In this paper we discuss the problems associated with the description and manipulation of large systems when their sources are not maintained as single fields. We show why and how tools that address these issues, such as Unix MAKE and Lisp Machine DEFSYSTEM, have evolved. Existing formalisms suffer from the problem that their syntax is not easily separable from their functionality. In programming languages, standard "calling conventions" exist to insulate the caller of a function from the syntactic details of how that function was defined, but until now no such conventions have existed to hide consumers of program systems from the details of how those systems were specified. We propose a low-level data abstraction which can support notations such as those used by MAKE and DEFSYSTEM without requiring that the introduction of a new notation be accompanied by a completely different set of tools for instantiating or otherwise manipulating the resulting system. Lisp is used for presentation, bit the issues are not idiosyncratic to LISP.

Management decisions in complex industrial facilities usually consider both the economic and environmental aspects of the plant's performance. For nuclear power plants (NPPs), safety is also a very substantial issue. The objectives of this dissertation are to develop and demonstrate a novel useful conceptual model that could be used to allocate maintenance funds for a nuclear power plant in such a way as to meet all specified safety requirements and objectives, while achieving a high degree of economic performance. The model is based on the general theory that the reliability of a plant at any time is a function of its initial reliability and the maintenance history of the individual plant components (Smith, 1997). Such a model can assist in evaluating strategic management decisions regarding allocation of funds for nuclear power plant maintenance. It could be used as a simulation tool; various scenarios could be studied to answer "what if" questions. Simulations of this type will allow a better understanding of the relationship between maintenance, economic performance, and safety, and consequently will lead to better decision making. The novelty of this model is tied to the intimate relationship that it develops between maintenance activities at a nuclear plant, and their relationship to prescribed safety requirements and to the economic performance of that plant.

Maintenance is one area of business that recently has been considered as an activity contributing efficiently to the companies' strategic goals. Understanding the way maintenance could utilise modern technology such as computerised tools or digital data processing is one way to make maintenance profitable. Current research lack appropriate methods for determining data and IT requirements, as well as understanding the way IT could be utilised for enhancing maintenance profitability. This thesis studies and develops tools, methods and theories of how information technology can be utilised for maintenance management in order to reach profitable maintenance. The main research problem is therefore: What are the demands on information technology systems to achieve profitable maintenance? The main problem has been divided into three research questions: RQ1) What are the demands on data and information technology systems for strategic management of maintenance?, RQ2) How can we identify relevant data and information technology systems required to achieve cost-effective maintenance decisions? and RQ3) How can we describe the utilisation of information technology within maintenance? This thesis is based on a systems theory approach, where maintenance is not seen as an isolated activity, but something that interacts, affects and is affected by several other activities, such as production, logistic and quality. Several methods have been used for answering the research questions, but the theory-testing case study method dominates. Main results achieved in the thesis are models and theory for 1) creating a relevant set of data for cost-effective mainte-nance decisions, 2) monitoring the performance of maintenance, suggest invest-ment possibilities and show maintenance contribution on company strategic level, 3) identifying IT systems requirements demanded to achieve profitable maintenance and 4) assessing the IT maturity of a maintenance organisation for the effective utilisation of IT systems. As an illustrative example of computerised maintenance management demands a conceptual decision support model has been developed, which aims at filling the gaps of poor IT coverage for strategic maintenance decision-making. This thesis concludes that the demands of data and IT applications must be connected to the overall maintenance demands, which are reflected in the maintenance goals, purposes and strategy, in order to achieve profitable maintenance. Furthermore, structured methods that ensure the connection between maintenance business goals and data or IT demands are of importance. The ability to make use if IT within maintenance is reflected in the relative IT maturity of the maintenance organisation. Being able to define the IT maturity allows for choosing the most appropriate IT tool to invest in, so that current and future needs of IT support are also covered for with maximum benefit and minimum cost.

