R.M. Chandima Ratnayake

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• PhD Offshore Engineering
• Professor (Full) at University of Stavanger

Abstract The implementation of digital Value Stream Mapping (VSM) can enhance the efficiency of business processes (BPs) in engineering knowledge work by identifying and eliminating waste, with a positive impact on sustainability. The study utilizes a combination of action research and case study methodology. It begins with an extensive literature...

This study focuses on plastic waste and the need for a circular economy approach to reduce its exploitation. The aim of the study is to explore alternative future scenarios for implementing a circular business ecosystem for plastic products or waste. The research uses scenario planning to address the uncertainty surrounding sustainability aspects....

Purpose: Addressing sustainability challenges in additive manufacturing (AM) is critical due to high energy consumption and waste. Optimising AM operations is vital for sustainability. However, the existing literature lacks practical examples for AM companies on how to enhance sustainability. To address this gap, a case study within an AM firm was...

The emergence of the circular economy (CE) paradigm is a key driver in steering industrial sectors towards sustainability. The formulation of a robust circularity strategy depends on a comprehensive assessment, which is closely related to the overarching goal of managing the transition to circularity. The initial phase of transition within the heal...

Purpose The purpose of this study is to explore the integration of risk management and circular economy (CE) principles within the healthcare sector to promote sustainability and resilience. Specifically, the study aims to demonstrate how risk management can support the transition to a circular economy in healthcare supply chains. By integrating ri...

Water, a fundamental and indispensable resource necessary for the survival of living beings, has become a pressing issue in numerous regions worldwide due to scarcity. Urban areas, where the majority of the global population resides, witness a substantial consumption of blue water, particularly in commercial buildings. This study investigates the p...

Elevator systems serve as the primary mode of transportation in tall buildings which consumes approximately 5–15% of a building's total energy demand. This research explores the potential for energy savings in elevator systems while maintaining passenger comfort through the implementation of green approaches. The research concentrates on a contempo...

Purpose This study explores digital transformation in the tea supply chain within developing economies, with a focus on smallholder tea producers in Sri Lanka. Tea is one of the most widely consumed beverages in the world. Among the tea producers, smallholder tea producers account for a substantial portion of total tea production in several countri...

Purpose The purpose of this study is to investigate the integrated application of business process modeling and notation (BPMN) and value stream mapping (VSM) to improve knowledge work performance and productivity in police services. In order to explore the application of the hybrid BPMN-VSM approach in police services, this study uses the departme...

The fresh vegetable supply chain (FVSC) is a vital food supply chain for human consumption patterns. There are several hindering issues in the FVSC. Specifically, issues related to logistics operations are directly affecting the socio-economic statuses of the value chain actors and the vegetable ecosystem. Therefore, this research study reviewed th...

High-quality healthcare prevents disease and improves the quality of life by utilizing doctors, nurses, drugs, medical support, and other services. The primary goal of the healthcare supply chain is to deliver products on time to satisfy the needs of healthcare service providers. Due to numerous relevant barriers, it is challenging for the health s...

Waste is a main issue in vegetable supply chains. Many studies focus on food loss in the context of waste, however, neglecting the losses due to farm inputs, handling & inter-relational inefficiencies, and suboptimal resource (labour, time, etc.) & energy consumption. This study aims to address the issue of waste in vegetable supply chains by focus...

International fabrication codes and standards provide minimum distance criteria for proximity welds, although rigorous justification is lacking. These distances are either based on practical experience or mutual agreement and are often left to the engineering judgment of contractors, inspection engineers, etc., especially in cases of repair welds f...

Purpose This paper aims to explore knowledge work waste and defines the priorities for enhancing performance and productivity in policing and prosecution services (PPS), especially in the crime investigation process (CIP). Design/methodology/approach Using the analytic hierarchy process (AHP), a case study of a Norwegian police district is examine...

There is a rising regulatory and societal concern for the environment, forcing companies to include the circular economy (CE) concept in their business models and management practices. The transition towards a CE is inescapable and requires engineering to order (ETO) organisations to re-think their strategy and the way they create and deliver value...

Digital transformation has taken place in many industrial sectors to gain leverage by the technology implementation or to transform the whole organization or its parts. The digital transformation has grown to become popular, especially in agriculture supply chains related research. Research journals have reported more digital technology application...

