R. M. Chandima Ratnayake

Technical Integrity Management: Measuring HSE Awareness Using AHP in Selecting a Maintenance Strategy

Purpose – The purpose of this paper is to provide a comprehensive overview of technical integrity management (TIM) and propose a methodology for assessing to which extent the technical integrity (TI) performance is balanced in terms of goal awareness among the personnel responsible for TIM, and the degree to which high level goals are implemented in maintenance strategies.Design/methodology/approach – The study involved a comprehensive literature survey as well as information and data collected in the Norwegian oil and gas (O&G) industry. Several discussion rounds were carried out with the industrial maintenance management experts to recognize the existing practices and to confirm the suggested model.Findings – The literature review indicated that there is a need for a methodology for assessing to which extent the technical integrity (TI) performance is balanced in terms of goal awareness among the personnel responsible for TIM, and the degree to which high‐level goals are implemented in maintenance strat...

Modelling of asset integrity management process: a case study for computing operational integrity preference weights

Operational integrity management of industrial assets is concerned with systematically and completely reviewing, analysing and developing or sustaining the ability of assets’ operations. Breaches of assets’ integrity occur when conflicting interests, such as financial, environmental and societal milieus, are incorrectly weighed against each other. In order to attain sustainable asset performance, it is vital to compute the different weights given to the factors governing operational integrity. In this context, it is vital to realise a correct balance between the conflicting interests of employees and the institutionalised interests derived from sustainable asset operations. This manuscript illustrates a study focusing on operational integrity, which has been carried out in collaboration with a leading gas processing and distribution company located in Norway. Also, the manuscript illustrates how to model asset integrity management processes in general and compute operational integrity preference weights complying with ‘triple bottom line’ using the analytic hierarchy process.

Maintaining Technical Integrity of Petroleum Flowlines on Offshore Installations: A Decision Support System for Inspection Planning

Oil and Gas (O&G) platforms in the North Sea are facing aging problems as many of the installations have matured and are approaching their design lifetime. Flowlines are used to transport oil and gas well stream from the wellhead to the production manifold. They are categorised as one of the most critical components on a production facility. Flowline degradation takes place due to corrosion and erosion. The deterioration of a flowline may increase the risk of leakages, ruptures, etc., which shall lead to serious HSE (health, safety and environmental) and financial consequences. Any such risks have a direct impact on the O&G installation’s technical integrity as well as the operator’s sustainability concerns. Conventionally, pipelines are designed with safety provisions to provide a theoretical minimum failure rate over the life span. Furthermore, to reduce the risk of failure various techniques are routinely used to monitor the status of pipelines during the operation phase. The existing methods of flowline health monitoring planning requires one to take into consideration the operator’s plant strategy, flowline degradation mechanisms, historical data, etc. A technical condition report is made based on findings’ reports and degradation trends. This report recommends the inspection of a number of points on the flowlines in a certain year using non-destructive evaluation methods such as visual inspection, ultrasonic testing, radiographic testing, etc. Based on the technical condition report, in general for a certain preventive maintenance shutdown, 10 to 15 flowline inspection openings are accommodated as finance, time and resource availability are taken into consideration. However, it is customary to plan to open more locations in a certain inspection package than can be inspected and minimization of such points is at present done on an ad hoc basis. This paper suggests a formal model and a framework to formally minimize the number of visual inspections by executing the plant strategy as well as HSE concerns. The model is derived using analytic hierarchy process (AHP) framework, which is a multi-criteria decision-making approach. The model is developed based on literature, industrial practice, experience as well as real inspection data from a mature offshore O&G installation located on the Norwegian Continental Shelf.© 2010 ASME

Challenges in Inspection Planning for Maintenance of Static Mechanical Equipment on Ageing Oil and Gas Production Plants: The State of the Art

Although the design life of many of the oil and gas (O&G) production and process facilities on the Norwegian Continental Shelf (NCS) has been exceeded, the same physical assets are still under exploitation as a result of extended life based on the information gathered by inspection, maintenance, modification and replacement history. Nevertheless, pressure systems, which comprised of static mechanical equipment such as piping components (valves, separators, tanks, vessels, spools, etc.), undergo continuous inherent deterioration (fatigue, corrosion, erosion, etc). Often the deterioration rates vary over the lifetime following no specific pattern due to the changes in product quality of the well stream, varying environmental conditions and unexpected cyclical loading. These necessitate effective inspection planning to repair, modify or replace those components that reach the end of their design life. This enables the integrity of the physical assets to be retained at a tolerable level. The inspection planning has traditionally been driven by prescriptive industry practices and carried out by human experts, based on risk-based inspection (RBI) and risk-based maintenance (RBM) philosophies. The RBI and RBM involve the planning of inspections on the basis of the information obtained from risk analyses of a particular system and related equipment. This manuscript reviews the evolution of inspection and maintenance practices. Then it provides a conceptual framework to mechanize the inspection planning process in order to reduce the effect arising from human involvement, whilst improving the effective utilization of data from different sources.Copyright

Maintenance Integrity: Managing Flange Inspections on Aging Offshore Production Facilities

The flange inspection associated with piping on offshore production facilities is a time-consuming activity as the flanges should physically be opened in order to perform close visual inspections. In order to sustain maintenance integrity, a number of inspections are allocated for a subsystem based on factors such as: condition of the medium flowing in the line, risk perception of the pipeline system, and the date of installation. Inspection teams recommend inspections based on the data, experience, and exposure to offshore production facilities, as well as the intuition and intentions of those individuals involved with inspection planning and with carrying out implementation during the preventive maintenance shutdowns. However, there is a tendency for the operating company representatives to raise queries with the contractor company representatives about the number of flanges to be opened during the preventive maintenance shutdown as flange inspection consumes a considerable portion of time and resources. Hence, it is vital to interpret sensibly the importance of recommending close visual inspections for flanges if the maintenance integrity is to be sustained. This study focuses on analyzing the historical data limited to flanges on flowlines over the last fifteen years. The final results provide a snapshot of the present status of the flanges of the production facility.Copyright

