency characteristics of the stator spectral inductance with consideration of the higher space harmonic field components.
Completely online group formation and development: small groups as socio‐technical systems
Authors: Goggins Sean P. , Laffey James , Gallagher Michael
Published: June 2011

Purpose

This paper has two purposes. First, to provide insight into the formation of completely online small groups, paying special attention to how their work practices develop, and how they form identity. Second, to pursue conceptual development of a more multi‐level view of completely online group experience, which can be made visible through analysis of the unique interaction logging system used in this study.

Design/methodology/approach

The authors conduct a mixed methods study that integrates interviews, grounded theory analysis, case study methods and social network analysis to build a multi‐layered view of completely online group and community development.

Findings

Completely online group formation is explicated as a socio‐technical system. The paper identifies themes of tool uptake and use, and patterns of interaction that accompany group formation and development of completely online group practices. These patterns show little respect for the boundaries of space and time. It then shows how groups who are paired together for two non‐sequential activities develop a common internal structural arrangement in the second activity, and are viewable as groups in the larger course context in four of six cases.

Research limitations/implications

The time bounded nature of the group and community, combined with the educational context limit the generalizability of these findings.

Practical implications

The study shows how completely online group development can be made visible. Managers of work teams and teachers who work with classrooms in completely online contexts need to recognize the dynamic structure and interaction practices of completely online teams.

Originality/value

First, little research has been conducted on completely online group formation. Second, a conceptual understanding of how group members relate to one another and how groups interact with other groups in the same socio‐technical context is not explored in prior work. Third, the paper performs this analysis including data from rich, contextualized usage logs, which enables greater insight into online group interactivity than prior research.
Employee management and service provision: a conceptual framework
Authors: Blount Yvette
Published: June 2011

Purpose

The purpose of this paper is to provide a way of thinking about the technical and social subsystems in the context of e‐commerce adoption.

Design/methodology/approach

An interpretive research approach was used to investigate the employee management issues in service industries as they implemented B2C e‐commerce. Two case studies were selected, both retail banks in Australia. One case study was a major bank, the other a smaller bank in a niche market.

Findings

Employees who interact with customers using B2C technologies require different levels of skill and capability than those required in face‐to‐face interactions. This has implications for human resource management processes such as job design, recruitment and retention, performance management and training.

Research limitations/implications

The study was small in scale and therefore limited in scope. Other service organisations and industries may have quite different information ecologies and business strategies.

Practical implications

The coactive commerce system provides a concrete way for researchers and practitioners to better align technology, customers and employees to achieve competitive advantage.

Social implications

This research shows that it is important to understand B2C e‐commerce technologies in conjunction with business practices and in their broader context. It is important to understand how a service organisation's business strategy, technology strategy, business processes and employee management work together to provide an appropriate level of service to customers and achieve sustainable competitive advantage and strategic positioning. This is a complex set of factors.

Originality/value

The coactive commerce system extends the socio‐technical framework to provide a more explicit way to analyse both the social and technical subsystems in an organisation by integrating the human resource management aspects into the theoretical mix in the electronic commerce and information systems literature. This is important because the employee interaction with the customer is the way the customer perceives the organisation.
Why don't more women major in information systems?
Authors: Croasdell David , McLeod Alexander , Simkin Mark G.
Published: June 2011

Purpose

Increasing enrollments in colleges of business have not been matched by women majoring in the field of information systems (IS). This paper aims to explore reasons why women choose not to major in information technology disciplines and to suggest potential solutions.

Design/methodology/approach

The authors used a behavioral model based on the theory of reasoned action and a survey of the students enrolled in six sections of a college‐wide MIS course to help them answer the fundamental question “Why don't more women major in information systems?” They also used partial least squares analysis to estimate the parameters of the model and the results of several open‐ended survey questions to validate their statistical findings, leading to a richer triangulation of study results.

Findings

The study found that a “genuine interest in IS” and the “influence of family” most account for a woman's decision to major in information systems. Equally important are those items that did not appear to attract females, including such matters as “job‐related factors” or the “influence of fellow students or friends”. These findings have important recruitment and retention implications as well as suggesting some avenues for further study.

Originality/value

The analyses suggest that there is much faculty and business recruiters can do to encourage more females to major in IT‐related disciplines. One is to encourage women to develop more interest in the field. Another is to create more study options for women with hard‐science talents who want to pursue technologically‐intensive careers. Finally, teachers, academic institutions, and employers might find it useful to address some of the misconceptions that women might have about IT‐related jobs – for example, that IT jobs are only for males or computer geeks – and stress the many positive dimensions of IT career paths.
A literature review of maintenance performance measurement
Authors: Simões J.M. , Gomes C.F. , Yasin M.M.
Published: June 2011

Purpose

This research aims to examine the relevant literature related to maintenance performance measurement in the manufacturing sector. In the process, innovative approaches and models utilized to measure and manage maintenance performance in manufacturing operational settings are classified and examined. Based on this investigation, future research directions and themes are identified.

Design/methodology/approach

A database of 251 peer‐reviewed publications, published during the last 30 years, was utilized for the purpose of this research. The published works included contributions from both practitioners and scholars.

