Bjarne Bergquist

Luleå University of Technology | LTU · Department of Business Administration, Technology and Social Sciences (ETS)

This paper illustrates a generalisable experimental approach to assess the causal effects of track maintenance actions. In our case, we assess the causal effects of tamping on railway track geometry. The tamping was conducted during the regular autumn tamping campaign in 2022 on track section 118 of the Swedish Iron ore line “Malmbanan”. The experi...

The accuracy of the measurement system is vital for reliable process monitoring using statistical process control charts. The applied chart’s effectiveness depends on the measurement system's performance. Measurement uncertainty can lead to incorrect decisions like unnecessary stops or failure to intervene. In this paper, we investigated the effect...

Timely planning and scheduling of railway infrastructure maintenance interventions are crucial for increased safety, improved availability, and reduced cost. We propose a data‐driven decision‐support framework integrating track condition predictions with tactical maintenance planning and operational scheduling. The framework acknowledges prediction...

Prognostics is a vital application for Industrial AI. However, data quality sometimes does not suit regular prediction models. For instance, data sampling procedures occasionally include irregular sampling, and many prognostic methods require evenly sampled time series. One example is measurement trains that travel along the railway line, measuring...

Railway track maintenance and renewal are vital for railway safety, train punctuality, and travel comfort. Therefore, having cost-effective maintenance is critical in managing railway infrastructure assets. There has been a considerable amount of research performed on mathematical and decision support models for improving the application of railway...

Quality management (QM) has shown an impressive ability to update and evolve. The purpose of this paper is to highlight themes that have been identified as vital and important for research projects within QM during the coming decade. The paper is also an attempt to initiate research for the emerging 2030 agenda for QM, here referred to as 'Quality...

The concurrent use of statistical process control and engineering process control involves monitoring manipulated and controlled variables. One multivariate control chart may handle the statistical monitoring of all variables, but observing the manipulated and controlled variables in separate control charts may improve understanding of how disturba...

The active radio frequency identification (RFID) technique is used for in-situ measurement of acceleration and temperature in the distribution chain of iron ore pellets. The results of this paper are based on two experiments, in which active RFID transponders were released into train wagons or product bins. RFID exciters and readers were installed...

Data of sufficient quality, quantity and validity constitute a sometimes overlooked basis for eMaintenance. Missing data, heterogeneous data types, calibration problems, or non-standard distributions are common issues of operation and maintenance data. Railway track geometry data used for maintenance planning exhibit all the above issues. They also...

Engineering process control and high-dimensional, time-dependent data present great methodological challenges when applying statistical process control (SPC) and design of experiments (DoE) in continuous industrial processes. Process simulators with an ability to mimic these challenges are instrumental in research and education. This article focuse...

From its inception, the field of quality management (QM) has been characterised by practice-driven development. Although QM has reached maturity as a field of research based on empirical enquiry, its practitioners still struggle to adapt QM implementations to reap their benefits. This study aims to identify their challenges to better understand how...

Researchers have promoted statistical improvement methods as essential for product and process improvement for decades. However, studies show that their use has been moderate at best. This study aims to assess the use of statistical process control (SPC), process capability analysis, and design of experiments (DoE) over time. The study also highlig...

Industrial manufacturing processes often operate under closed-loop control, where automation aims to keep important process variables at their set-points. In process industries such as pulp, paper, chemical and steel plants, it is often hard to find production processes operating in open loop. Instead, closed-loop control systems will actively atte...

When principal component analysis (PCA) is used for statistical process monitoring it relies on the assumption that data are time independent. However, industrial data will often exhibit serial correlation. Dynamic PCA (DPCA) has been suggested as a remedy for high-dimensional and time-dependent data. In DPCA the input matrix is augmented by adding...

Traditional practice within railway maintenance is based on engineering knowledge and practical experience, which are documented in regulations. This practice is often time-based, but can also be condition-based by combining time-based inspections with condition-based actions depending on the inspection results. However, the logic behind the result...

The degradation processes affecting railway track condition depends both on the resistance of the track and on the stresses subjected to it. Regarding the stresses, both their magnitudes and cycles are of importance when considering the degradation. Furthermore, the stresses have some regularity and variability in the time domain, while the degrada...

