A priori error analysis of discrete-ordinate weak Galerkin method for radiative transfer equation

This research article discusses a numerical solution of the radiative transfer equation based on the weak Galerkin finite element method. We discretize the angular variable by means of the discrete-ordinate method. Then the resulting semi-discrete hyperbolic system is approximated using the weak Galerkin method. The stability result for the proposed numerical method is devised. A \emph{priori} error analysis is established under the suitable norm. In order to examine the theoretical results, numerical experiments are carried out

Winning customer loyalty in an automotive company through Six Sigma: a case study

Six Sigma is a disciplined approach to improving product, process and service quality. Since its inception at Motorola in the mid 1980s Six Sigma has evolved significantly and continues to expand to improve process performance, enhance business profitability and increase customer satisfaction. This paper presents an extensive literature review based on the experiences of both academics and practitioners on Six Sigma, followed by the application of the Define, Measure, Analyse, Improve, Control (DMAIC) problem-solving methodology to identify the parameters causing casting defects and to control these parameters. The results of the study are based on the application of tools and techniques in the DMAIC methodology, i.e. Pareto Analysis, Measurement System Analysis, Regression Analysis and Design of Experiment. The results of the study show that the application of the Six Sigma methodology reduced casting defects and increased the process capability of the process from 0.49 to 1.28. The application of DMAIC has resulted in a significant financial impact (over U.S. $110 000 per annum) on the bottom-line of the company

Enterprise-wide diagnostic in the UK SME: focus beyond tools and techniques

The paper proposes a theoretical framework that integrates the harder aspects of enterprise-wide diagnostic methodology, i.e. tools and techniques, with softer issues to understand and analyse enterprise-wide issues in the UK manufacturing SME. Enterprise-wide diagnostics application that considers hard and soft practices for managing change in a SME context is less evident in the literature and practice. Case study was conducted in the selected SME and data triangulation was achieved through on-site observations, interviews, and company reports. The use of integrated framework, influenced by Watson (1994), led to identification of several gaps between the three levels- enterprise, business, and operations, that were impacting on demand management and capacity planning. The paper demonstrates the benefits of conducting enterprise-wide diagnostic as a first step to enhance better integration between organisational levels and departments when embarking on continuous improvement journey

Synergies and misalignments in lean and green practices: a logistics industry perspective

This paper conducts an exploratory case study-based research in three companies to identify the main synergies and misalignments between Lean and Green in the context of a range of distribution networks operating globally, regionally and domestically. The research strategy applied by this study is exploratory multiple case studies in three companies, particularly in the road transport and logistics sector. Semi-structured interviews with fifteen executives from three companies were conducted to identify activities within logistics operations leading to synergies and misalignment between Lean and Green practices. The outcome of the three cases shows that several improvements can be achieved by the simultaneous adoption of Lean and Green. The study contributes to the literature by extending the research in the logistics sector and providing examples from a wide variety of logistics operations on synergies and misalignments between Lean and Green practices. The findings and outcome of this study are a starting point for further research in the logistics sector

Analysis of an implicitly extended Crank-Nicolson scheme for the heat equation on a time-dependent domain

We consider a time-stepping scheme of Crank-Nicolson type for the heat equation on a moving domain in Eulerian coordinates. As the spatial domain varies between subsequent time steps, an extension of the solution from the previous time step is required. Following Lehrenfeld \& Olskanskii [ESAIM: M2AN, 53(2):\,585-614, 2019], we apply an implicit extension based on so-called ghost-penalty terms. For spatial discretisation, a cut finite element method is used. We derive a complete a priori error analysis in space and time, which shows in particular second-order convergence in time under a parabolic CFL condition. Finally, we present numerical results in two and three space dimensions that confirm the analytical estimates, even for much larger time steps

A decision theory perspective on complexity in performance measurement and management

Purpose – The purpose of this paper is to apply the aspects of decision theory to performance measurement and management (PMM), thereby enabling the theoretical elaboration of volatility, uncertainty, complexity and ambiguity in the business environment, which are identified as the barriers to effective PMM. Design/methodology/approach – A review of decision theory and PMM literature establishes the Cynefin framework as the basis for extending the performance alignment matrix. Case research with seven companies explores the relationship between two concepts underexamined in the performance alignment matrix – internal dominant logic (DL) as the attribute of organisational culture affecting decision making, and the external environment – in line with the concept of alignment or fit in PMM. A focus area is PMM related to sustainable operations and supply chain management. Findings – Alignment between DL, external environment and PMM is found, as are instances of misalignment. The Cynefin framework offers a deeper theoretical explanation about the nature of this alignment. Other findings consider the nature of organisational ownership on DL. Research limitations/implications – The cases are exploratory not exhaustive, and limited in number. Organisations showing contested logic were excluded. Practical implications – Some organisations have cultures of predictability and control; others have cultures that recognise their external environment as fundamentally unpredictable, and hence there is a need for responsive, decentralised PMM. Some have sought to change their culture and PMM. Being attentive to how cultural logic affects decision making can help reduce the misalignment in PMM. Originality/value – A novel contribution is made by applying decision theory to PMM, extending the theoretical depth of the subject

