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Article

Subhash Mathew

The purpose of this paper is to model an inspection maintenance strategy that is superior to existing strategies and which incorporates the inspection factor.

Abstract

Purpose

The purpose of this paper is to model an inspection maintenance strategy that is superior to existing strategies and which incorporates the inspection factor.

Design/methodology/approach

An appropriate inspection maintenance strategy can help prevent breakdown failure and reduce breakdown and repair costs. However, every inspection also incurs costs. The optimal model for an inspection maintenance strategy would be such that the inspection frequency closely follows the hazard rate of the equipment over its lifetime.

Findings

A model with a three‐layered structure needs to be developed. Over time, equipment can be expected to demonstrate a hazard rate that is decreasing, constant or increasing with time. In the first stage a model for inspection frequency is developed that is time‐dependent and can address this requirement. Second, the hazard rate has a dynamic relationship with the inspection frequency, i.e. as the inspection frequency increases, the hazard rate is known to decrease. In the second stage this is incorporated into the model, using the inspection factor. In the last stage a model for costing is superimposed for cost optimization.

Originality/value

The model developed in this paper provides maintenance managers with a powerful practical tool for determining the optimal inspection frequency for equipment over its lifetime.

Details

International Journal of Quality & Reliability Management, vol. 25 no. 5
Type: Research Article
ISSN: 0265-671X

Keywords

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Article

R.M. Chandima Ratnayake

The purpose of this paper is to review the evolution of inspection and maintenance (I&M) practices used for aging and newly built oil and gas (O&G) facilities. It also…

Abstract

Purpose

The purpose of this paper is to review the evolution of inspection and maintenance (I&M) practices used for aging and newly built oil and gas (O&G) facilities. It also proposes a framework and an approach for mechanizing inspection planning to perform preventive maintenance (PM) activities, taking technical condition (TC) and relative degradation (RD) into consideration.

Design/methodology/approach

The paper systematically collects, categorizes, and analyzes the published literature of both researchers and practitioners. It also utilizes industrial experience that has been accrued and utilized from inspection planning practices for static mechanical equipment on aging O&G production plants.

Findings

The paper defines significant issues in I&M of O&G assets related to: different philosophies; stakeholders’ requirements trade-off; dependability and asset deterioration challenges; items interacting with inspection planning mechanization processes and I&M optimization approaches. A framework is identified to mechanize the inspection planning process in order to reduce the effect arising from human involvement, while improving the effective utilization of data from different sources. The suggested approach improves the quality of an inspection program, while minimizing the variability and cost to the engineering contractors as well as to the owners of O&G facilities.

Practical implications

The mechanization of inspection planning (MIP) is vital to have inspection programs with uniform quality. The currently employed inspection practices face challenges in maintaining uniform quality from one inspection program to another due to the variability present in the planning process, especially among the different inspection planning engineers. The suggested fuzzy logic-based MIP supports the minimization of the variability and increases the quality of inspection programs.

Originality/value

The paper provides a comprehensive review of research contributions and industrial development efforts. These will be useful to the life cycle stakeholders in both academia and industry in understanding the inspection planning problem and solution space within the O&G asset I&M context.

Details

Journal of Quality in Maintenance Engineering, vol. 21 no. 2
Type: Research Article
ISSN: 1355-2511

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Article

Abdul Hameed, Syed Asif Raza, Qadeer Ahmed, Faisal Khan and Salim Ahmed

The purpose of this paper is to develop a decision support tool for risk-based maintenance scheduling for a large heavily equipped gas sweetening unit in a Liquefied…

Abstract

Purpose

The purpose of this paper is to develop a decision support tool for risk-based maintenance scheduling for a large heavily equipped gas sweetening unit in a Liquefied Natural Gas (LNG) plant. Two conflicting objectives, i.e., total maintenance cost and the reliability, are considered in the tool. The tool is tested with the real plant data and suggests several Pareto-optimal schedules for a decision maker to choose from. The financial impacts are assessed.

Design/methodology/approach

A bi-objective scheduling optimization model is developed for maintenance scheduling using a risk-based framework. The model is developed integrating genetic algorithm and simulation-based optimization to find Pareto-optimal schedules. The model delivered true Pareto front optimal solutions for given plant-specific data. The two conflicting objectives: the minimization of total expenditures incurred on maintenance-related activities and improving the total reliability are considered.

