The presentation of information in the maintenance and repair manual. Lift cost analysis process during operation and maintenance period. Principal factors affecting maintainability. Maintainability prediction is the estimation of maintenance workload (preventive and corrective) associated with the proposed design. 3. The factors which affect the frequency with which ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. URL:, URL:, URL:, URL:, URL:, URL:, URL:, URL:, URL:, URL:, Product Development (Second Edition), 2014, G.W.A. Availability is the possibility of access to a system for normal operation at a given moment when available. The difference between those two indexes means that throughout part of the operational time the distillation unit production was not 100%. Maintainability depends on the product design and the technical level of repair personnel, the repair process, and the repair facilities. Soumi Ghosh, Sanjay Kumar Dubey and Ajay Rana, Update/Correction/Removal In the breakdown of periodic maintenance, as shown in Figure 14.49, it can be seen that most costs are incurred on periodic replacement, inspection, and adjustment, while the rest is for tamping, grinding, and reconditioning of welding heads. Factors affecting computer performance Date Posted: 10/24/2012 3:25:45 AM. The simulation was conducted for 5 years and 250 tests were run to converge results. In pharmacokinetics, bioavailability is related to absorption and is the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. 7. Ways to improve equipment maintainability. Suppose that Tm is the repair time with repair density function m(t). The three main components of equipment downtime are logistic time, administrative time, and active repair time [20]. All in all, since active repair time is largely determined by the equipment's built-in maintainability characteristics, the manufacturer of the equipment plays a key role in influencing how much active repair time is required. Composition of turnout cycle maintenance cost. Apart from the fact that replacement parts needs are affected by factors such as operating conditions and the equipment's inherent capability to tolerate operating stress levels, logistic time is largely a matter of management. The two parameters are somewhat correlated, as shown in Table 14.12. Its purpose is to measure the probability that a piece of equipment in a failed state can be restored to normal operating conditions after undergoing maintenance. Required administrative activities and unnecessarily wasted time are both included in administrative time. The user may supervise and manage the supplier by specifying compulsory RAMS work content in the procurement agreement for turnouts, so as to ensure the implementation of relevant quantitative and qualitative requirements for RAMS during the process of R&D and production of the products. Pr… Figure 8-2. Take the life cycle of turnout products, for instance; the relationships among RAMS parameters are shown in Table 14.10. The discipline’s first concerns were electronic and mechanical components (Ebeling, 2010). Equipment downtime components. AU - Hordijk, W.T.B. metric that measures the probability that a system is not failed or undergoing a repair action when it needs to be used A Survey of Key Factors Affecting Software Maintainability. This could be caused by a number of factors. Previous Chapter Next Chapter. Also patching update mechanisms could be implemented to improve the overall performance of the system during runtime, these mechanisms are often referred to as live upgrade or live update mechanisms. The comprehensive assessment of the costs for product procurement and use, etc. Maintainability is the measure of the ability of an item to be retained in or restored to a specified condition when maintenance is performed by personnel having specified skill levels using prescribed procedures and resources at each prescribed level of maintenance and repair. Y1 - 2005. The selection of best maintainability model is prime concern for developing quality software system. The concept of LCC originated from the Swedish railway system; operational and maintenance cost of turnouts is assessed with LCC technology by taking Swedish railway turnouts as an example. From: Product Development (Second Edition), 2014, G.W.A. Figure 1-1. Administrative time is that portion of equipment downtime not taken into consideration in active repair time and in logistic time. There are many components of investment cost related to maintainability. Flexibility is the ability of software to add/modify/remove functionality without damaging the current system. You may be wondering why you computer is slow at times and there are other times when it is fast in processing. Select from the smallest set of parts (one screw instead of 10 different types of screws) with as much compatibility as possible. For these metrics, the average per module is taken, and combined into a single formula: To arrive at this for… Using the container virtualization in data-centric systems offers us high level maintainability due to the nature of containerization technologies. Maintainability documentation consists of tasks such as developing maintainability data and feedback reports, establishing and maintaining a maintainability data bank and a library containing important maintainability documents and information, documenting information related to maintainability management, preparing and maintaining handbook data and information with respect to maintainability, documenting maintainability trade-offs and the results of maintainability analysis, and documenting the results of maintainability design