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This work contributes two novel modified Taguchi techniques to the optimal parametric setting for minimum water absorption in epoxy composites. Taguchi method, using ASTM standards was applied with factors (initial weight, final weight, length, sample thickness and time of immersion) and four levels in the experimental design. The analysis of variance (ANOVA) evaluates the significance and individual contributions of the parameters. The optimal parametric setting was A1B4C3D4E1 (initial weight, 2.61 g; final weight, 2.69 g; length, 62.73 mm; thickness, 3.88 mm; time, 15.65 hrs). The ANOVA identifies time and length as dominant parameters (98.98 and 1.02 % contributions, respectively). Taguchi-Pareto analysis found only factor-level from the time and length parameters economical to optimality. The Taguchi-ABC analysis revealed the individual weights and contributions of the factor-level irrespective of its initial groupings. The new Taguchi techniques highlighted the importance of time and length of sample in obtaining minimum water absorption of composites.

Purpose Maintenance plans are programmes, which follow maintenance appraisals, contain information of what to do and the time approximates for accomplishments. They also deal with how to carry out maintenance jobs. In contemporary period, curiosity has proliferated about how sustainability affects manufacturing plans. The purpose of this paper is to offer a comprehensive notion of maintenance sustainability in maintenance planning. The literature has downplayed maintenance sustainability but may support in understanding how to crack the present company-community conflicts about the negative influence of manufacturing on the environment. Design/methodology/approach This study develops the idea of selecting the proper maintenance strategy based on integrated fuzzy axiomatic design (FAD) principle and fuzzy-TOPSIS. This work suggests that the maintenance function is an uncertain, activity-oriented system. To fully appreciate the proposed framework, the work employs data from a cement manufacturing plant to test the structure. This study offers 20 influential factors on which it build the fundamental structure of maintenance system sustainability for manufacturing concerns. A novel literature contribution that departs from existing conceptions is the classical determination of weights of each sustainability factor, employing fuzzy entropy weighting approach. Furthermore, work innovatively determines the ranking of some important tenets of sustainability in maintenance and optimises the maintenance consumables employing the FAD principle. Findings Interestingly, the output of the investigation revealed differences as the work adopts fuzzy-TOPSIS in comparison with FAD principle. Originality/value Case examination of a real-life manufacturing venture validated the claims, showing maintenance workforce training as a top-echelon strategy for maintenance system sustainability.

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Purpose -The paper presents a mathematical model that measures the profitability of the maintenance system based on the traditional accounting definition of profitability. There is currently a dire need for an article presenting a scientific-based framework for practitioners in maintenance to make optimal instead of sub-optimal decisions on profitability. Design/methodology/approach -A case study is presented to reflect the actual application of the proposed model. Different situations were considered in modelling to obtain optimal results. Simulation experiments were conducted to demonstrate that maintenance profitability is a reality through the use of differential calculus. Findings -It was observed that the approach presented is a holistic viewpoint of maintenance profitability measurement. Research limitations/implications -An adequate understanding of the maintenance system is needed to properly implement the model. Practical implications -The practical application of the model is that the maintenance system will now be viewed as a value-adding activity instead of "a necessary evil" or "a bottomless pit for expenses". Originality/value -This paper fulfils an identified need and offers practical help to managers in taking guided decisions that are optimal.

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Road bumps play a crucial role in enforcing speed limits, thereby preventing overspeeding of vehicles. It significantly contributes to the overall road safety objective through the prevention of accidents that lead to deaths of pedestrians and damage of vehicles. Despite the importance of road bumps, very little research has been done to investigate into their design. While documentation exists on quantitative descriptions of road bumps, they offer little guidance to decision making. This work presents a unique approach to solving road bumps design problems. The results of our study reveal three important road bumps variables that influence the control of vehicle speeds. The key variables are bump height, bump width, and effective distance between two consecutive road bumps. Since vehicle speed control is the ultimate aim of this study the relationship between vehicle speed and other variables earlier mentioned is established. Vehicle speed is defined as the product of frequency at which a vehicle is moving over road bumps and the sum of effective distance between two consecutive road bumps. In the determination of bump height we assume a conical shaped curve for analysis as a matter of research strategy. Based on this, two stages of motion were analysed. The first concerns the motion over the bump itself while the second relates to the motion between two consecutive road bumps. Fourier series was then used to formulate a holistic equation that combines these two stages. We used trigonometric functions to model the behaviour of the first stage while with the second stage giving a functional value of zero since no changes in height are observed. We carried out vibration analysis to determine the effect of road bumps on a vehicular system. Arising from this a model component is referred to as an isolation factor. This offers guidance to the safe frequency at which vehicles could travel over road bumps. The work appears to contribute to knowledge in road bump research through the development of a novel approach to the control of vehicle speeds. Significant research progress could be made if engineering and academic communities at large appreciate our viewpoints. With this work it is apparent that varying of the assumptions made in terms of bump shape may produce high proliferation of beneficial research studies. Although this work may reveal a new way of investigation into road bump research, no claim is made for the work comprehensiveness. We expect experts to challenge some of our thoughts and ideas presented in this work.

The growing interest in technicians' workloads research is probably associated with the recent surge in competition. This was prompted by unprecedented technological development that triggers changes in customer tastes and preferences for industrial goods. In a quest for business improvement, this worldwide intense competition in industries has stimulated theories and practical frameworks that seek to optimise performance in workplaces. In line with this drive, the present paper proposes an optimisation model which considers technicians' reliability that complements factory information obtained. The information used emerged from technicians' productivity and earned-values using the concept of multi-objective modelling approach. Since technicians are expected to carry out routine and stochastic maintenance work, we consider these workloads as constraints. The influence of training, fatigue and experiential knowledge of technicians on workload management was considered. These workloads were combined with maintenance policy in optimising reliability, productivity and earned-values using the goal programming approach. Practical datasets were utilised in studying the applicability of the proposed model in practice. It was observed that our model was able to generate information that practicing maintenance engineers can apply in making more informed decisions on technicians' management.