Findings

For large and complex processing facilities such as LNG plant, a shutdown of facility generates a significant financial impact, resulting in millions of dollars in production loss. The developed risk-based equipment selection strategy helps to minimize such an event of production loss by generating a thorough maintenance strategy for inspection, repair, overhaul or replacement schedule of the unit without initiating the shutdown. The proposed model has been successfully applied to obtain an optimize maintenance schedule for a gas sweetening unit.

Research limitations/implications

A future work may consider the state-dependent models for various failure modes that will result in obtaining a better representation of the model. The proposed scheduling can further be extended to multi-criteria scheduling including availability, resource limitation and inflationary condition. A comparative analysis with other meta-heuristic techniques such as harmony search algorithm, tabu search, and simulated annealing will further help in confirming the schedule obtained from this application.

Practical implications

Maintenance scheduling using a conventional approach for special equipment generally does not consider the conflicting objectives. This research addresses this aspect using a bi-objective model. The usefulness of risk-based method is to assist in minimizing the financial and safety risk exposure to the operating companies, but some variation in results is expected due to varying risk matrix for different organizations.

Social implications

Managing two objectives, i.e., minimizing the cost of maintenance-related activities, while at the same time maximizing the overall reliability dramatically, helps in mitigating adverse safety and financial risk due to fires, explosions, fatality and excessive maintenance cost.

Originality/value

Research develops a decision support tool for managing conflicting objectives for an LNG process. This research highlights the impact of utilizing the simulation-based approach coupled with risk-based equipment selection for complex processing unit or plant maintenance scheduling optimization.

Details

Journal of Quality in Maintenance Engineering, vol. 25 no. 1
Type: Research Article
ISSN: 1355-2511

Keywords

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Article

Jakiul Hassan, Faisal Khan and Mainul Hasan

Purpose – The purpose of this paper is to propose a risk‐based approach for spare parts demand forecast and spare parts inventory management for effective allocation of…

Abstract

Purpose – The purpose of this paper is to propose a risk‐based approach for spare parts demand forecast and spare parts inventory management for effective allocation of limited resources. Design/methodology/approach – To meet the availability target and to reduce downtime, process facilities usually maintain inventory of spare parts. The maintaining of non‐optimized spare parts inventory claims more idle investment. Even if it is optimized, lack of attention towards the critical equipment spares could threaten the availability of the plant. This paper deals with the various facets of spare parts inventory management, mainly risk‐based spare parts criticality ranking, forecasting, and effective risk reduction through strategic procurement policy to ensure spare parts availability. A risk‐based approach is presented that helps managing spare parts requirement effectively considering the criticality of the components. It also helps ensuring the adequacy of spare parts inventory on the basis of equipment criticality and dormant failure without compromising the overall availability of the plant. Findings – The paper proposes a risk‐based approach that used conjugate distribution technique with the capability to incorporate historical failure rate as well as expert judgment to estimate the future spare demand through posterior demand distribution. The approach continuously updates the prior distribution with most recent observation to give posterior demand distribution. Hence the approach is unique in its kind. Practical implications – Appropriate spare parts unavailability could have great impact on process operation and result in costly downtime of the plant. Following proposed approach the availability target can be achieved in process industry having limited maintenance resources, by forecasting spare parts demand precisely and maintaining inventory in good condition. Originality/value – Adopting the approach proposed in the paper, risk level can be minimized and plant availability can be maximized within the financial constraint. The resources are allocated to the most critical components and thereby increased availability, and reduce risk.

Details

Journal of Quality in Maintenance Engineering, vol. 18 no. 3
Type: Research Article
ISSN: 1355-2511

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Article

H. Yamashina and H. Mizuyama

In most automated assembly systems, each product is inspected after every assembly operation and, if it is found to be defective, it will be repaired or scrapped…

Abstract

In most automated assembly systems, each product is inspected after every assembly operation and, if it is found to be defective, it will be repaired or scrapped immediately. This ensures the quality of the outputs of the systems, but it also causes a short stop of the assembly line. This paper shows that the number of short stops can be reduced by installing inspection stations and repair stations strategically. Then, an optimizing problem of placing these stations under a given assembly sequence is formulated and an algorithm is given to this problem. Further, the problem of not only placing these stations but also determining the assembly sequence is formulated and an algorithm to solve the problem is developed. Finally, numerical examples are given to illustrate the efficiencies of the algorithms.

