Maintenance is usually considered as a cost-centre or necessary evil, because (according to this aspect) it costs the company unnecessarily big budget, while it should be treated as a profit-generating centre. The problem addressed in this paper is that if maintenance is a profit contributor how does maintenance technical impact transfer to the plant other activities such as production, quality and tied up capital, and how can this effect ultimately influence company's profit and competitiveness?
In this paper, we discuss maintenance role in maintaining the quality of the essential elements contribute in the manufacturing process such as production/operation and quality on the economic basis for achieving the competitive advantages desired. Interactions between maintenance, production and quality, and how simple technical effects of maintenance in the operative level can be transferred to the economic effect in the strategic level influencing company’s profitability and competitiveness is discussed. A model describes the mechanisms through which vibration-based maintenance (VBM) impact is transferred to the plant other activities and company's business is developed and verified using real and typical data based on the author’s experience in the Swedish paper mills.
The main result of this study is developing a model for converting vibration-based maintenance technical to financial impact and assessing it. The model potential and applicability is tested using a combination of real and typical data. The result also demonstrates how the potential of the VBM impact on the production, quality, tied up capital and different relevant expenses can be assessed financially. Furthermore, the model can be utilised for two additional objectives; for examining whether the investment done in maintenance is cost-effective or not, and simulating maintenance financial impact on the relevant working areas in order to assess the investment required before selecting and applying the improvement plan. The major conclusions are; applying the model, VBM policy can be introduced as a profit centre, and identifying the transferring mechanisms of maintenance impact highlights where, why and how much should be invested in order to enhance production and maintenance performance continuously and cost-effectively.
We assess the most popular maintenance approaches, i.e. strategies, policies, or philosophies, using a fuzzy multiple criteria decision making (MCDM) evaluation methodology. We illustrate with two examples how the suggested evaluation methodology identifies the most informative approach. Using the fuzzy MCDM, it would be possible to select in advance, the most informative (efficient) maintenance approach. Consequently, this leads to less planned replacements, and failures would be reduced to approximately zero and higher utilization of component life can be achieved. Thus, the maintenance department could contribute more to the business objectives throughout participating effectively in adding value to the production activities.
The purpose of this paper is to investigate the maintenance practices that are used in Swedish industry. The study was performed by conducting a cross-sectional survey within Swedish firms that have at least 100 employees. The main results achieved from the study show that the role of maintenance is not highly recognised. There is a need to spend and invest more in maintenance, which is considered by the majority of Swedish industries as a necessary expense. Although about 13% of the maintenance department time is spent on planning maintenance tasks, nevertheless, about one third of the time is spent on unplanned tasks. There is a need for more adoption of maintenance concepts such as total productive maintenance (TPM) and reliability-centred maintenance (RCM). The lack or ineffectiveness of planning and scheduling can significantly restrict the maintenance department in achieving its objectives and can thus prevent the company from maximising business profits and offering competitive advantages.
We consider the problem of choosing the holding cost in inventory models. Traditionally, the cost of holding inventory is assumed to increase linearly with a rate that is equal to a percentage of the product value. This since the capital cost is believed to make up the main part of the cost. However, recent research indicates that this is not necessarily the case.
In the present work, we present a more general model of the cost of holding inventory based on a microeconomic framework. A method for determining a suitable holding cost per unit and time unit, h, which can be used in existing heuristics/formulas is derived. The method is based on the ideas behind activity-based costing (ABC).
The suggested method works well in the considered numerical examples (maximum and average cost increase is 1.78% resp. 0.08%). There exist situations where the traditional approach, i.e., setting h as a percentage of the product value, gives rise to a significant cost increase (>15%).
This paper investigates the delay experienced by retailers in a distribution system due to shortages at the central warehouse. Simple formulae are developed to estimate the mean and variance of this delay. The formulae are based on replacing the stochastic lead-time demand with a stochastic demand rate, and they differ in how this demand rate is estimated. An extensive numerical study shows improved accuracy compared to existing methods with similar computational complexity. The numerical study also shows that the batch quantities and the service level have a large influence on the delay. Both the mean and variance of a retailer’s delay decrease with the service level and increase with the batch quantities used at the warehouse and at the retailer. No other variables seem to have a significant impact on the delay.
The discounted continuous-review (R,Q) inventory model with continuous and stochastic demand is investigated. New optimality conditions are derived, clarifying the difference to the average cost case, also graphically. Supported by depreciation theory, applied to the value of a setup, the results suggest an insightful and very precise approximation – The Shrewd Accountant’s Heuristic – based on a new average-cost model. It deepens and extends the work of Hadley (1964). Three examples are worked out in detail and the model is generalized to Poisson demand and to stochastic lead-times.
This paper describes how a common database can play an important role in reaching cost-effective improvements of maintenance performance. The definition and overall design of a common database are presented and illustrated by a case. The main result presented is that it is possible to access a more correct view of the situation in the production by data (information) integration and thereby obtain a better base for making maintenance decisions. The common database supports the development of applications e.g. for monitoring the performance of a production process, for deciding the most cost-effective maintenance policy or for simulating possible maintenance solutions.