Findings

This literature review‐based research revealed important themes related to evolution of maintenance performance management. These themes focus on the effective utilization of maintenance resources, information systems support, and human factor management. Based on this literature review, a conceptual framework, which traces the different operational and organizational facets of the evolution of maintenance performance management, is offered.

Research limitations/implications

Based on the findings of this study, it is concluded that the area of maintenance performance and management is in need of more future systematic research efforts aimed at solidifying theoretical constructs and promoting the utilization of more practical applications.

Practical implications

Findings derived from this investigation have relevant manufacturing implications. In this context, understanding the different approaches to maintenance performance measurement and management, as utilized in manufacturing organizations, is critical to these organizations' performance improvement efforts.

Originality/value

Understanding the types and scopes of the different approaches and models utilized to manage and measure maintenance performance in manufacturing operational settings is important in light of the growing competitiveness of the manufacturing sector.
Practical application of the Decision Making Grid (DMG)
Authors: Aslam‐Zainudeen Nafisah , Labib Ashraf
Published: June 2011

Purpose

The purpose of this paper is to explore the applicability of the Decision Making Grid (DMG) and its usefulness, in practice, in the maintenance of rolling stock in the railway industry. The Class 319 fleet operated by First Capital Connect (FCC) is used to demonstrate the application of the DMG.

Design/methodology/approach

The level of use of the data recorded in the CMMS, in the decision making process for reviewing, and updating the maintenance policy, was established through discussions with senior management at FCC. Available decision support systems were then researched, with emphasis on the DMG concept. The advantages of using the DMG and its application in the real world using data for the Class 319 fleet were then explored and are discussed in this paper.

Findings

This paper discusses the value in applying the DMG concept in the decision‐making process for prioritising systems and the work that should be done to ensure the maintenance policy takes into account the performance of the units of rolling stock against the most important criteria for FCC. Through the research carried out, it was established that the existing CMMS already records the data required for the application of the DMG, although in itself, the CMMS does not have any decision support capabilities.

Originality/value

Although a number of different CMMSs are used in the railway industry, few or none of these are capable of providing decision support for maintenance. This paper explores the use of the DMG concept to demonstrate the use of data recorded in the CMMS to develop a more effective maintenance policy and to determine exactly which maintenance activities need to be carried out in order to remedy the worst performing systems in terms of the most important criteria as identified by the business.
A framework for strategic planning in maintenance
Authors: Al‐Turki Umar
Published: June 2011

Purpose

The purpose of this study is to introduce a framework for developing a maintenance strategic plan that links the maintenance function with the corporate strategy and integrates it with other functional areas. Within the proposed framework, a systematic process for maintenance strategic planning is described and key success factors that need special attention are identified.

Design/methodology/approach

An analytical methodology is adopted to develop a systematic approach for implementing the framework

Findings

The study finds that the involvement of major stakeholders as well as top management commitment is essential for the successful development of a maintenance strategic plan. The process of development of the strategic plan in maintenance differs from other areas because of its intangible benefits to the organization and special type of stakeholders. More emphasis should be put into handling senior management and other partners within the organization.

Practical implications

Senior maintenance managers and strategy developers may benefit from this study in developing their own plans. The process of developing the plan is well explained in a systematic manner that will drive the developers throughout the whole process.

Originality/value

The literature of strategic management and strategic issues in maintenance is summarized to set the foundation for the framework and to enrich the process of strategic planning with alternative strategies for different issues that will help in selecting the most appropriate strategy. The value of the paper is in its framework that puts elements of strategic planning together in an integrated framework.
Practical application of an Analytic Hierarchy Process for the improvement of the warranty management
Authors: González Díaz V. , Gómez Fernández J. , Crespo Márquez A.
Published: June 2011

Purpose

This paper will be focused in one of the stages included in a reference framework proposed for the improvement of the warranty management. Particularly, the Analytic Hierarchy Process (AHP) is a multi‐criteria decision‐making method that will be depicted throughout this document and applied to a particular case study.

Design/methodology/approach

Once the warranty program objectives and strategy are defined, the referred stage here considered will be the Criticality Analysis. Those decisions and actions taken from the warranty program will involve the possibility of a certain deviation from business objectives in terms of profit losses, redirection of resources, possible delays etc., or the use of assembly pieces as spares, among others.

Findings

The application is required of a technique which helps systematically to decide which assets should have priority related to the management of the warranty program, in accordance of course with the existing program strategy.

Practical implications

The paper will show how this method can help and improve the decision‐making related to some aspect of the warranty management, obtaining as a result a criticality matrix, which offers a prioritized view of warranty issues, which allow us to align after sales actions with the business targets.

Originality/value

This paper aims to explore different aspects related to the Analytic Hierarchy Process (AHP), which can influence in the management of warranty assistances. In the process of warranty management for a specific product, many decisions and actions appear presenting a great impact on the total cost of the product warranty service. The paper contains an example study where AHP concepts are applied in a simple way in order to provide a practical application view of the theoretical development, useful to after sales managers as a decision‐making tool.