Tesi sul tema "Maintainability model"

Web applications incorporate important business assets and offer a convenient way for businesses to promote their services through the internet. Many of these web applica- tions have evolved from simple HTML pages to complex applications that have a high maintenance cost. This is due to the inherent characteristics of web applications, to the fast internet evolution and to the pressing market which imposes short development cycles and frequent modifications. In order to control the maintenance cost, quantita- tive metrics and models for predicting web applications’ maintainability must be used. Maintainability metrics and models can be useful for predicting maintenance cost, risky components and can help in assessing and choosing between different software artifacts. Since, web applications are different from traditional software systems, models and met- rics for traditional systems can not be applied with confidence to web applications. Web applications have special features such as hypertext structure, dynamic code generation and heterogenousity that can not be captured by traditional and object-oriented metrics. This research explores empirically the relationships between new UML design met- rics based on Conallen’s extension for web applications and maintainability. UML web design metrics are used to gauge whether the maintainability of a system can be im- proved by comparing and correlating the results with different measures of maintain- ability. We studied the relationship between our UML metrics and the following main- tainability measures: Understandability Time (the time spent on understanding the soft- ware artifact in order to complete the questionnaire), Modifiability Time(the time spent on identifying places for modification and making those modifications on the software artifact), LOC (absolute net value of the total number of lines added and deleted for com- ponents in a class diagram), and nRev (total number of revisions for components in a class diagram). Our results gave an indication that there is a possibility for a relationship to exist between our metrics and modifiability time. However, the results did not show statistical significance on the effect of the metrics on understandability time. Our results showed that there is a relationship between our metrics and LOC(Lines of Code). We found that the following metrics NAssoc, NClientScriptsComp, NServerScriptsComp, and CoupEntropy explained the effort measured by LOC(Lines of Code). We found that NC, and CoupEntropy metrics explained the effort measured by nRev(Number of Revi- sions). Our results give a first indication of the usefulness of the UML design metrics, they show that there is a reasonable chance that useful prediction models can be built from early UML design metrics.

A model is developed for use by logistics planners in determining period by period maintenance requirements for repairable item populations. The model generates maintenance requirements with respect to manpower and facility requirements and spare parts requirements. The model is capable of capturing nonsteady-state failure behavior of populations of repairable items. Each item within the population is broken down into one or more families of components and subcomponents that can have different failure/repair characteristics. Probability of component failure may be generally distributed. A specific data requirement for the model is established. The model is structured to allow the user to conduct various"what if gaming" through an iterative procedure on a personal computer. This research document includes a literature review that establishes a history of logistics modeling. The literature review provides impetus to the proposed research by defining a need for a transient state model for maintenance requirements planning. The model is validated by a case study involving the generation of maintenance requirements for a case population.
Master of Science