Purpose – The purpose of this paper is to identify and explore important quality-related challenges facing organizations, and investigate how current excellence models incorporate these challenges. Design/methodology/approach – The paper is based on a Delphi study of Swedish organizations. Forty-nine challenges were generated and ranked according t...

Quality Management is considered to be suitable as support for the integration of sustainability considerations in areas such as product development. The purpose of this paper is to review research in which Quality Management methods, tools or practices have been used in conjunction with sustainable development initiatives. We have identified four...

Rail breaks are safety critical failures within railway that may result in derailment, but also delays and cancelled trains. Maintenance is important to both manage the causes of rail breaks and to reduce their unwanted consequences. The purpose of this study is to explore the relationship between maintenance practice, rail breaks and their consequ...

This paper presents a tentative analysis method for unreplicated factorial designs where regular statistical experimental analysis cannot be used. The methodology is demonstrated through the analysis of an unreplicated two-level, two-factor factorial experiment performed in a continuous production process where the process was not in statistical co...

This paper presents a control chart approach for monitoring, diagnostics, and prognostics to support condition-based maintenance (CBM) using condition data on linear railway infrastructure assets. The condition data were obtained from regular inspections conducted using a railway track measurement wagon. The condition data were statistically analys...

This paper presents ideas and observations about the infrequent use of factorial experimental designs; although the ideas presented are inspired by a case study, the paper is also conceptual in nature. The ideas build on the experimental practices at a large Swedish process industry manufacturer, where these practices were discussed with engineers...

This paper aims to develop a conceptual framework for testing the motivation to engage in improvement work. The framework is based on Ajzen's theory of planned behavior (TPB), that we suggest can be used to facilitate the implementation of improvement programmes. By using the model and probing intentions, attitudes, norms and perceived ability rela...

Purpose – The purpose of this paper is to summarize previously reported benefits, drawbacks and important aspects for implementation of performance-based logistics (PBL), and to identify knowledge gaps. Design/methodology/approach – This is a literature review based on 101 articles. The reviewed articles are relevant to PBL in particular, but also...

Mould oscillation is needed to reduce friction and thus prevent sticking and breakout of the liquid metal during casting. However, this oscillation is known to cause surface defects in the solidified steel slabs, so called oscillation marks. In this paper, the depth and the depth variation of these oscillation marks were studied using a two-level f...

Condition assessment is crucial to optimize condition-based maintenance actions of assets such as railway infrastructure, where a faulty state might have severe consequences. Hence, railways are regularly inspected to detect failure events and prevent the inspected item (e.g. rail) to reach a faulty state with potentially safety critical consequenc...

Dynamic processes exhibit a time delay between the disturbances and the resulting process response. Therefore, one has to acknowledge process dynamics, such as transition times, when planning and analyzing experiments in dynamic processes. In this article, we explore, discuss, and compare different methods to estimate location effects for two-level...

The purpose of this article is to describe how Quality Management (QM) is perceived today by scholars at three Swedish universities, and into what QM is expected to develop into in twenty years. Data were collected through structured workshops using affinity diagrams with scholars teaching and performing research in the QM field. The results show t...

Traceability is normally difficult to achieve in continuous processes, since there are no natural batch structures. In this article, we demonstrate flow-based simulation using process data to improve traceability in a continuous pelletising process. Using the simulation model, the engineers could test the impacts of process disturbances, identify c...

The ability to track and trace products in a production process and in the transportation chain from supplier to customers is important for quality control and process improvements. However, good traceability is often difficult achieve for continuous process products as well as for batch produced products where batches intermix. In this paper, guid...

Process industries often have features that differ from other businesses, such as round‐the‐clock production and costly and specialized production processes—features that have not been dealt with in the project management literature. We highlight and identify the complexity of R&D projects in the Swedish process industry and its interrelated proces...

Traceability is important for identifying the root causes of production-related quality problems. Traceability can often be reached by adding identification markers on products, but this is not a solution when the value of the individual product is much lower than the incurred cost of a marking system. This is the case for continuous production of...