reviews. Therefore, the selection of reliability and maintainability of the equipment should try to minimize the total cost of procurement and maintenance, that is, LCC, if other conditions are the same. Reliability was first practiced in the early start-up days for the National Aeronautics and Space Administration (NASA) when Robert Lusser, working with Dr. Wernher von Braun's rocketry program, developed what is known as \"Lusser's Law\" . Operational reliability defines the performance level of intrinsic reliability of a product in actual use. Classification and evaluation criteria for different Reliability, Availability, Maintainability, Safety, and Inspectability (RAMS + I) factors are outlined and discussed. As per EN50126-1 and EN50126-3, RAM parameters may be separated from safety parameters in the railway transport industry. The simulation creates typical life cycle scenarios for proposed systems, with Monte Carlo simulation methodology. The RAMS/LCC assessment model is to assess the equipment systems by efficiency and LCC. Designing for Maintainability: Human Factors Considerations. EV-UIC60-760-1:15: No. Open menu. As the system design progresses to the detailed level, more complete design information becomes available and consequently estimation of system maintainability characteristics becomes more accurate. These include, as shown in Figure 8-2, the costs of prime equipment, system engineering management, repair parts, support equipment, data, training, system test and evaluation, and new operational facilities [2]. This shows that, in some examples, equipment failures do not represent total plant shutdown. Petar Kochovski, Vlado Stankovski, in Security and Resilience in Intelligent Data-Centric Systems and Communication Networks, 2018. Safety refers to the capacity of a system or product to prevent personal injury, system destruction, or major property loss, and to avoid hazard to people and the environment. However, they are particularly pertinent in programs where risks are high or unknown, and failing to achieve the maintainability requirements, highly undesirable. Asset availability is impacted by several factors. AB - In the offshore wind energy sector, there are many different conceptual wind turbine structures, from traditional mono-pile structures to floating platforms. and Jisc. Specifically: Figure 14.50. For example, a more maintainable product lowers maintenance time and operating costs. Linguee. This mode places more importance on operational safety of the track components than economical efficiency. Here is a list of human factors related, design for maintainability considerations: Consider maintenance from ‘cradle to grave’. Figure 14.49. The maintainability effort produces and uses a significant amount of information and data. It is a blend of several metrics, including Halstead’s Volume (HV), McCabe’s cylcomatic complexity (CC), lines of code(LOC), and percentage of comments (COM). The actual techniques used to optimize system effectiveness will be described in greater detail elsewhere in this blog. This paper presents different maintainability models from various standards and quality models define its sub-characteristics and then perform analytical comparison of these sub-characteristics. Target Reliability of System Levels. Maintainability is the ability of the system to undergo modifications with a degree of ease. Each factor is described by a … Maintainability can be defined as “the degree of facility with which an equipment or system is capable of being retained in, or restored to, serviceable operation. Examines the factors that affect the maintainability of a software. define a system’sinherent maintainability and thus determine the related maintenance burden and affect system availability. The entire unit was modeled through RBDs, considering the redundancies and the possibilities for bypass in each equipment or system configuration. However, in the face of marketization reform of the Chinese railway management system and huge debts from HSR construction, the managers of the railway infrastructure had to find a way out, and attempted to reduce the cost of rail components, optimizing railway engineering maintenance technology based on reliability and guided by risk-informative safety management, so as to minimize the costs of engineering operation and maintenance while maintaining a certain safety level. Request. Figure 14.48. 1.2.3 Maintainability Maintainability is the ability of an item to be retained in, or restored to, a specified condition when maintenance is performed by personnel having specified skill levels, using prescribed procedures and resources, at each prescribed level of maintenance and repair. Suggest as a translation of "maintainability factors" Copy; DeepL Translator Linguee. Operator error is the second-most common cause of downtimeafter hardware error. structure, complexity.- Each factor (or group of factors) should be assigned a weighting to indicate its importance to the overall maintainability of the system. Product revision factors− Maintainability, Flexibility, Testability. Table 14.11 presents the basic RAM parameters of high-speed turnouts. Today software quality is a major point of concern and it is important to be able to assess the maintainability of a software system. RAMS is an acronym for “reliability, availability, maintainability, and safety.” In Europe, EN 50126 has long prevailed in the railway industry; this code was defined as IEC 62278: 2002 and later. (b) The positioning of maintenance displays, check points, gauges, meters and the position of one assembly with respect to others.
2020 factors affecting maintainability