Creating highly reliable health care organisations through reverse exchanges

Purpose This paper aims to explore patient to care provider reverse exchanges to improve the care processes and service supply chain using an online feedback platform. This paper demonstrates how a better understanding of timely and unsolicited feedback (“voice of the patient as a customer”) stimulates local interventions to improve service delivery and enact the essential characteristics of highly reliable organisations (HRO). Design/methodology/approach A realist approach involving an exploratory hospital case study using user feedback from an IT patient feedback platform. The methodology included interviews, secondary data and access to thousands of patient feedback narratives. Findings The findings show that a systems approach to the supply chain, using real-time feedback to enact process improvement is beneficial and a fruitful source of innovation for professional services staff. The setting of the improvement focusses on a true “voice of the customer” rather than attempting to improve arbitrarily internal process efficiency has major benefits for staff and their engagement with the right interventions to support higher performance. Practical implications The findings show major positive benefits for the adaptation and constant reflection of staff on the service provided to patients. The approach provides a means of reflecting as to whether the current supply chain and service provision are fit for purpose, as well as reliable, efficient and of value to the consumer. Originality/value This study is one of a few that adopt the consumer orientation needed to fully exploit the concepts of patient-centric improvement by including dynamic feedback in the supply chain and systems approach to care

Condition monitoring for airport baggage handling in the area of industry 4.0

Purpose: The findings of a recent study are presented, which was conducted with the objective of addressing the problem of the failure of baggage carts within the high-speed baggage tunnel at Heathrow Terminal 5 through the development of an innovative condition-based maintenance system designed to meet the requirements of 21st century airport systems and Industry 4.0. Methodology: An empirical experimental approach to this action research was taken to install a vibration condition monitoring pilot test in the north tunnel at Terminal 5. Vibration data were collected over a 6-month period and analysed to determine the threshold for good quality tyres and those with worn bearings that needed replacing. The results were compared with existing measures to demonstrate that vibration monitoring could be used as a predictive model for condition-based maintenance. Findings: The findings demonstrated a clear trend of increasing vibration velocity with age, with the wheel mass unbalanced inertia of the carts being transmitted to the tracks as vibration. This research demonstrates that a healthy wheel produces a vibration of less than 60mm/s whereas a damaged wheel measures up to 100 mm/s peak to peak velocity, which can be used in real-time condition monitoring to prevent baggage cart failure. It can also run as an autonomous system linked to AI and Industry 4.0 airport logic. Originality/Value: Whilst vibration monitoring has been used to measure movement in static structures, such as bridges, and in rotating machinery, such as railway wheels (Tondon and Choudhury, 1999) this application is unique as it is the first time vibration monitoring has been applied to a stationary structure (tracks) carrying high-speed rotating machinery (baggage cart wheels). This technique has been patented and proven in the pilot study and is in the process of being rolled out across all Heathrow terminal connection tunnels. It has implications for all other airports world-wide, and also to other applications that rely on moving conveyor belts

Implementing the Lean Sigma Framework in an Indian SME: a case study

Lean and Six Sigma are two widely acknowledged business process improvement strategies available to organisations today for achieving dramatic results in cost, quality and time by focusing on process performance. Lately, Lean and Six Sigma practitioners are integrating the two strategies into a more powerful and effective hybrid, addressing many of the weaknesses and retaining most of the strengths of each strategy. Lean Sigma combines the variability reduction tools and techniques from Six Sigma with the waste and non-value added elimination tools and techniques from Lean Manufacturing, to generate savings to the bottom-line of an organisation. This paper proposes a Lean Sigma framework to reduce the defect occurring in the final product (automobile accessories) manufactured by a die-casting process. The proposed framework integrates Lean tools (current state map, 5S System, and Total Productive Maintenance (TPM)) within Six Sigma DMAIC methodology to enhance the bottom-line results and win customer loyalty. Implementation of the proposed framework shows dramatic improvement in the key metrics (defect per unit (DPU), process capability index, mean and standard deviation of casting density, yield, and overall equipment effectiveness (OEE)) and a substantial financial savings is generated by the organisation