Companies are under constant pressure to adapt and improve their processes to staycompetitive. Since most of their processes are handled by software, it also needs toconstantly change. Those improvements and changes add up over time and increase thecomplexity of the system, which in turn prevents the company from further adaption.In order to change and improve existing business processes and their implementation withinsoftware, several stakeholders have to go through a long process. Current IT methodologies arenot suitable for such a dynamic environment. The analysis of this change process shows thatfour software characteristics are important to speed it up. They are: transparency, adaptability,testability and reparability. Transparency refers to the users capability to understand what thesystem is doing, where and why. Adaptability is a mainly technical characteristic that indicatesthe capability of the system to evolve or change. Testability allows automated testing andvalidation for correctness without requiring manual checks. The last characteristic is reparability,which describes the possibility to bring the system back into a consistent and correct state, evenif erroneous software was deployed.An architecture and software development patterns are evaluated to build an overall programmingmodel that provides the software characteristics. The overall architecture is basedon microservices, which facilitates decoupling and maintainability for the software as well asorganizations. Command Query Responsibility Segregation decouples read from write operationsand makes data changes explicit. With Event Sourcing, the system stores not only the currentstate, but all historic events. It provides a built-in audit trail and is able to reproduce differentscenarios for troubleshooting and testing.A demo process is defined and implemented within multiple prototypes. The design of theprototype is based on the programming model. It is built in Javascript and implements Microservices,CQRS and Event Sourcing. The prototypes show and validate how the programmingmodel provides the software characteristics. Software built with the programming model allowscompanies to iterate faster at scale. Since the programming model is suited for complex processes,the main limitation is that the validation is based on a demo process that is simpler and thebenefits are hard to quantify.
ör att fortsatt vara konkurrenskraftiga är företag under konstant press att anpassa ochförbättra sina processer. Eftersom de flesta processer hanteras av programvara, behöveräven de ständigt förändras. Övertiden leder dessa förbättringar och förändringar till ökadsystemkomplexitet, vilket i sin tur hindrar företaget från ytterligare anpassningar. För attförändra och förbättra befintliga affärsprocesser och dess programvara, måste idag typiskt fleraaktörer vara en del av en lång och tidskrävande process. Nuvarande metoder är inte lämpade fören sådan dynamisk miljö. Detta arbete har fokuserat på fyra programvaruegenskaper som ärviktiga för att underlätta förändringsprocesser. Dessa fyra egenskaper är: öppenhet, anpassningsförmåga,testbarhet och reparerbarhet. Öppenhet, hänvisar till förmågan att förstå varför, var ochvad systemet gör. Anpassningsbarhet är huvudsakligen en teknisk egenskap som fokuserar påsystemets förmåga att utvecklas och förändras. Testbarhet strävar efter automatisk testning ochvalidering av korrekthet som kräver ingen eller lite manuell kontroll. Den sista egenskapen ärreparerbarhet, som beskriver möjligheten att återhämta systemet till ett konsekvent och korrekttillstånd, även om felaktig programvara har använts. En programmeringsmodell som rustarprogramvara med de ovan beskrivna programegenskaperna är utvecklad i detta examensarbete.Programmeringsmodellens arkitektur är baserad på diverse micro-tjänster, vilka ger brafrånkopplings- och underhållsförmåga för en programvara, samt användarorganisationerna.Command Query Responsibility Segregation (CQRS) frånkopplar läsoperationer från skrivoperationeroch gör ändringar i data explicita. Med Event Sourcing lagrar systemet inte endastdet nuvarande tillståndet, utan alla historiska händelser. Modellen förser användarna medett inbyggt revisionsspår och kan reproducera olika scenarion för felsökning och testning. Endemoprocess är definierad och implementerad i tre olika prototyper. Designen av prototypernaär baserad på den föreslagna programmeringsmodellen. Vilken är byggd i Javascript och implementerarmicro-tjänster, CQRS och Event Sourcing. Prototyperna visar och validerar hurprogrammeringsmodellen ger programvaran rätt egenskaper. Programvara byggd med dennaprogrammeringsmodell tillåter företag att iterera snabbare. De huvudsakliga begränsningarna iarbetet är att valideringen är baserad på en enklare demoprocess och att dess fördelar är svåraatt kvantifiera.

This thesis studies the use of the functional reactive programming (FRP) framework reactive-banana in a prototype which simulates a part of a Long-Term Evolution (LTE) base station: the Radio Resource Control connection setup procedure. The investigated problem is to determine whether using this FRP framework leads to an implementation with suitable performance and improved maintainability compared to the current implementation. Enhancing the maintainability of the base station software enables quicker and more efficient maintenance activities, which lead to an improved customer satisfaction. Moreover, it means that less programmers need to work on maintenance, so they can work on developing new products instead. In order to compare the use of the FRP paradigm to the one currently used in the base station implementation, the object-oriented programming (OOP) paradigm, a second prototype using this paradigm was also implemented. Having two prototypes implementing the same designed reference model (which is a simplified version of the Radio Resource Control connection setup procedure) enables a relevant comparison of the two paradigms. The two prototypes were then compared in terms of performance and maintainability. The maintainability evaluation consisted in using both software metrics and experts’ assessment, as this has been proven to be the most efficient way to evaluate software maintainability. Four experts were asked to fill in a questionnaire after reviewing the code of the two implementations. The comparison of the two prototypes indicates that the FRP prototype is more maintainable than the OOP one, but the OOP prototype has better performances than the FRP one. Moreover, the performance of the FRP prototype during the conducted tests indicates that such an implementation of the FRP paradigm is not suitable for a real base station.

