S.A. Oke and O.E. Charles‐Owaba
This paper aims to revisit the preventive maintenance scheduling literature. The problem to be solved is the simultaneous scheduling of resource‐constrained preventive maintenance…
Abstract
Purpose
This paper aims to revisit the preventive maintenance scheduling literature. The problem to be solved is the simultaneous scheduling of resource‐constrained preventive maintenance and operations. In particular, the expression that defines the period‐dependent cost function for a preventive maintenance scheduling activity is redefined. A case study is presented from the shipping industry.
Design/methodology/approach
In this paper a mathematical theory of differential calculus known as three‐dimensional wave equation is applied. The methodology involves transforming the preventive maintenance cost function that is expressed in terms of several variables into a more precise framework. The motivation for the work is the need to measure the total preventive maintenance scheduling cost more precisely than with the use of the existing linear cost structure.
Findings
In this paper the findings from the analysis carried out found evidence that validates the claim of the feasibility of analyzing preventive maintenance cost using the approach proposed.
Research limitations/implications
The paper shows that, in practice, maintenance managers strive to reduce the cost of preventive maintenance activities in order to achieve low cost production of goods. This would encourage a high patronage of customers and prevent decisions being made on wrong data. The approach presented here aims at correcting this weakness by revealing a more precise and reliable method of preventive maintenance scheduling cost computation. This is a scientific tool that should be of immense benefit to maintenance planners, particularly those actively engaged in scheduling functions.
Originality/value
The work in this paper is new, since a novel framework is presented in a way that has not been documented earlier.
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S.A. Oke and O.E. Charles‐Owaba
The purpose of this paper is to work on an analytical approach to test sensitivity of a maintenance‐scheduling model. Any model without sensitivity analysis is a “paper work”…
Abstract
Purpose
The purpose of this paper is to work on an analytical approach to test sensitivity of a maintenance‐scheduling model. Any model without sensitivity analysis is a “paper work” without advancing for wider applications. Thus, the simulation of simultaneous scheduling of maintenance and operation in a resource‐constrained environment is very important in quality problem and especially in maintenance.
Design/methodology/approach
The paper uses an existing model and presents a sensitivity analysis by utilising an optimal initial starting transportation tableau. This is used as input into the Gantt charting model employed in the traditional production scheduling system. The degree of responsiveness of the model parameters is tested.
Findings
The paper concludes that some of these parameters and variables are sensitive to changes in values while others are not.
Research limitations/implications
The maintenance engineering community is exposed to various optimal models in the resource‐constraint‐based operational and maintenance arena. However, the models do lack the sensitivity analysis where the present authors have worked. The work seems significant since the parameters have the boundary values so the user knows where he can apply the model after considering the constraints therein.
Originality/value
The underlying quest for testing the sensitivity of the model parameters of a maintenance scheduling model in a multi‐variable operation and maintenance environment with resource constraints is a novel approach. An optimal solution has to be tested for robustness, considering the complexity of the variables and criteria. The objective to test the model parameters is a rather new approach in maintenance engineering discipline. The work hopefully opens a wide gate of research opportunity for members of the maintenance scheduling community.
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S.A. Oke and O.E. Charles‐Owaba
The simultaneous scheduling of resource‐constrained maintenance and operations is addressed in this work. The purpose of the paper is to capture the uncertainty in the development…
Abstract
Purpose
The simultaneous scheduling of resource‐constrained maintenance and operations is addressed in this work. The purpose of the paper is to capture the uncertainty in the development of a model that schedules both preventive maintenance and operational activities. Fuzzy logic is employed to transform the human expertise into IF‐THEN rules.
Design/methodology/approach
The approach has the advantage of revealing semantic uncertainty with the associated non‐specifying measures. The methodology applied tracks the error values in terms of results in linguistic variable.
Findings
The results obtained indicate the feasibility of tracking the uncertain measures in the model discussed. Thus, the study may be applicable to both production system and transportation organizations that are engaged in both maintenance and operational activities.
Practical implications
The research has serious implication in terms of the ability to monitor the imprecision that were introduced in the previous models. This obviously provides a more reliable framework for researchers and practitioners interested in maintenance scheduling activities.
Originality/value
The paper is new in that it demonstrates the application of fuzzy logic in a form that was never documented.