Details

Journal of Quality in Maintenance Engineering, vol. 4 no. 2
Type: Research Article
ISSN: 1355-2511

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Article

Xiang Xie, Qiuchen Lu, David Rodenas-Herraiz, Ajith Kumar Parlikad and Jennifer Mary Schooling

Visual inspection and human judgement form the cornerstone of daily operations and maintenance (O&M) services activities carried out by facility managers nowadays. Recent…

Abstract

Purpose

Visual inspection and human judgement form the cornerstone of daily operations and maintenance (O&M) services activities carried out by facility managers nowadays. Recent advances in technologies such as building information modelling (BIM), distributed sensor networks, augmented reality (AR) technologies and digital twins present an immense opportunity to radically improve the way daily O&M is conducted. This paper aims to describe the development of an AR-supported automated environmental anomaly detection and fault isolation method to assist facility managers in addressing problems that affect building occupants’ thermal comfort.

Design/methodology/approach

The developed system focusses on the detection of environmental anomalies related to the thermal comfort of occupants within a building. The performance of three anomaly detection algorithms in terms of their ability to detect indoor temperature anomalies is compared. Based on the fault tree analysis (FTA), a decision-making tree is developed to assist facility management (FM) professionals in identifying corresponding failed assets according to the detected anomalous symptoms. The AR system facilitates easy maintenance by highlighting the failed assets hidden behind walls/ceilings on site to the maintenance personnel. The system can thus provide enhanced support to facility managers in their daily O&M activities such as inspection, recording, communication and verification.

Findings

Taking the indoor temperature inspection as an example, the case study demonstrates that the O&M management process can be improved using the proposed AR-enhanced inspection system. Comparative analysis of different anomaly detection algorithms reveals that the binary segmentation-based change point detection is effective and efficient in identifying temperature anomalies. The decision-making tree supported by FTA helps formalise the linkage between temperature issues and the corresponding failed assets. Finally, the AR-based model enhanced the maintenance process by visualising and highlighting the hidden failed assets to the maintenance personnel on site.

Originality/value

The originality lies in bringing together the advances in augmented reality, digital twins and data-driven decision-making to support the daily O&M management activities. In particular, the paper presents a novel binary segmentation-based change point detection for identifying temperature anomalous symptoms, a decision-making tree for matching the symptoms to the failed assets, and an AR system for visualising those assets with related information.

Details

Engineering, Construction and Architectural Management, vol. 27 no. 8
Type: Research Article
ISSN: 0969-9988

Keywords

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Article

Valerie Fogleman

The purpose of this article is to examine the regime to remediate contaminated land in the UK set out in Part 2A of the Environmental Protection Act 1990 and to analyse…

Abstract

Purpose

The purpose of this article is to examine the regime to remediate contaminated land in the UK set out in Part 2A of the Environmental Protection Act 1990 and to analyse the UK Government's intent and objectives in introducing the regime. The legislative provisions and the statutory guidance that accompanies that legislation are then analysed to determine whether those objectives could have been met.

Design/methodology/approach

A research approach was taken to trace the legislative history of Part 2A and to analyse the statutory provisions and the statutory guidance. The approach included researching Parliamentary debates on the statute, consultations on the statutory guidance, other information published by the UK Government, commentaries on the regime, and contaminated land regimes in other jurisdictions.

Findings

The paper found that the introduction of a contaminated land regime that delegates primary implementation and enforcement authority to local authorities, and that severely limits their discretion in doing so, has resulted in a regime that has proven to be unworkable in practice and that has failed to meet its objectives.

Originality/value

The article is the first paper to examine the legislative intent and objectives behind Part 2A and to analyse their effect on the provisions in the statute and the statutory guidance and their implementation and enforcement.

Details

International Journal of Law in the Built Environment, vol. 6 no. 1/2
Type: Research Article
ISSN: 1756-1450

Keywords

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Article

Anis Chelbi, Daoud Ait‐Kadi and Houda Aloui

The purpose of this study is to propose and model an inspection and preventive maintenance policy for randomly failing systems that alternate operating and idle periods…

Abstract

Purpose

The purpose of this study is to propose and model an inspection and preventive maintenance policy for randomly failing systems that alternate operating and idle periods according to their mission profile.