Le coût élevé de la maintenance des logiciels exige de travailler sur leur maintenabilité. Bien qu’émergente de la structure du code source, son évaluation est subjective, car elle dépend des développeurs et du contexte. Les modèles de maintenabilité actuels tendent à réduire la maintenabilité à un score unidimensionnel basé sur des métriques, souvent mal définies, qui représentent mal la structure du code. Nos travaux se sont basés sur l’analyse statique des graphes de code pour évaluer la maintenabilité. Ils ont permis de développer Javanalyser, un outil libre qui génère automatiquement le graphe de code d’un programme Java. Ces graphes ont permis de formaliser 33 métriques statiques sous forme de requêtes déclarative et ont permis de reproduire avec succès une étude de Schnappinger et al. Notre extension de l’étude confirme l’importance de la taille du programme comme facteur influençant la maintenabilité, sans toutefois négliger l’impact des autres métriques. Ce travail ouvre la voie à une compréhension plus approfondie de la maintenabilité, grâce à une représentation multidimensionnelle permettant de tenir compte de la variabilité entre les développeurs
The high cost of software maintenance requires a focus on software maintainability. Although it emerges from the structure of the source code, its evaluation is subjective, as it depends on developers and the context. Current maintainability models tend to reduce maintainability to a one-dimensional score based on metrics, often poorly defined, which inadequately represent the structure of the code. Our work is based on the static analysis of code graphs to evaluate maintainability. It led to the development of Javanalyser, an open-source tool that automatically generates the code graph of a Java program. These graphs enabled the formalization of 33 static metrics as declarative queries, and allowed the successful replication of a study by Schnappinger et al. Our extension of the study confirmed the importance of size as a factor influencing maintainability, while also recognizing the impact of other metrics. This work opens the way to a deeper understanding of maintainability through a multidimensional representation that takes into account the variability between developers

This project examines how the quality of a code generator used in an Object-Relational Mapping (ORM) framework can be improved in terms of maintainability, testability and reusability by changing the design from a top-down perspective to a bottom up. The resulting generator is tested in a case study to verify that the new design is more cohesive and less coupled than an existing code generator.

O transporte aéreo e a indústria de sistemas de defesa foram setores pioneiros na utilização de sistemas computacionais críticos, incrementando os níveis de automação nas atividades de controle do espaço aéreo. Com o crescimento desses setores, verificado pela expansão dos números de vôos, volumes de cargas e usuários, assim como pela ampliação e diversidade das operações militares, os sistemas de controle têm assumido maior complexidade técnica, introduzindo novos recursos de automação ou facilidades adicionais de apoio para funções exercidas manualmente. Essa situação tem ampliado a dependência dos serviços prestados, relativamente à disponibilidade dos sistemas computacionais. Diretrizes de projeto e procedimentos operacionais são estabelecidos para manter os níveis de segurança nos casos de falha, no entanto a disponibilidade torna-se parâmetro crítico, na medida em que algumas falhas podem afetar a eficiência nominal da prestação dos serviços. Nesse cenário, este trabalho propõe um modelo para avaliação da disponibilidade de sistemas de controle do espaço aéreo, a partir de recursos de análises da teoria de filas. Inicialmente é citado um modelo geral para análise de disponibilidade de data centers. Em seguida, é apresentada uma extensão do modelo geral para análise da disponibilidade em sistemas de controle do espaço aéreo. Para isso, considerou-se a intervenção humana existente nessa atividade, cujas decisões de controle são exercidas por operadores qualificados (controladores), tanto nas atividades inerentes ao serviço de controle, quanto nos casos de degradação, nos quais os operadores ou técnicos de manutenção assumem alguma tarefa de reparo, decorrente da eventual indisponibilidade de funções do sistema.
Due to the growth in airspace utilization, which can be verified both in terms of the expansions in aerial movements, airports and volumes of transported passengers and cargo, as well as in terms of the expansion of military operations demands and diversity, airspace control activities have been increasing their technical complexity, introducing new features into the existent automation systems or creating additional resources for the automation of some functions previously performed by human operators. This situation has increased the dependence on the availability of the computer systems involved in the services provided by control centers. Project directives and operational procedures are established in order to maintain the safety integrity levels of the systems, in case any failure occurs. However, the availability becomes a critical parameter, once failure events can force an undesirable state of degraded operation, jeopardizing the nominal capacity of the services being performed through any controlled airspace. In this scenario, this work presents an availability model for the computer systems used in airspace control centers, based on analysis from queuing theory. A general model is first presented, referencing a case study that describes the use of queuing models to access the availability of generic data centers. Further considerations are introduced to extend this general model in order to propose its application for the specific computer systems used in airspace control centers, where operational control relies on human activities. In this case, system operation involves intensive use of human-machine interfaces (HMI), for the regular control services provided, and additional technical or operational maintenance activities, occasionally imposed to repair a momentary loss of any function of the system.