In this study the reader will learn how to work with student adaptation as a method for students to easier study and learn mathematics at a vocational school focusing on vehicle maintenance. This secondary school is located in the southern part of Sweden. Four math teachers who teach at this program use in-depth interview when it comes into explaining what they mean regarding adaptation and its role in teaching this students and helping them pass the course. This is very much a topic of today and has been so for some time. We hear about reports which reveals alarmingly low levels of know light which continue to drop especially at vocational programs in particular in mathematic. The math teachers describe specific obstacles and circumstances which in their experiences will limit their teaching options and alternatives and therefore will also limit the adaptation and its role. One may say in general that adaptation not necessarily is a method with an obvious template to follow so many various players will have to be involved in the teaching. This holds true with regards to all various aspects of learning. The student is here by enabled to see and experience the full picture of the program and the subject in question. No matter what the subject is, focus will always be the goal of the program and the students’ future careers. There are questions as to whether there may be conflicts of interest between the various actors involved in the learning process. .

Despite the fact that a handover process is just as frequently performed as any development process, little is known about it. Still, it is regarded as one of the lifecycle processes that is not well explored and defined. In this paper, we study the handover process within eighteen companies with the purpose of demarcating its scope within software lifecycle. Our goal is to find out how industry understands handover process and how it places it within software lifecycle. As a result, we have identified seven different scope contexts for the handover process. We have also provided evidence of its wide lifecycle span and its overlap with development, predelivery and postdelivery maintenance processes. / © 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Qc 20120223

Even if a handover process is a critical stage in the software lifecycle, little is known about the problems encountered when transferring a software system from development to maintenance. In this paper, we have elicited five core handover problems as faced by five IT organizations today. These are (1) insufficient system knowledge, (2) lack of domain knowledge, (3) insufficient communication, (4) inadequate documentation, and (5) difficulties in tracking changes. / QC 20120223

Today, maintenance is a big part of the daily life on board ships. It is also one of the bigger expenses a shipping company has and without any loss of quality tries to run as economically advantageous as possible. In the hunt for economical savings the shore-based industry has subsequently applied the use of condition based maintenance, CBM, were a component is maintained according to its actual state. This leads to a reduction of maintenance costs since no parts are unnecessarily replaced. However, within the maritime sector a periodical maintenance is still the most commonly used maintenance system.The purpose of this paper is to chart the factors that are the reason for the low implementation of CBM on board the Swedish merchant fleet's ships. The investigation was carried out according to the qualitative method. Three shipping companies were interviewed, all carrying slow speed, two-stroke crosshead engines.The result from the interviews were evaluated and analyzed and the contributing factors of the low implementation of CBM on board has been identified.The result of this paper shows that the unique conditions on board ships reduces the advantages, normally received in the shore-based industry by using CBM. / Underhåll är en stor del av vardagen till sjöss. Det är även en av de stora utgiftsposterna för ett rederi och utan att tumma på kvaliteten vill man bedriva detta så ekonomiskt fördelaktigt som möjligt. I jakten på besparingar har den landbaserade industrin mer och mer övergått till ett tillståndsbaserat underhåll, s.k. condition based maintenance - CBM. Då bedrivs underhållet utifrån en komponents faktiska tillstånd. Detta leder till minskade underhållskostnader eftersom komponenter inte utbytes i onödan. Inom sjöfarten är dock det periodiskt baserade underhållet fortfarande dominerande.Syftet med denna undersökning är att kartlägga de faktorer som ligger till grund för den ringa utsträckningen av tillståndsbaserat underhåll, CBM på den Svenska handelsflottans fartyg. Undersökningen utfördes enligt den kvalitativa metoden. Tre rederier intervjuades, samtliga med fartyg i oceantrafik där framdrivningsmaskineriet består av långsamtgående, 2-takts tvärstycksmaskiner. Intervjuerna utvärderades och analyserades varpå de bidragande faktorerna till den begränsade användningen identifierades.Resultatet av undersökningen visar på att de unika förutsättningar som råder på ett fartyg minskar fördelarna, som man normalt erhåller med CBM inom den landbaserade industrin.