The healthcare supply chain is significantly unsustainable due to the linear resource consumption. Implementing circular economy (CE) principles in the health sector supply chains are in an evolution phase. Manufacturers and service providers need to strengthen the integration for enhancing healthcare supply chains to minimize linear resource consu...

A Lean approach is frequently applied in the internal processual settings of many companies but is less common in the after-delivery service context, which is dominated by office and knowledge work. The multi-supplier retail (MSR) industry may benefit from a Lean digital approach to utilize effectively business-critical data from the after-delivery...

Purpose This paper aims to propose a methodology to support public managers' adaptation of the Hoshin Kanri (HK) strategy deployment approach in the context of lean thinking (LT), considering strategic alignment and consensus reaching when prioritizing a vital few of the organization's continuous improvement (CI) projects. Design/methodology/appro...

Digitalization of the failure-probability modeling of crucial components in power-distribution systems is important for improving risk and reliability analysis for system-maintenance and asset-management practices. This paper aims to implement a Python programming-based Weibull approach for digitalization of distribution-transformer (DT) failures,...

Circular economy (CE) targets provide an economic model to focus on the efficient use of resources by minimization of the waste, reduction of the linear consumption of natural resources, long-term value creation, and making material consumption circular. The building and construction sector is responsible for significantly increasing the carbon foo...

Recent advances in additive manufacturing (AM) technology provide the potential for on-demand and rapid production of spare parts during urgent repair times. Recently, big oil and gas companies have shown early progress in using additive technology in manufacturing specific heat exchangers, downhole cleanout tool nozzles, offshore risers, gas turbi...

Nickel-based alloys are used for a broad range of applications in oil and gas (O&G) production and marine engineering because of their good corrosion resistance and mechanical properties. The future of laser AM in the O&G industries is highly promising due to the ability to deliver cheaper and better parts quickly. As it is in the initial stages, r...

Pipelines are the most common and economical way of transporting hazardous liquid hydrocarbons. Steel pipelines suffer different degradation mechanisms due, in part, to corrosion reactions. Failure in a hazardous liquid pipeline can result in catastrophic environmental damage as well as societal health and safety threats. There are many standard me...

Didactic guide for utilization of digital manufacturing tools for product development and manufacturing (ProDeM) in higher education

High carbon, high chromium tool steels are deep hardening steels widely used for cold forming dies. A 400 W Nd:YAG laser was employed to melt the surface of the AISI D2 tool steel with 5 and 6 ms single pulses of laser at 4–10 J energy levels. The microstructural study showed that complete dissolution of large primary carbides occurred during melti...

Maintaining minimum distance between repair and existing welds often becomes impractical due to the presence of compact layouts, original welds of branches, nozzles, etc. on offshore structural elements, pipelines, and piping. Although some international codes and standards provide criteria for maintaining a minimum distance between proximity welds...

Steel plates with openings are among the important ship structural components used in the ship’s hull to withstand the hydrostatic forces of the ocean, which cause sagging and hogging moments at the ship’s bottom. The existence of openings on plates can cause structural rupture, stress concentration and a decrease in ultimate strength. This researc...

Maintaining the minimum allowable distance between proximity welds has always been considered a subject of debate among design engineers, welding engineers/inspectors and fabricators/engineering contractors. The scattered nature of guidelines available in welding codes and standards for maintaining the minimum allowable distance poses a significant...

Noise pollution associated with wind turbines results in a significant level of environmental and societal impact. The effect of noise pollution intensity on residential locations varies depending on the surrounding activities. Therefore, wind power generation asset owners should consider the surrounding environment before setting up the wind farm...

Welding residual stress (WRS) estimation is highly nonlinear process due to its association with high thermal gradients generated during welding. Accurate and fast estimation of welding induced residual stresses in critical weld geometries of offshore structures, piping components etc., becomes important from structural integrity perspective. Fitne...

In this study the effect of laser surface melting (LSM) on the amount of retained austenite, hardness and wear resistance of AISI D2 steel was investigated utilizing hardness test, X-ray diffraction (XRD), pin on disk wear test and scanning electron microscopy (SEM). In order to evaluate wear resistance, pin on disk tests at two different loads wer...

