Computer integrated manufacturing (CIM) and the principle of business control

In response to the increasing international competitiveness, many manufacturing businesses are rethinking their management strategies and philosophies towards achieving a computer integrated environment. The explosive growth in Advanced Manufacturing Technology (AMI) has resulted in the formation of functional "Islands of Automation" such as Computer Aided Design (CAD), Computer Aided Manufacturing (CAM), Computer Aided Process Planning (CAPP) and Manufacturing Resources Planning (MRPII). This has resulted in an environment which has focussed areas of excellence and poor overall efficiency, co-ordination and control. The main role of Computer Integrated Manufacturing (CIM) is to integrate these islands of automation and develop a totally integrated and controlled environment. However, the various perceptions of CIM, although developing, remain focussed on a very narrow integration scope and have consequently resulted in mere linked islands of automation with little improvement in overall co-ordination and control. This thesis, that is the research described within, develops and examines a more holistic view of CIM, which is based on the integration of various business elements. One particular business element, namely control, has been shown to have a multi-facetted and underpinning relationship with the CIM philosophy. This relationship impacts various CIM system design aspects including the CIM business analysis and modelling technique, the specification of systems integration requirements, the CIM system architectural form and the degree of business redesign. The research findings show that fundamental changes to CIM system design are required; these are incorporated in a generic CIM design methodology. The affect and influence of this holistic view of CIM on a manufacturing business has been evaluated through various industrial case study applications. Based on the evidence obtained, it has been concluded that this holistic, control based approach to CIM can provide a greatly improved means of achieving a totally integrated and controlled business environment. This generic CIM methodology will therefore make a significant contribution to the planning, modelling, design and development of future CIM systems.

Uses of frontier efficiency methodologies and multi-criteria decision making for performance measurement in the energy sector