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K.A. Adebiyi, O.E Charles‐Owaba and M.A. Waheed
Managing a safety programme and ensuring that change is in accordance with suitable performance measures requires continuing improvement in the support of analytical power and…
Abstract
Purpose
Managing a safety programme and ensuring that change is in accordance with suitable performance measures requires continuing improvement in the support of analytical power and empirical information. This paper aims to consider different approaches and modeling efforts on safety performance evaluation.
Design/methodology/approach
Review and synthesis of literature.
Findings
Ten major safety performance evaluation approaches are identified including expectation function, risk assessment, statistical quality control, price deflation, engineering economic factor, system analysis, artificial intelligence, and systems theory. Based on the approaches, quantitative and qualitative models have been proposed. The quantitative models use measuring indicators such as frequency, severity, percentages, relative weight and economic gains/loss of safety programme. However, qualitative models employ hazard analysis and hazard operability.
Research limitations/implications
Several research questions remain to be answered in order to completely improve and optimize the impact of these provisional safety performance measures.
Originality/value
This study offers a set of interesting lessons for academics, industry and safety practitioners by providing guidelines that will assist in ensuring a correct focus to select an appropriate safety performance evaluation model.
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O.G. Akanbi, O.E. Charles‐Owaba and A.E. Oluleye
The purpose of this paper is to identify the factors responsible for road traffic accidents among commercial commuter drivers in Lagos, Nigeria.
Abstract
Purpose
The purpose of this paper is to identify the factors responsible for road traffic accidents among commercial commuter drivers in Lagos, Nigeria.
Design/methodology/approach
A total of 188 commercial drivers, driving 18‐seater mass transit buses in inter‐city highways were studied. Their accident records for the previous three years collected from Police records, Federal Road Safety Commission records, self‐administered questionnaires and observation of driving habits of the drivers. Their eye status were measured and data also collected from the Driver Union's Insurance Agency. A total of 25 human factor variables, identified as possible contributors to road traffic accidents were studied.
Findings
Six variables were found as possible significant contributors to road traffic accidents. They are old age, overtaking, overspeeding, religious affiliation, bad brake conditions and use of bad tyres. When the variables were subjected to two‐way interactions, 44 variable combinations were significant (p < 0.05) with R2 of 0.994 and residual error of 1.165.
Research limitations/implications
Accidents are not usually caused by single variables but by a combination of variables.
Originality/value
Apart from variables commonly found in the literature as possible causes of road traffic accidents, there may be some factors that may be peculiar to some countries like religious affiliation, belief in use of charms to protect drivers from accident and eye problems that are not identified because of lack of regular tests among others.
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O.E. Charles‐Owaba and K.A. Adebiyi
The manufacturing industry perceives government standards as an attempt to unnecessarily increase production cost. This may be due to lack of acceptable models for demonstrating…
Abstract
Purpose
The manufacturing industry perceives government standards as an attempt to unnecessarily increase production cost. This may be due to lack of acceptable models for demonstrating the associated benefits to industry. It was the goal of this study to develop a simulation model for predicting the performance of a manufacturing safety programme (SP).
Design/methodology/approach
The principles of system‐dynamics were applied to identify the relevant safety‐related components and their relationships. A simulation model for evaluating periodic performance of a manufacturing SP was then developed. A set a dynamic equations for predicting factory accidents or preventions and the monetary saving were the performance measures. Two set of factory data: non‐SP (1979) and SP (1991‐2004) were collected from a bottling company. The parameters of the model were estimated using the first set while it was validated with the second and associated monetary saving computed.
Findings
Solutions to factory accidents or preventions yielded exponential functions. The means and standard deviations of the predicted and actual accidents were 32 and 5.66; and 30 and 7.46, respectively. The corresponding values for predicted and actual preventions were 55 and 10.47; and 59 and 7.45, respectively. There were no significant differences between the predicted and actual for the accidents and preventions, respectively, at 5 per cent level. The predicted SP saving per annum was 6.96 millions.
Originality/value
The model is a useful tool for setting profitable manufacturing safety standards and effective SP management.
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K.A. Adebiyi, S.O. Jekayinfa and E.O. Charles‐Owaba
This paper aims to investigate the safety practices in some selected agro‐allied industries in south‐western Nigeria with a view to analysing the degree of safety awareness;…
Abstract
Purpose
This paper aims to investigate the safety practices in some selected agro‐allied industries in south‐western Nigeria with a view to analysing the degree of safety awareness; adequacy of safety equipment; extent of enforcing safety rules; effectiveness of safety‐related activities and economics of safety programme.
