When principal component analysis (PCA) is used for statistical process monitoring it relies on the assumption that data are time independent. However, industrial will often exhibit serial correlation. Dynamic PCA (DPCA) has been suggested as a remedy high-dimensional and time-dependent data. In DPCA input matrix augmented by adding time-lagged values of variables. building model analyst needs to decide (1) number lags add, (2) given specific lag structure, how many components retain. this...

One of the basic assumptions for traditional univariate and multivariate control charts is that data are independent in time. For latter, many cases, serially dependent (autocorrelated) cross‐correlated because of, example, frequent sampling process dynamics. It well known autocorrelation affects false alarm rate shift‐detection ability charts. However, how Hotelling T 2 chart affected by various cross‐correlation structures different magnitudes shifts mean not fully explored literature. In...

A basic assumption when using principal component analysis (PCA) for inferential purposes, such as in statistical process control (SPC), is that the data are independent time. In many industrial processes, frequent sampling and dynamics make this unrealistic rendering sampled autocorrelated (serially dependent). PCA can be used to reduce dimensionality simplify multivariate SPC. Although there have been some attempts literature deal with PCA, we argue impact of autocorrelation on PCA-based...

This article illustrates a method to measure, visualize, and statistically test tamping effectiveness on track geometry using comparing two different measurement systems: an onboard system mounted regular passenger train specialized system. The proposed analysis can be generalized assess the impact of other maintenance activities. Track quality variables, such as longitudinal level, were measured effects 1250 m section Swedish Iron Ore Line in autumn 2022. provided frequent measurements...

Engineering process control and high-dimensional, time-dependent data present great methodological challenges when applying statistical (SPC) design of experiments (DoE) in continuous industrial processes. Process simulators with an ability to mimic these are instrumental research education. This article focuses on the revised Tennessee Eastman simulator providing guidelines for its use as a testbed SPC DoE methods. We provide flowcharts that can support new users get started Simulink/Matlab...

Abstract Timely planning and scheduling of railway infrastructure maintenance interventions are crucial for increased safety, improved availability, reduced cost. We propose a data‐driven decision‐support framework integrating track condition predictions with tactical operational scheduling. The acknowledges prediction uncertainties by using Wiener process‐based model at the level. also develop algorithms One algorithm focuses on cost‐optimisation, one considers multi‐component...

Purpose – The purpose of this paper is to summarize previously reported benefits, drawbacks and important aspects for implementation performance-based logistics (PBL), identify knowledge gaps. Design/methodology/approach This a literature review based on 101 articles. reviewed articles are relevant PBL in particular, but also performance contracting, product-service systems (PSS) servitization general. research method involved database searches, filtering results reviewing publications....

Abstract Process monitoring by use of multivariate projection methods has received increasing attention as it can reduce the problem for richly instrumented industrial processes with many correlated variables. This article discusses and control a continuously operating experimental blast furnace (EBF). A case study outlines need EBF principal components (PCs) to monitor thermal state process. The addresses design, testing online application PC models process monitoring. results show how be...

ABSTRACT This article proposes a Bayesian procedure to calculate posterior probabilities of active effects for unreplicated two-level factorials. The results from literature survey are used specify individual prior the activity and then calculated in three-step where principles sparsity, hierarchy, heredity successively considered. We illustrate our approach by reanalyzing experiments found literature.

ABSTRACT Discontinuous processes dominate experimental applications in practice as well literature. Continuous constitute a significant part of goods production, and the need to gain knowledge using experiments are relevant such environments in, for example, parts production. We argue that characteristics continuous affect prerequisites efforts an extent they special attention. To describe considerations when planning process, performed blast furnace process studied. propose tentative list...

Purpose – The purpose of the paper is to explore application radio frequency identification (RFID) improve traceability in a flow granular products and illustrate examples special issues that need be considered when using RFID technique process industry setting.

ABSTRACT Process dynamics is an important consideration during the planning phase of designed experiments in dynamic processes. After changes experimental factors, processes undergo a transition time before reaching new steady state. To minimize and reduce costs for design analysis, knowledge about this important. In article, we propose method to analyze process estimate by combining principal component analysis transfer function–noise modeling or intervention analysis. We illustrate...

Dynamic processes exhibit a time delay between the disturbances and resulting process response. Therefore, one has to acknowledge dynamics, such as transition times, when planning analyzing experiments in dynamic processes. In this article, we explore, discuss, compare different methods estimate location effects for two‐level factorial where responses are represented by series. Particularly, outline use of intervention‐noise modeling method using averages response observations each run...

Researchers have promoted statistical improvement methods as essential for product and process decades. However, studies show that their use has been moderate at best. This study aims to assess the of control (SPC), capability analysis, design experiments (DoE) over time. The also highlights important barriers wider these in Sweden a follow-up similar Swedish performed 2005 two Basque-based 2009 2010. While survey includes open-ended questions, results are mainly descriptive confirm previous...

The active radio frequency identification (RFID) technique is used for in-situ measurement of acceleration and temperature in the distribution chain iron ore pellets. results this paper are based on two experiments, which RFID transponders were released into train wagons or product bins. exciters readers installed downstream a harbour storage silo to retrieve data from transponders. Acceleration peaks temperatures recorded. imply that can aid understanding induced stresses along to, example,...

Abstract This article discusses the design and analysis of an experiment performed in a continuous process (CP). Three types iron ore pellets are tested on two levels variable experimental blast furnace process, using full factorial with replicates. A multivariate approach to form principal component combined variance is proposed. The method also considers split‐plot‐like structure experiment. exemplifies how can be used perform product development experiments CP. CPs demand special...

Industrial manufacturing processes often operate under closed‐loop control, where automation aims to keep important process variables at their set‐points. In industries such as pulp, paper, chemical and steel plants, it is hard find production operating in open loop. Instead, control systems will actively attempt minimize the impact of disturbances. However, we argue that an implicit assumption most experimental investigations studied system loop, allowing factors freely affect responses....

Abstract The concurrent use of statistical process control and engineering involves monitoring manipulated controlled variables. One multivariate chart may handle the all variables, but observing variables in separate charts improve understanding how disturbances controller performance affect process. In this article, we illustrate step ramp manifest themselves a single‐input–single‐output system by studying their resulting signatures is variations widely used...

Abstract This article illustrates a Six Sigma project aimed at reducing manufacturing‐induced visual deviations for fibre‐reinforced polymer (FRP) composites. For European composites manufacturer, such lead to scrapping of cylindrical composite bodies and subsequent environmental impact. The are manufactured through vacuum infusion, where resin mixture impregnates fibreglass preform cures, transforming from liquid solid state. We illustrate the define‐measure‐analyse‐improve‐control (DMAIC)...