Guest editorial Ali Emrouznejad is a Senior Lecturer at the Aston Business School in Birmingham, UK. His areas of research interest include performance measurement and management, efficiency and productivity analysis as well as data mining. He has published widely in various international journals. He is an Associate Editor of IMA Journal of Management Mathematics and Guest Editor to several special issues of journals including Journal of Operational Research Society, Annals of Operations Research, Journal of Medical Systems, and International Journal of Energy Management Sector. He is in the editorial board of several international journals and co-founder of Performance Improvement Management Software. William Ho is a Senior Lecturer at the Aston University Business School. Before joining Aston in 2005, he had worked as a Research Associate in the Department of Industrial and Systems Engineering at the Hong Kong Polytechnic University. His research interests include supply chain management, production and operations management, and operations research. He has published extensively in various international journals like Computers & Operations Research, Engineering Applications of Artificial Intelligence, European Journal of Operational Research, Expert Systems with Applications, International Journal of Production Economics, International Journal of Production Research, Supply Chain Management: An International Journal, and so on. His first authored book was published in 2006. He is an Editorial Board member of the International Journal of Advanced Manufacturing Technology and an Associate Editor of the OR Insight Journal. Currently, he is a Scholar of the Advanced Institute of Management Research. Uses of frontier efficiency methodologies and multi-criteria decision making for performance measurement in the energy sector This special issue aims to focus on holistic, applied research on performance measurement in energy sector management and for publication of relevant applied research to bridge the gap between industry and academia. After a rigorous refereeing process, seven papers were included in this special issue. The volume opens with five data envelopment analysis (DEA)-based papers. Wu et al. apply the DEA-based Malmquist index to evaluate the changes in relative efficiency and the total factor productivity of coal-fired electricity generation of 30 Chinese administrative regions from 1999 to 2007. Factors considered in the model include fuel consumption, labor, capital, sulphur dioxide emissions, and electricity generated. The authors reveal that the east provinces were relatively and technically more efficient, whereas the west provinces had the highest growth rate in the period studied. Ioannis E. Tsolas applies the DEA approach to assess the performance of Greek fossil fuel-fired power stations taking undesirable outputs into consideration, such as carbon dioxide and sulphur dioxide emissions. In addition, the bootstrapping approach is deployed to address the uncertainty surrounding DEA point estimates, and provide bias-corrected estimations and confidence intervals for the point estimates. The author revealed from the sample that the non-lignite-fired stations are on an average more efficient than the lignite-fired stations. Maethee Mekaroonreung and Andrew L. Johnson compare the relative performance of three DEA-based measures, which estimate production frontiers and evaluate the relative efficiency of 113 US petroleum refineries while considering undesirable outputs. Three inputs (capital, energy consumption, and crude oil consumption), two desirable outputs (gasoline and distillate generation), and an undesirable output (toxic release) are considered in the DEA models. The authors discover that refineries in the Rocky Mountain region performed the best, and about 60 percent of oil refineries in the sample could improve their efficiencies further. H. Omrani, A. Azadeh, S. F. Ghaderi, and S. Abdollahzadeh presented an integrated approach, combining DEA, corrected ordinary least squares (COLS), and principal component analysis (PCA) methods, to calculate the relative efficiency scores of 26 Iranian electricity distribution units from 2003 to 2006. Specifically, both DEA and COLS are used to check three internal consistency conditions, whereas PCA is used to verify and validate the final ranking results of either DEA (consistency) or DEA-COLS (non-consistency). Three inputs (network length, transformer capacity, and number of employees) and two outputs (number of customers and total electricity sales) are considered in the model. Virendra Ajodhia applied three DEA-based models to evaluate the relative performance of 20 electricity distribution firms from the UK and the Netherlands. The first model is a traditional DEA model for analyzing cost-only efficiency. The second model includes (inverse) quality by modelling total customer minutes lost as an input data. The third model is based on the idea of using total social costs, including the firm’s private costs and the interruption costs incurred by consumers, as an input. Both energy-delivered and number of consumers are treated as the outputs in the models. After five DEA papers, Stelios Grafakos, Alexandros Flamos, Vlasis Oikonomou, and D. Zevgolis presented a multiple criteria analysis weighting approach to evaluate the energy and climate policy. The proposed approach is akin to the analytic hierarchy process, which consists of pairwise comparisons, consistency verification, and criteria prioritization. In the approach, stakeholders and experts in the energy policy field are incorporated in the evaluation process by providing an interactive mean with verbal, numerical, and visual representation of their preferences. A total of 14 evaluation criteria were considered and classified into four objectives, such as climate change mitigation, energy effectiveness, socioeconomic, and competitiveness and technology. Finally, Borge Hess applied the stochastic frontier analysis approach to analyze the impact of various business strategies, including acquisition, holding structures, and joint ventures, on a firm’s efficiency within a sample of 47 natural gas transmission pipelines in the USA from 1996 to 2005. The author finds that there were no significant changes in the firm’s efficiency by an acquisition, and there is a weak evidence for efficiency improvements caused by the new shareholder. Besides, the author discovers that parent companies appear not to influence a subsidiary’s efficiency positively. In addition, the analysis shows a negative impact of a joint venture on technical efficiency of the pipeline company. To conclude, we are grateful to all the authors for their contribution, and all the reviewers for their constructive comments, which made this special issue possible. We hope that this issue would contribute significantly to performance improvement of the energy sector.

Developing a decomposable measure of profit efficiency using DEA

In for-profit organizations efficiency measurement with reference to the potential for profit augmentation is particularly important as is its decomposition into technical, and allocative components. Different profit efficiency approaches can be found in the literature to measure and decompose overall profit efficiency. In this paper, we highlight some problems within existing approaches and propose a new measure of profit efficiency based on a geometric mean of input/output adjustments needed for maximizing profits. Overall profit efficiency is calculated through this efficiency measure and is decomposed into its technical and allocative components. Technical efficiency is calculated based on a non-oriented geometric distance function (GDF) that is able to incorporate all the sources of inefficiency, while allocative efficiency is retrieved residually. We also define a measure of profitability efficiency which complements profit efficiency in that it makes it possible to retrieve the scale efficiency of a unit as a component of its profitability efficiency. In addition, the measure of profitability efficiency allows for a dual profitability interpretation of the GDF measure of technical efficiency. The concepts introduced in the paper are illustrated using a numerical example.

Cost-based pricing in the NHS internal market : accounting choices and the achievement of economic efficiency