Organizations are expected by their shareholders to continually deliver above industry returns on capital invested and to remain competitive in the industry of choice through productivity, safety and quality. The maintenance function is a key area in which competitiveness through efficiencies and world–class performance can be attained by focusing on the prevention and reduction of long and costly equipment repair times. The question is: how can the mean time to repair of equipment already installed in the plant be reduced? To answer the above question correctly and comprehensively, the research explored mixed methods in finding answers. Quantitative methodology using a survey was used for data collection. Observations and interviews were held with maintenance personnel to uncover information that couldn’t have been obtained by means of a survey. The survey was limited to equipment performance measures, human factors, environmental factors, planning, spare parts, maintainability, procedures and training. To test consistency and accuracy of representation of the total population under study, a reliability test was done by using Cronbach’s alpha coefficient. To determine whether there are any differences between groups, an ANOVA test was used. Cohen’s d–value was used to determine practically significant differences between one set of data with another and correlation analysis was used to determine the relationships between the variables. The approach designed and delivered by this research flowed from the existing body of knowledge, case studies and survey findings. The approach adopts some of the elements of the failure mode and effects analysis (FMEA) procedure and differs from other work that has been done by others by taking into account the competency and experience of maintenance personnel and assigning to them factors which are used to compute anew MTTR of the equipment. The cost of implementing the recommended corrective actions for realising the new MTTR is determined and evaluated against an improved equipment availability that will be achieved as a result of the recommended corrective actions assuming that the failure rate of the equipment remains constant. This evaluation step imbedded within the approach is valuable for the maintenance function and management for decision making in ensuring that resources at the organization’s disposal are used productively. Validation and test results of the approach showed that the MTTR of equipment installed in the plant can be reduced. The results also indicated that through the use of the designed approach a regular pattern of repair or replacement times can be followed well in advance and that it is practical, user friendly and it also delivers on its objective of offering a structure for analysis and decision making aimed at reducing the MTTR. Included with this dissertation is feedback information that can be included in a maintenance job card feedback section to capture information about factors that can be improved to lower the MTTR as part of a continuous improvement process. Included also is a spare part development and management procedure that can be used by the maintenance function. Recommendations on training of maintenance personnel on the maintainability of equipment, the FMEA procedure and maintenance procedures are highlighted. Information that flowed from this approach will be valuable for continuous plant performance improvement and during the design, installation and operation stages of a blast furnace.
Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2012.