Design/methodology/approach

A maintenance policy is defined and modeled mathematically. The paper focuses on finding the age T for inspection which maximizes the stationary availability of the system.

Findings

Except for the case of only self‐announcing failures, there always exists a finite optimal strategy T*. Two sufficient conditions for the uniqueness of such an optimum are also derived.

Practical implications

Many productive systems alternate operating and inactive periods, their failures may be self‐announcing or not self‐announcing (detected only through inspection). This paper presents a maintenance strategy for such systems in order to maximize their stationary availability. The proposed strategy suggests submitting the system to inspection when its age reaches T units of time.

Originality/value

This paper states a general expression of the system stationary availability which is considered as the performance criterion. Conditions of existence and uniqueness of an optimal strategy are developed.

Details

Journal of Quality in Maintenance Engineering, vol. 14 no. 1
Type: Research Article
ISSN: 1355-2511

Keywords

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Article

Birendra K. Mishra and Ashutosh Prasad

Employee theft is a major component of retail shrinkage. The purpose of this paper is to analyze the use of two methods, internal control and random inspections of the…

Abstract

Purpose

Employee theft is a major component of retail shrinkage. The purpose of this paper is to analyze the use of two methods, internal control and random inspections of the locations at which employees work, to deter employee theft. An inspection strategy is designed in which retailers try to minimize their costs while trying to prevent employees from stealing.

Design/methodology/approach

We employ an analytical approach. The employees are assumed to be strategic, i.e. they respond to the decisions made by the retailer, and likewise the retailer is strategic. Consequently, game theory is used to model their interaction, and to obtain the best decisions for both the retailer and employee after taking into consideration the other's actions.

Findings

The solution of the game depends upon various parameters such as the cost and effectiveness of random inspections and of the internal control system. The paper determines the optimal frequency of inspections, the total budget to be spent on inspections and the total expected retail shrinkage due to employee theft. The paper also shows the extent to which an effective internal control system and the recruitment of honest employees can benefit retail organizations in preventing losses due to employee theft.

Practical implications

The paper provides normative guidelines for decisions such as the frequency of inspections. Retailers can limit employee theft but eliminating theft altogether turns out to be too expensive if the goal is to minimize organizational losses. The retailer should try to reduce inspection costs and increase their effectiveness. Adding honest employees helps the retailer, but note that adding just a few is not beneficial because organizational losses remain unchanged, but adding a larger number qualitatively affects the equilibrium outcome and lowers organizational losses. The paper describes when investing in better internal control systems is appropriate.

Originality/value

The underlying assumption is of strategic retailers and employees. This gaming analysis brings a new perspective to examining retail crime problems than has been hitherto the case. This work follows in the tradition of the economics of crime literature, which views crime as a rational choice decision made by potential offenders. The study examines employee crime in the context of retail organizations, and provides several new insights. Although the idea of random inspections is not new, features of the retail environment such as internal control system, employee dissatisfaction and the ability to recruit honest employees have no direct parallels in the economics of crime literature, and are being touched upon for the first time.

Details

International Journal of Retail & Distribution Management, vol. 34 no. 11
Type: Research Article
ISSN: 0959-0552

Keywords

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Article

James D.T. Tannock

Control charts for statistical quality control have been the subject of academic study for many years. Various analytical approaches to economic control chart design have…

Abstract

Control charts for statistical quality control have been the subject of academic study for many years. Various analytical approaches to economic control chart design have been advanced, although none has found wide use in practice. Describes a simulation approach to the investigation of control chart economics. Simulation can provide guidance on chart design issues such as sample size, sampling interval and the use of alternative chart alarm rules. Applies the method to the economic comparison between variables control charting and other inspection strategies such as 100 per cent inspection. Presents some generalized results, allowing comparison to be made for various scenarios. Emphasizes the importance of process capability in the choice of quality control strategy and demonstrates the economic advantages of control charting where special or assignable causes exist.

Details

International Journal of Quality & Reliability Management, vol. 14 no. 7
Type: Research Article
ISSN: 0265-671X

Keywords

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