Since 1988, quasi-markets have been introduced into many areas of social policy in the UK, the NHS internal market is one example. Markets operate by price signals. The NHS Internal Market, if it is to operate efficiently, requires purchasers and providers to respond to price signals. The research hypothesis is - cost accounting methods can be developed to enable healthcare contracts to be priced on a cost-basis in a manner which will facilitate the achievement of economic efficiency in the NHS internal market. Surveys of hospitals in 1991 and 1994 established the cost methods adopted in deriving the prices for healthcare contracts in the first year of the market and three years on. An in-depth view of the costing for pricing process was gained through case studies. Hospitals had inadequate cost information on which to price healthcare contracts at the inception of the internal market: prices did not reflect the relative performance of healthcare providers sufficiently closely to enable the market's espoused efficiency aims to be achieved. Price variations were often due to differing costing approaches rather than efficiency. Furthermore, price comparisons were often meaningless because of inadequate definition of the services (products). In April 1993, the NHS Executive issued guidance on costing for contracting to all NHS providers in an attempt to improve the validity of price comparisons between alternative providers. The case studies and the 1994 survey show that although price comparison has improved, considerable problems remain. Consistency is not assured, and the problem of adequate product definition is still to be solved. Moreover, the case studies clearly highlight the mismatch of rigid, full-cost pricing rules with both the financial management considerations at local level and the emerging internal market(s). Incentives exist to cost-shift, and healthcare prices can easily be manipulated. In the search for a new health policy paradigm to replace traditional bureaucratic provision, cost-based pricing cannot be used to ensure a more efficient allocation of healthcare resources.

A priori prediction of aggregation efficiency and rate constant for fluidized bed melt granulation

This paper presents a predictive aggregation rate model for spray fluidized bed melt granulation. The aggregation rate constant was derived from probability analysis of particle–droplet contact combined with time scale analysis of droplet solidification and granule–granule collision rates. The latter was obtained using the principles of kinetic theory of granular flow (KTGF). The predicted aggregation rate constants were validated by comparison with reported experimental data for a range of binder spray rate, binder droplet size and operating granulator temperature. The developed model is particularly useful for predicting particle size distributions and growth using population balance equations (PBEs).

Random distributed feedback fiber laser of ultimate efficiency

We demonstrate a random fiber laser of ultimate efficiency. More than 2 Watts are generated from 0.5W of pump excess over the generation threshold. At higher power, an optical efficiency corresponds to the quantum limit.

Eco-efficiency measurement and material balance principle:an application in power plants Malmquist Luenberger Index

Incorporating Material Balance Principle (MBP) in industrial and agricultural performance measurement systems with pollutant factors has been on the rise in recent years. Many conventional methods of performance measurement have proven incompatible with the material flow conditions. This study will address the issue of eco-efficiency measurement adjusted for pollution, taking into account materials flow conditions and the MBP requirements, in order to provide ‘real’ measures of performance that can serve as guides when making policies. We develop a new approach by integrating slacks-based measure to enhance the Malmquist Luenberger Index by a material balance condition that reflects the conservation of matter. This model is compared with a similar model, which incorporates MBP using the trade-off approach to measure productivity and eco-efficiency trends of power plants. Results reveal similar findings for both models substantiating robustness and applicability of the proposed model in this paper.

A combined neural network and DEA for measuring efficiency of large scale datasets

Data Envelopment Analysis (DEA) is one of the most widely used methods in the measurement of the efficiency and productivity of Decision Making Units (DMUs). DEA for a large dataset with many inputs/outputs would require huge computer resources in terms of memory and CPU time. This paper proposes a neural network back-propagation Data Envelopment Analysis to address this problem for the very large scale datasets now emerging in practice. Neural network requirements for computer memory and CPU time are far less than that needed by conventional DEA methods and can therefore be a useful tool in measuring the efficiency of large datasets. Finally, the back-propagation DEA algorithm is applied to five large datasets and compared with the results obtained by conventional DEA.

A note on the modelling the efficiency of top Arab banks

The major aim of this research is benchmarking top Arab banks using Data Envelopment Analysis (DEA) technique and to compare the results with that of published recently in Mostafa (2007a,b) [Mostafa, M. M. (2007a). Modeling the efficiency of top Arab banks: A DEA–neural network approach. Expert Systems with Applications, doi:10.1016/j.eswa.2007.09.001; Mostafa M. M. (2007b), Benchmarking top Arab banks’ efficiency through efficient frontier analysis, Industrial Management & Data Systems, 107(6) 802–823]. Data for 85 Arab banks used to conduct the analysis of relative efficiency. Our findings indicate that (1) the efficiency of Arab banks reported in Mostafa (2007a,b) is incorrect, hence, readers should take extra caution of using such results, (2) the corrected efficiency scores suggest that there is potential for significant improvements in Arab banks. In summary, this study overcomes with some data and methodology issues in measuring efficiency of Arab banks and highlights the importance of encouraging increased efficiency throughout the banking industry in the Arab world using the new results.