Simple approach for Value Stream Mapping for business process analysis

In order to achieve fast deliveries via short lead times, companies have to look for different manufacturing possibilities. Inherently, Value Stream Mapping (VSM) aids in identifying waste in manufacturing processes as well as related business processes focusing on minimizing possible time wastages. There is a trade-off between costs vs. shorter manufacturing or overall lead time. The main challenge is the elimination of waste to shorten overall manufacturing or business process (BP) time and related costs. The VSM has been conventionally utilized for manufacturing process analysis. It is typically observed that personnel in industrial organizations trying to optimize the overall price and lead time focus only on manufacturing related waste reduction. There are significant wastages generated from overall BP, which also directly or indirectly influence lead time to move beyond the anticipated threshold limits. Hence, this manuscript puts effort into developing a simple approach for VSM for analyzing and investigating drawbacks in the overall BP. A case study has been performed in collaboration with an aircraft-spare-parts manufacturing firm (AMF). A simple approach has been developed using the case study to investigate the inefficiencies present in the quotation preparation process (QPP). In addition to the approach, the resulting current state map (CSM), future state map (FSM), lead time (LT), processing time (Tp), process cycle efficiency (PCE), value added activity improvement (VAI) and non-value added activity improvement (NVAI) have all been analyzed.

In-service inspection of static mechanical equipment: Use of a fuzzy inference system for maintaining the quality of an inspection program

It is necessary to inspect the piping components of offshore production and process facilities (OP&PFs) to investigate potential failures. This is especially vital for aging OP&PFs in order to make the necessary engineering judgments regarding maintenance and modification (M&M) activities. In an OP&PF, piping plays a vital role within the static mechanical equipment. To analyze the degradation trends in the piping, the wall thickness measurements have been periodically monitored and recorded at the locations with a high risk of failure. Inspection planners make recommendations on the thickness measurement locations (TMLs) to be monitored based on: the currently available recorded data, risk-based inspection (RBI) analysis results, plant inspection strategy guidance and other regulatory requirements. The quality of the recommendations made by an inspection planner to prioritize TMLs depends on their experience and competence. Hence, it is vital to develop expert systems to support and minimize sub-optimal decisions when an inspection planner is inexperienced. This manuscript illustrates the use of a fuzzy inference system (FIS) for making optimal in-service inspection recommendations based on the current status and trends of TMLs in the static mechanical equipment of an OP&PF. The proposed FIS enables the expertise of experienced inspection planners to be incorporated via developed membership functions (MFs) and a rule base, which will support and maintain the quality of an inspection program at the intended level.

Industrial Asset Maintenance and Sustainability Performance: Economical, Environmental, and Societal Implications

Sustainability performance appears to be one of the most influential concepts for managing modern businesses. Over the last few years it has drawn significant attention from many socio-political and socio-economical sources as the serious challenges encountered by both western and eastern societies were subjected to discussions and debates. This concept by far questions and challenges the fundamentals of commercial activities and its complex interactions with the environment external to an organization.

Fatigue and Fracture Degradation Inspection of Offshore Structures and Mechanical Items: The State of the Art

A significant number of offshore structures and mechanical items installed in production systems on the Norwegian Continental Shelf (NCS) are either approaching or have exceeded their intended design life. However, with the help of the advancement of technology and analysis approaches, most of the offshore production facilities are being considered for life extension. This requires regular inspection, fitness for service (FFS) assessment, remnant life assessment, maintenance and repair (or modification). In this context, fatigue and fracture related degradation play a vital role. Hence, this paper discusses the state of the art as well as two major methodologies used for fatigue life prediction of structures and mechanical items. The first (S-N approach) is based on experimentally derived S-N curves and linear damage rule (LDR). Since LDR does not take sequence effect of loading into account the S-N approach often leads to overestimation / underestimation of fatigue life. Hence, this paper also takes into simultaneous consideration the second approach, which relies on the principles of fracture mechanics (FM) and crack growth analysis. Furthermore, the paper discusses damage tolerance analysis (DTA) and the role of Risk Based Inspection (RBI) to detect cracks before they grow to a critical level and cause catastrophic failure of the component. Thereafter, the paper discusses the reliability of Non-Destructive Evaluation (NDE) methods quantified in terms of Probability of Detection (PoD), to identify the flaw size and location. Finally, probabilistic crack growth (PCG) models used for remaining useful life estimation (RULE) and for planning inspection regimes of structural and mechanical items are discussed briefly.Copyright

Development of a rule base and algorithm for a quotation preparation process: A case study with a VSM approach

Quotation preparation lead time plays a significant role in the aircraft components manufacturing (ACM) industry. This is especially due to the fact that on each occasion the sub-contracting suppliers have to manufacture component(s) of which they have no previous experience based on the external demand. The quotation preparation takes place between different actors once the request for a manufacturing proposal has been met. Also, a particular ACM organization investigates the potential capabilities of the selected sub-contracting manufacturers and their suppliers. The sub-contracting manufacturers have to select sub-suppliers to purchase necessary semi-finished goods and raw material to meet the anticipated quality requirements posed by the ACM organization. The waste in terms of time is significantly high due to the possible delays in data and information flow during the quotation preparation process (QPP). The time wastages are mainly caused by the delays within the same manufacturing organization between different functional units (i.e. internal time wastages) as well as between suppliers and the client (i.e. external time wastages). This manuscript suggests an approach with the help of tailor-made value stream mapping (VSM) to investigate the challenges and mitigate the delays caused during the QPP.