Thin-walled cylindrical shell storage tanks are pressure vessels in which the walls of the vessel have a thickness that is much smaller than the overall size of the vessel. These types of structures have global applications in various industries, including oil refineries and petrochemical plants. However, these storage tanks are vulnerable to fire...

Maintaining minimum allowable distance between proximity welds has always been considered a subject of debate between design engineers, welding engineers/inspectors and fabricators/engineering contractors. The scattered nature of guidelines available in welding codes and standards for maintain minimum allowable distance pose a significant challenge...

Welding residual stress (WRS) estimation is highly nonlinear process due to its association with high thermal gradients generated during welding. Accurate and fast estimation of welding induced residual stresses in critical weld geometries of offshore structures, piping components etc., becomes important from structural integrity perspective. Fitne...

The public services’ related strategy deployment (SD) process involves complex and multi-criteria decision-making. Group decision-making is often characterized by, among other things, some degree of managerial discretion, silo thinking, poor consensus and ad hoc approaches, for simplification purposes. This reduces consistency and results in a high...

The purpose of this manuscript is to propose a framework for implementing 5S+S in engineering-to-order (ETO) projects with a focus on knowledge work. The application of this framework helps to improve overall performance in companies providing knowledge work. The methodology allows transparency and control over projects in day-to-day management, th...

Lean Six Sigma (LSS) continues to greatly interest public sector organizations as a means to continuously improve service performance. However, given the plethora of research and literature on LSS in the public sector, research specifically about LSS in policing and prosecution services, which are dominated by knowledge work, is significantly limit...

This paper presents a tailor-made value stream mapping (VSM) methodology for engineering projects with a focus on knowledge work. The VSM is a lean-management method for analyzing value-adding processes through material and information flow mapping. The tool helps organizations to reduce engineering hours, lower project costs and improve project ma...

Friction stir spot welding (FSSW) is a solid-state joining technique which is used to weld alloys that has a low weldability such as the 2000 and 7000 series aluminum alloy. The marine, automotive and aerospace industry benefits using this method as the need for weight reduction and fuel economy make the use of aluminum and other light metals neces...

Welding is a highly nonlinear temperature distribution process, where the presence of high-temperature gradients leads to the development of significantly high residual stress levels, up to and/or beyond the material yield strength magnitude and localized plastic deformation. To achieve the desired dimensional accuracy, determination of plastic zon...

Residual stress estimation in structural integrity procedures plays an important role during the fitness-for-service (FFS) assessment of girth welds. Various FFS codes and standards, such as API 579 and BS 7910, recommend predetermined residual stress profiles based on finite element modeling (FEM) coupled with experimental results. Nonlinearity as...

Despite being considered the safest means to transport oil and gas, pipelines are susceptible to degradation. Pipeline integrity management (PIM) is implemented to lower the risk of failure due to degradation and to maintain the functionality and safety of pipelines. PIM consists of a set of activities for assessing the operational conditions of pi...

Purpose The purpose of this paper is to present a risk-based prioritization method (RBPM), using functional failure risk and strategic importance assessment, in order to support public managers' decision-making process for the planning and allocation of scarce resources. Design/methodology/approach The methodology incorporates two assessment matri...

The majority of hydrocarbon reservoirs discovered in recent years contain considerable corrosive hydrogen sulfide. The pipeline material for this application needs to be resistant to hydrogen-induced defects. API 5L PSL2 X60MS is one of the most common material grades for use in sour service applications. However, due to the complexity of affecting...

This manuscript proposes a statistical experimentation approach for investigating the combination of parameters that provides an optimal friction stir welded joint for the AA6082-T6 aluminum alloy. The statistical experimen-tation was carried out using a Mazak VCN-430a vertical milling machine. Plates with a uniform thickness of 3 mm were welded in...

This manuscript presents the results from an experimental investigation performed to study the material and mechanical properties of two weld joints manufactured within close proximity. The experiment has been designed using seven welded S420G2 + M 500 × 300 × 15 mm structural steel plates, with varying distances between two parallel adjacent weld...

There is a lack of quantitative data regarding the determination of minimum distances between weld joints in offshore structures. Existing welding standards, codes and specifications provide recommendations for minimum distances between two adjacent weld joints. The issue arises when violations of the minimum recommendations are discovered in the f...

