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Population models have been developed for large‐scale maintenance requirements planning. However, these models assume that all component groupings are equally important or…
Population models have been developed for large‐scale maintenance requirements planning. However, these models assume that all component groupings are equally important or critical to the functioning of the overall system. Importance measures from the literature are reviewed and modified to accommodate varying age groupings of identical components. By measuring the relative importance of component groupings in population models, an analyst will be able to identify those component groupings which merit further research and development in an attempt to increase overall system reliability at minimum cost. Numerical examples are presented for the cases of components with and without repair after failure.
A probabilistic methodology is discussed for the evaluation of maintenance requirements and expected costs for large‐scale logistics systems. A multitude of identical…
A probabilistic methodology is discussed for the evaluation of maintenance requirements and expected costs for large‐scale logistics systems. A multitude of identical system components that are used to support operations characterise large‐scale systems. These identical components can be grouped together, and “representative” maintenance characteristics used in lieu of individual component tracking to perform a strategic analysis. The combination of these component “groupings” forms a population. The benchmark results are presented from a previous study of a population of US Navy tugs. Benchmark parameters are then varied in ten different maintenance scenarios to demonstrate the use of population models to analyse strategically the trade‐off between expected population costs and system availability.
The development of labour standards for the single truss tomatoproduction system is examined. Both time study and predetermined timesystems, such as the Element Times for…
The development of labour standards for the single truss tomato production system is examined. Both time study and predetermined time systems, such as the Element Times for Agriculture (ETA) tables and the Maynard Operation Sequence Technique (MOST) tables, are used to determine labour standards for the operations of pruning and harvesting in a single truss tomato production system. The hypothesis is that a predetermined time system could be used to establish greenhouse labour standards, and thus replace the tedious and costly process of direct time study. Such a work measurement system would enable the setting of job standards quickly and accurately. Standardised work models will facilitate cost control of labour operations, and provide data for evaluation of labour costs within future greenhouse system designs. The data indicate that, although the pre‐determined time values varied from measured time study by around 6 per cent to over 23 per cent for pruning, the variation for harvesting ranged approximately from 3 per cent to 7 per cent. The combined results suggest that predetermined time systems can be used effectively to establish greenhouse labour standards for short cycle tasks without the loss of significant accuracy when using an absolute scale.
This article presents an integrated methodology for the inclusionof a facility′s interactions with the outside environment, and theimpact of those interactions on the…
This article presents an integrated methodology for the inclusion of a facility′s interactions with the outside environment, and the impact of those interactions on the location of entrances and exits within the facility. For example, the outside interactions generated by shipping and receiving activities will significantly influence the location of facility ingress/egress points. The “practical layout planning” (PLP) methodology integrates both layout construction and improvement techniques. The principal idea in this methodology is that departments within a facility be “condensed” into a number of “points”. In the layout construction phase, the relative location of these points is determined using multifacility location theory, where the facility′s interactions with the outside environment are represented by “contact points” and the departments in the layout are analogous to the new facilities to be located. Once these relative departmental positions are obtained, the “points” are then adjusted for areas to obtain a constructed layout. In the improvement technique, intra‐departmental flows are optimised by the optimal location of ingress/egress points which are determined by again using multifacility location theory. Interdepartmental flow is optimised by minimising the distance between departments as indicated by their closest ingress/egress points. The objective is to obtain a minimum total flow‐cost by interchanging departmental locations without violating physical constraints. The PLP methodology is demonstrated with a modest example.
The purpose of this paper is to present a procedure to implement time-driven activity-based costing (TDABC) using Maynard Operation Sequence Technique (MOST). In this…
The purpose of this paper is to present a procedure to implement time-driven activity-based costing (TDABC) using Maynard Operation Sequence Technique (MOST). In this paper three research questions are addressed: How can MOST be used to frame time equations? How can MOST be used for the improvement of productivity? How can TDABC cost information be used?
Case study research was performed at a manufacturing industry. Data have been collected for overhead distribution. The overhead cost was distributed on activity. Time equations are framed using MOST. Cost of activity is assigned to the product using time equations.
The proposed system simplifies the process of implementation of TDABC using MOST. This system not only determines the cost but also identifies the area where cost is consumed. It also identifies opportunity for productivity improvement.
The case study was conducted in a manufacturing industry. The proposed methodology is suitable for manufacturing industry where standard work procedure is adapted.
The study explains the implementation of TDABC using MOST using a case study and results are meticulously discussed from a management point of view for appropriate decision making.
Besides the articles published so far dealing with the implementation of TDABC, no research was found on the implementation of TDABC using MOST.
Airline business management is set on airworthy strategy. Airline sustainability depends upon corporate-based airworthy strategy as airworthiness is the base to any…
Airline business management is set on airworthy strategy. Airline sustainability depends upon corporate-based airworthy strategy as airworthiness is the base to any airline business management and strategy. An airline can ensize its corporate sustainability if it has airworthiness strategy and risk management. The main condition to survive in the airline business is to maintain airworthiness with the fleet, maintenance and corporate-risk management. Aircraft maintenance technician (AMT) has a dual role in aircraft maintenance system as the source of failure in maintenance process via his volatility and unmanageable qualifications and secondly source of manager of maintain airworthiness of the aircrafts in airline. Situational awareness of managers about both limitations and qualifications of human factors is vital determinant to the decision-making process in aviation. Although continuously improving in related literature, one of the biggest weaknesses of the current methods of AMT error or performance is that the ability to model the reciprocal effects of the factors affecting the fault is limited. For this reason, this study aims to develop an analytic network process (ANP) model that takes into account the effects of mutual dependences among factors.
Firstly, with the help of experts and extensive literature, 67 factors that contributed to AMT error are identified and grouped. Then, the factors identified as eligible criteria and sub-criteria that contributed to the AMT errors are determined. In this study, the weights of identified criteria that have influence on AMT error try to determine by using ANP method. ANP is the common method to solve multi-criteria decision-making problems and is used to calculate priorities of factors. Criteria determined in this study are classified into three main clusters: “individual-related criteria”, “working environment-related criteria” and “organisational-related criteria”. These main clusters include 15 sub criteria such as communication, documentation (quality/updating/availability) and peer pressure.
The result of this study shows that time pressure, organisational culture, safety culture and supervision are the most important criteria that contributed to AMT error. Their weights are 0.207, 0.172, 0.102 and 0.094, respectively.
There are many difficulties and limitations in measuring the factors that have an influence on AMT errors. For this reason, the weights of criteria and sub-criteria necessary are determined using ANP, and in this manner, it is possible to make better decisions in this process as ANP is a multi-criteria decision-making technique that considers qualitative factors in decision-making problems. The factors’ taxonomy determined as a result of the expert opinions and the extensive literature and the ANP model developed taking into account the dependencies between the factors will contribute to the literature.