Design/methodology/approach
A case study method of investigation, field study guidelines and binary variable were used and information gathered from 36 industries was documented. The data collected were analysed using mean, percentage and standard mathematical models. The analyses carried out on the data gathered are presented on the following: occurrence of accidents, causes of accidents, damages resulting from accidents, accident prevention activities and economic implications.
Findings
Three classes of accidents are identified as fatal, serious, and minor. The results showed that minor accident has the highest frequency of occurrence of 304, while fatal accident has the least frequency of occurrence of 17. However, serious accident has the greatest economic implication, accounting for annual average loss of $4.97 millions. Also, nine causes of accidents are identified, out of which faulty equipment is common to all industries. And eight accident prevention activities are identified, amongst which standard operating procedure, good housekeeping and on‐the‐job training are commonly being practised, while provision of safety handbook and policy is least practised.
Originality/value
This paper has described the safety practices in 15 agro‐allied industries with an organised safety programme in South Western Nigeria. The study has investigated the extent of enforcement of safety rules; safety awareness; and economic implication of accidents from this sector for the national economy.
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S.A. Oke, O.E. Charles‐Owaba, A.O. Johnson and O.O. Omogoroye
This paper aims at developing a methodology capable of controlling accidents and failures in oil and gas production activities.
Abstract
Purpose
This paper aims at developing a methodology capable of controlling accidents and failures in oil and gas production activities.
Design/methodology/approach
Fuzzy analysis that is based on fuzzy linguistics, rule matrix, rule structures, and system operating rules is utilised. Fuzzy methodology is applied to develop a safety control model for the prevention of accidents and failures in oil and gas production activity offshore platforms.
Findings
The model is demonstrated with a case study, thereby suggesting the feasibility of the applied approach in practical cases.
Practical implications
Primarily, the study aims to guarantee safety. Also uncertainties and imprecision that commonly characterize safety measurement systems are tracked. The time‐consuming activity in measurement and the requirement of lots of specific information about the process is avoided.
Originality/value
The results from the study provide valuable baseline information for future research investigating how safety of oil platforms is affected by some factors.
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The purpose of this paper is to employ a system dynamics approach to develop a mathematical model for managing magnitude and risk factors of injuries in a manufacturing industry…
Abstract
Purpose
The purpose of this paper is to employ a system dynamics approach to develop a mathematical model for managing magnitude and risk factors of injuries in a manufacturing industry. This is to provide the decision makers with a systemic‐strategy to capture the transition of industries, especially manufacturing, into world‐class safe workplaces.
Design/methodology/approach
An accident investigation register was administered to capture needed data to estimate the model parameters and identify risk factors of injuries. The principle of system dynamics (SD) was employed to identify the relevant safety‐related components and their interrelationships. Applying the concept of causality analysis, causal loop and SD flow diagrams indicating how prevention activities may eliminate hazardous conditions were delineated and a mathematical model to predict the main variables involved in manufacturing safety programme was formulated.
Findings
The validity of the model was demonstrated using the observed data from accident investigation and register review; and a satisfactory agreement was found between the observed data and the model predictions.
Practical implications
The proposed model's attribute of predicting the probability of injuries or preventions is remarkable and thus, useful for managing sustainable safety control programmes.
Originality/value
This paper presents a manufacturing safety programme using equation‐oriented technique to predict the main variables required for managing magnitude and risk factors of injuries in a manufacturing plant.
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K.A. Adebiyi and O.E. Charles‐Owaba
The manufacturing industry in Nigeria often perceives government safety standards as an attempt to increase production cost. This is due to lack of acceptable template for setting…
Abstract
Purpose
The manufacturing industry in Nigeria often perceives government safety standards as an attempt to increase production cost. This is due to lack of acceptable template for setting an attainable standards and safety programme to the manufacturing industry. It is the goal of this work to develop such a template for an effective and sustainable manufacturing safety programme.
Design/methodology/approach
A total of 30 manufacturing firms were examined and five experienced manufacturing, and three safety engineers interviewed for information on types of SP activities. Review and synthesis of literature was carried out.
Findings
Four types of accidents are identified as fatal, serious, minor and trivial wounds. Accidents causing factors are classified into human factor, deficient maintenance of facilities and environmental factors. The prevention activities were categorized into training, guarding, awareness, incentive, accident investigation and personal protective equipment (PPE).
Practical implications
This study provides baseline information for academics, industry and safety practioners to setting an attainable and effective manufacturing safety programme.
Originality/value
The paper suggests a mathematical approach for developing a manufacturing safety programme.