The frontier approach to the measurement of productivity and technical efficiency

In 1957, Farrell proposed to measure technical (in)efficiency as the realised deviation from a frontier isoquant. Since then, the research has developed several methods to derive the production frontier and it has also extended its scope in applying frontier techniques to the measurement of total factor productivity. In this paper, I present the core techniques for the measurement of technical efficiency and productivity based on the notion of frontier and introduce the more recent technological advances in the field.

Development of plasmid dna formulations for application as microspheric dna vaccines

The advent of DNA vaccines has heralded a new technology allowing the design and elicitation of immune responses more adequate for a wider range of pathogens. The formulation of these vaccines into the desired dosage forms extends their capability in terms of stability, routes of administration and efficacy. This thesis describes an investigation into the fabrication of plasmid DNA, the active principle of DNA vaccines, into microspheres, based on the tenet of an increased cellular uptake of microparticulate matter by phagocytic cells. The formulation of plasmid DNA into microspheres using two methods, is presented. Formulation of microspheric plasmid DNA using the double emulsion solvent evaporation method and a spray-drying method was explored. The former approach involves formation of a double emulsion, by homogenisation. This method produced microspheres of uniform size and smooth morphology, but had a detrimental effect on the formulated DNA. The spray-drying method resulted in microspheres with an improved preservation of DNA stability. The use of polyethylenimine (PEI) and stearylamine (SA) as agents in the microspheric formulation of plasmid DNA is a novel approach to DNA vaccine design. Using these molecules as model positively-charged agents, their influence on the characteristics of the microspheric formulations was investigated. PEI improved the entrapment efficiency of the plasmid DNA in microspheres, and has minimal effect on either the surface charge, morphology or size distribution of the formulations. Stearylamine effected an increase in the entrapment efficiency and stability of the plasmid DNA and its effect on the micropshere morphology was dependent on the method of preparation. The differences in the effects of the two molecules on microsphere formulations may be attributable to their dissimilar physico-chemical properties. PEI is water-soluble and highly-branched, while SA is hydrophobic and amphipathic. The positive charge of both molecules is imparted by amine functional groups. Preliminary data on the in vivo application of formulated DNA vaccine, using hepatitis B plasmid, showed superior humoral responses to the formulated antigen, compared with free (unformulated) antigen.

Development of techniques to predict production line efficiency

This industrial based research project was undertaken for British Leyland and arose as a result of poor system efficiency on the Maxi and Marina vehicle body build lines. The major factors in the deterioration of system efficiency were identified as: a) The introduction of a 'Gateline' system of vehicle body build. b) The degeneration of a newly introduced measured daywork payment scheme. By relating the conclusions of past work on payment systems to the situation at Cowley, it was concluded that a combination of poor industrial relations and a lack of managerial control had caused the measured daywork scheme to degenerate into a straightforward payment for time at work. This ellminated the monetary incentive to achieve schedule with the consequence that both inefficiency and operating costs increased. To analyse further the cause of inefficiency, a study of Marina gateline stoppage logs was carried out. This revealed that poor system efficiency on the gateline was caused more by the nature of its design than poor reliability on individual items of' plant. The consideration given to system efficiency at the design stage was found to be negligible, the main obstacles being: a) A lack of understanding pertaining to the influence of certain design factors on the efficiency of a production line. b) The absence of data and techniques to predict system efficiency at the design stage. To remedy this situation, a computer simulation study of' the design factors was carried out from which relationships with system efficiency were established and empirical efficiency equations developed. Sets of tables were compiled from the equations and efficiency data relevant to vehicle body building established from the gateline stoppage logs. Computer simulation, the equations and the tables,when used in conjunction. with good efficiency data, are shown to be accurate methods of predicting production line system.efficiency.

Application of space-charge electrostatic precipitator for collection of oil mist from pyrolysis gases

A novel electrostatic precipitator CAROLA® is developed for collection of fine oil mists. It operates on the principle of unipolar particle charging in the corona discharge and particle precipitation under the field of space charge. The pilot precipitator was tested at different gas temperatures. It is shown that the increase of gas temperature changes the characteristics of the corona discharge and particle size distribution, especially for droplets sub-micron droplets. The CAROLA® precipitator was used for collection of oil mist from pyrolysis gases at the HALOCLEAN® plant. The flow rate of biomass in the HALOCLEAN® plant was 15-30 kg/h. The particle mass concentration in the raw gas was over 100 g/Nm. The operation voltage of the precipitator was 10-12 kV and corona current up to 0,1 mA. Single stage electrostatic precipitator ensured mass collection efficiency 97-99,5% for pyrolysis oil mist.