There is insufficient information available in existing welding standards, codes and specifications regarding the implications of having two or several adjacently fabricated weld joints in close proximity. This has introduced fatigue life performance uncertainties, due to a lack of understanding of the inherent behaviour of weld joints in the prese...

The need for enhancing Risk-Based Inspection (RBI) strategies has received significant attraction of many researchers and practitioners in the offshore/onshore oil and gas. Qualitative RBI (QRBI) has many applications in risk assessment of the aging assets, screening of the asset based on their risk level, and also in full risk assessment analysis...

In typical fabricated structures, there are hundreds of joints, which acts as a potential location for fatigue cracking. Ageing and life extension (ALE) of such structures could be developed further by creating an optimal measure between the required quality level and fatigue performance defined in quality inspection code of welded joints. The qual...

The distribution of residual stresses in welded joints plays an important role within the fracture evaluation guidelines recommended in structural integrity assessment codes such as BS7910, API 579 RP-1/ASME FFS-1 and R6. The residual stress profile recommendations in these standards are based on extensive experimental results and finite element mo...

The paper concerns the planning of complex technological processes (CTP). Nowadays, CTP are gaining new meaning in manufacturing environments. This is due to the increased number of innovative solutions having a crucial impact on the effectiveness of production. CTP can be defined as manufacturing approaches which are a blend of the traditional and...

The paper presents different techniques for digitizing grinding pins and discusses the use of digitalized pins and the results of measurements in technological process planning (TPP), focusing on the challenges of the digital era. It describes the potential of different measuring devices, taking into account the digitization of a real tool shape in...

Visual inspection forms the basis of the inspection planning process for concrete bridges. The authority responsible for bridge inspection maintains a database to record past inspection results, in order to plan future inspections. It is a challenge to recognize and classify bridges that it is essential to inspect based on inherent requirements. Th...

Optimization of resource utilization plays a significant role in the continuous improvement initiatives of an organization providing services. Lean thinking and systematic approaches, such as multicriteria analysis (MCA), are necessary to optimize the utilization (or allocation) of human resources (HR) in a public service organization, especially t...

Within the field of management, knowledge management (KM) enables the generation, sharing, utilization and management of knowledge and information. In order to optimize the processes of KM, Lean thinking and tools can contribute to identifying and eliminating or reducing waste or activities and/or actions that disrupt or do not add value to the inf...

Digital transformation (DT) is gaining interest and changing citizens’ expectations of service organizations’ ability to deliver high-value, real-time digital services. However, from an organizational perspective, DT entails a continuum of transitions that emphasize cultural, organizational, processual and relational changes. Over the past few deca...

It is a mandatory requirement to maintain offshore oil and gas (O&G) production and process platforms during the engineering down period (i.e. the period from the end of the design/operational life to decommissioning). Decommissioning of the offshore production and process (OP&PPs) involves cessation of operations, withdrawal of the facility from s...

Residual stresses are internal self-equilibrating stresses that remain in the component even after the removal of external load. The aforementioned stress when superimposed by the operating stresses on the offshore piping, enhance the chances of fracture failure of the components. Thus, it is vital to accurately estimate the residual stresses in to...

In offshore structures, pipelines and piping, there are various configurations where welds are often in close proximity to each other. TKY joints in offshore structures, welds of nozzles, tees, elbows and circumferential welds of piping in compact layouts are a few examples. Depending on their application, different codes (ASME B31.3, ISO 19902, et...

Accurate prediction of the fatigue strength of steels is vital, due to the extremely high cost (and time) of fatigue testing and the often fatal consequences of fatigue failures. The work presented in this paper is an extension of the previous paper submitted to OMAE 2019. The main objective of this manuscript is to utilize Artificial Intelligence...

Technology qualification (TQ) has been employed to perform assessments to verify whether a new technology performs within pre-specified functional limits after an application. If a best available technology (BAT) is used in a new environment, it is considered as a new technology. The TQ is vital in the implementation of best available technology (B...

The inspection of reinforced concrete bridges is vital to assure load-bearing capacity, traffic safety (health and societal safety) and aesthetics and the ability to cope with environmental challenges and, as well as to minimize maintenance costs. Bridge inspection accrues significant costs due to lack of cross fertilization with the standard appro...