The maintenance of large-scale software systems without trace information between development artifacts is a challenging task. This thesis focuses on the problem of supporting software maintenance through a mechanism for establishing traceability relations between the system requirements and its code elements. The core of the proposed solution is a set of design rules that regulates the positional (e.g., package), structural (e.g., class), and behavioral (e.g., method) aspects of the system elements, thus establishing traceability between requirements and code. We identify several types of requirements each of which can be supported by design rules. We introduce a rule-based approach to software construction and demonstrate that such a process can support maintainability through two mechanisms: (a) traceability and (b) reduction of defect rate. We distinguish our work from traditional traceability approaches in that we regard traceability as an intrinsic structural property of software systems. This view of traceability is in contrast to traditional traceability approaches where traceability is achieved extrinsically through creating maps such as the traceability matrices or allocation tables. The approach presented in this thesis has been evaluated through conducting several empirical studies as well as building a proof-of-concept system. The results we obtained demonstrate the effectiveness and usefulness of our approach.

Deregulated and competitive power market places utilities under high pressure to assure providing power with a satisfactory level of power continuity. This objective entails a high level of reliability which in turn demands a high financial budget for design, operation, and maintenance. Therefore, the need for utilities to balance these factors has been increasing to become the core of a utility's asset management activities. Maintenance is a key aspect of asset management. The main objective of maintenance is to extend the lifetime of equipment and/or reduce the probability of failure. Maintenance activities play an important role in improving system reliability by keeping the condition of a system's equipment within an acceptable level. Generally speaking, technical requirements and budget constraints are the most influential factors in assigning maintenance activities. The most cost-effective maintenance approach is the approach that can sustain a high level of reliability while maintenance cost is minimized. The transformer has a significant role in the power system due to its remarkable effect on the overall level of reliability in addition to its extensive investments in the power grid. Transformer management is comprised of identifying the appropriate type and frequency to maintain the transformer, and the appropriate time to replace the transformer in a cost-effective manner. The essential objective of this thesis is to introduce a novel framework for transformer management. An approach which links maintenance and replacement decisions is presented in this thesis. This approach proposes a methodical decision-making system to determine the optimal time to replace the transformer. Indeed, the proposed approach essentially investigates the cost-effectiveness of replacing the transformer both before and after the lifetime is extended by maintenance. To properly investigate the effect of maintenance, maintenance activities should first be scheduled effectively. Therefore, this approach introduces a maintenance strategy based on reliability-centered maintenance (RCM) concept and genetic algorithm (GA) to optimally schedule maintenance activities. Two replacement studies are conducted: with and without the effect of maintenance. A comparison between replacement studies is discussed in the proposed approach.

Recognition of maintenance management as a significant factor holds the key to competitiveness in the global market irrespective of the size of the business. Maintenance management practices are primarily found in larger and multinational companies but the purpose of this paper is to investigate the maintenance practices that are used in SMEs of Sweden (Kronoberg County). The study is expected to expose the level of maintenance perception in the Swedish industry via a postal (and web based) questionnaire. The survey covered 74 company chosen from different sectors and produced a response rate of 20.3 percent. The main results achieved from the study show us difference between the maintenance perception and awareness of the maintenance. The respondents are aware of the importance of maintenance, but maintenance is still perceived as a necessary expense. Because according to the results of the survey the percentage of maintenance budget in comparison to the companies’ turnover is on average about 0.97% and it is very low. Again, when we look at the maintenance cost distribution of companies, spare parts and labour costs consist of 73 % of total maintenance cost, despite that they spend very little money for technology and training costs, their percentages in total cost are just 3% and 2%, also they still ignore statistical modelling (historical data) and condition monitoring. Moreover, just 27% of the participants use the maintenance key performance indicators (KPIs), and just 14% of them used basic KPIs which are used for measuring maintenance performance. There is a need to spend and invest more in maintenance especially they should invest more in technology and training to perform them. On the other hand, there is a need for choosing right maintenance strategy and service type, because these points are very important for an effective and economic maintenance management.