This article proposes a Bayesian procedure to calculate posterior probabilities of active effects for unreplicated two-level factorials. The results from a literature survey are used to specify individual prior probabilities for the activity of effects and the posterior probabilities are then calculated in a three-step procedure where the principle...

Process dynamics is an important consideration during the planning phase of designed experiments in dynamic processes. After changes of experimental factors, dynamic processes undergo a transition time before reaching a new steady state. To minimize experimental time and reduce costs and for experimental design and analysis, knowledge about this tr...

Purpose The purpose of this paper is to present a study of how Six Sigma influences job satisfaction among employees at three large companies with manufacturing units in Sweden that have used different implementation strategies. Design/methodology/approach The study was performed using a survey distributed to those affected by the implementation a...

This paper describes a joint project started by citizens, trade life and local government of the Swedish municipality of Jokkmokk to create a positive societal development based on the tenets of Total Quality Management. The project had duration of two years, and did also include a parallel effort made in Mansfield in the United Kingdom, although t...

Purpose – The purpose of this paper is to discuss the ongoing development of quality management, and whether the concepts being discussed can be agreed – and what influence this might have on the quality movement and quality practice. Design/methodology/approach – Literature review and meta-analysis of current trends has been used to create a conce...

Discontinuous processes dominate experimental applications in practice as well as in literature. Continuous processes constitute a significant part of goods production, and the need to gain knowledge using experiments are as relevant in such environments as in, for example, parts production. We argue that the characteristics of continuous processes...

Students taking courses in quality management at Luleå University of Technology receive extensive education in statistical methods. To improve the education and to understand what kind of competence students need when they graduate, a survey was preformed examining how and to what extent the methods Statistical Process Control, Capability Analysis...

For decades now TQM has been a dominant management concept for improving competitiveness and financial results. In recent years, however, TQM seems to have lost some of its nimbus with other concepts and approaches such as Lean Enterprise and Six Sigma launched and increasingly in vogue. The aim of this paper is to look at TQM and Six Sigma, their...

As teachers, the authors are eager to confirm that what they teach is correct and that their topics are both fun and worth studying further. How they make their propositions attractive is, of course, context dependent. This article describes how a one-hour introductory course in design of experiments (DOE) can be used to attract high school student...

Purpose – Total quality management has seen a tremendous rise of popularity in the 1980s and 1990s. Aims to question the effectiveness, utility and use of TQM among many people – practitioners, as well as academics. Design/methodology/approach – Discusses the lack of common interpretations of TQM based on literature study. The answer to the questi...

Filling induced density variations is a problem that has long been overlooked by powder metallurgy scientists. In this paper,densityvariations are addressed, both why they occur and what problems they may cause. A test method, including a test rig, is presented that is able to link several different factors to resulting powder densities. The relati...

Alloy design and choice of process parameters are often tasks where different investigations lead in different directions and the process of selecting the best parameter settings is difficult. Multivariate statistics are capable of bringing order in such situations, and here data from four different investigations on the Fe–P–C system are collected...

One of the main purposes of water atomisation is to keep the powder size distribution within a close range. The process is difficult to monitor and thus the state of today's process control is poor. To investigate this process, both a laboratory scale and an industrial scale atomisation facility were modelled where melt flow and thermal flow were i...

Trace amounts of surfactants have an acute influence on measured surface tension of melts and may influence viscosity. A water atomisation experiment was performed to investigate if variations of these elements could affect quality. Effects of water pressure, melt superheat, and sulphur content, iron scrap oxygen content, and aluminium content were...

A robust design investigation was conducted on a Fe-P alloy system to understand how sintering variables interact with green compact variables to obtain a robust process. It was shown that the sensitivity with regard to disturbances in composition or density can be reduced for the Fe-P system. A qualitative measure of the importance of different pr...

To reduce dimensional and mechanical property variations in a component manufactured from a phosphorus alloyed P/M steel, a design of experiments approach was used to identify the most important green compact variations. Responses evaluated were unnotched Charpy impact energy, total dimensional change, and sintered density. The experimental array w...

In continuous process industries, large investments in automated process control systems are made to reduce variance, but the variance in key process parameters often remain unchanged. One reason is that the operators often lack tools to assess the impact of process changes on the final product properties. Dynamic simulation could be used to estima...