La sûreté de fonctionnement (SdF) est devenue une nécessité dans le monde industriel au cours du XXe siècle. La SdF est un domaine d’activité qui propose des moyens d’augmenter les attributs du système dans un délai raisonnable et à moindre coût. Dans l’ingénierie des systèmes, la SdF est définie comme la propriété qui permet aux utilisateurs du système de placer une confiance justifiée dans le service qu’il leur fournit et c’est une mesure de la disponibilité, de la fiabilité et de la maintenabilité d’un système, et de la performance du support de maintenance, et, dans certains cas, d’autres caractéristiques telles que la durabilité, la sûreté et la sécurité. Le concept sur lequel notre travail est basé est la textbf disponibilité. La disponibilité A(t) est la capacité d’un système à être opérationnel à un moment précis. Le coût d’un système à haute disponibilité est très cher. Le concepteur doit faire un compromis entre la disponibilité et les coûts économiques. Les utilisateurs peuvent rejeter des systèmes dangereux, peu fiables ou non sécurisés. Par conséquent, tout utilisateur (ou industrie) posera cette question avant avoir un produit : "Quel est le produit optimal sur le marché ?" Pour répondre à cette question, nous devons combiner les deux points suivants : - La meilleure disponibilité du système : l’utilisateur souhaite un produit qui dure longtemps le plus possible. - Le meilleur coût du système : l’utilisateur veut un produit sans lui coûter une fortune. Le calcul de la disponibilité est basé principalement sur la connaissance des taux de défaillance et des réparations des composants du système. L’analyse de disponibilité permet de calculer la capacité d’un système à fournir un niveau de performance requis en fonction du niveau de dégradation. Plusieurs méthodes ont été utilisées pour calculer la disponibilité d’un système, parmi lesquelles on trouve la Fonction de Génératrice Universelle (UGF), la technique d’inclusion-exclusion, les modèles de Markov, etc. Ces méthodes utilisent différentes techniques probabilistes pour évaluer ce critère, mais ces approches proposées ne restent efficaces que pour des cas très spécifiques, par exemple les cas de systèmes binaires. Un système binaire est un système où deux cas sont possibles : fonctionnement parfait et défaillance totale. Alors que les systèmes multi-états (SME) restreint considérablement l’application de la plupart de ces méthodes. Dans la vie réelle, les systèmes correspondent à des SME. Dans de tels scénarios, les systèmes et leurs composants peuvent fonctionner à différents niveaux de performances entre l’état de fonctionnement parfait et l’état de défaillance totale. Cependant, l’évaluation de la disponibilité des SME est plus difficile que dans le cas binaire, car il faut tenir compte des différentes combinaisons des modes de défaillance des composants. Tout au long de cette thèse, nous recherchons une méthode qui nous aide à calculer et à optimiser la disponibilité de SME tenant compte le facteur coût
Dependability has become a necessity in the industrial world during the twentieth century. Dependability is an activity domain that proposes means to increase the attributes of the system in a reasonable time and with a less cost. In systems engineering, dependability is defined as the property that enables system users to place a justified confidence in the service it delivers to them and it is a measure of a system’s availability, reliability, and its maintainability, and maintenance support performance, and, in some cases, other characteristics such as durability, safety and security. The key concept that our work is based on is the availability. The availability A(t) is the ability of a system to be operational at a specific moment. The cost of some system with high availability is very expensive. The designer must compromise between the availability and the economic costs. Users can reject systems that are unsafe, unreliable or insecure. Therefore, any user (or industry) will ask this questionbefore getting any product: "What is the optimal product in the market?" To answer to this question, we must combine the following two points : - The best availability of the system : the user wants a product that lasts as long as possible. - The best cost of the system : the user wants a product without costing him a fortune. Availability calculation is based primarily on knowledge of failure rates and repairs of system components. Availability analysis helps to calculate the ability of a system to provide a required level of performance depending on the level of degradation. Several methods have been used to calculate the availability of a system, amongst which we find the Universal Generating Function (UGF), Inclusion-Exclusion technique, Markov models, etc. These methods employ different probabilistic techniques to evaluate this criterion, but these proposed approaches remain effective only for very specific cases, for example the cases of binary systems. A binary system is a system where only two cases are possible : perfect functioning and total failure. While the transition to multi-state systems (MSS) drastically restricts the application of most of these methods. In real life, the systems corresponds to MSS. In such scenarios, systems and their components can operate at different performance levels between working and failure states. However, the evaluation of the availability of the MSSs is more difficult than in the binary case, because we have to take into account the different combinations of the component failure modes. Throughout this thesis, we search for a method that helps us to compute and to optimize the availability of MSS

碩士
東海大學
資訊工程與科學系
94
In this knowledge-based economy era, the advancement of information and computer science generate enterprise benefit. The effort of managing enterprise software product and data depends on the quality of software. However, software failure may cause more serious damage. For this reason, they spend more costs in software maintenance. The software quality management can reduce software cost, software risk, and sustain enterprise stability effectively and efficiently. Therefore, software maintainability is one of important evaluating subject in the enterprise management arena. There are three types of maintainability proposed in the literature. They are error, functional and environmental maintenance. Different information needs required different type of maintainability in consideration. Therefore, how to measure software maintainability emerged as a popular research topic. In this research, we start at determining the important factors for measuring the software maintainability, followed by collecting the quantitative measure of each characteristics, and developing a complete and effective evaluation model for software maintainability. Based on a particular maintenance type, combined with software product quality measurement model defined in ISO 9126, we propose a measurement construct for evaluating the software maintainability. We described this complex problem by a hierarchical structure, and applied the principal component analysis to process some subjectical data either by simulation or by soliciting from users. By the relationship in this hierarchy, we defined metrics of all attributes. calculated the weighting value or degree of contribution of each attribute, and the dependency between attributes in order to establish a standard for evaluation and process improvement. Finally, we valided our proposed model for stability and applicability using a cross validation technique.

Thesis (M.S.)--University of Wisconsin--Madison, 1999.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 145-148).

Thesis (M.S.)--University of Wisconsin--Madison, 1994.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 60-64).

Tse Yee Kit.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.
Includes bibliographical references (leaves 55-58).
Abstracts in English and Chinese.
Chapter Chapter 1 --- Introduction
Chapter 1.1 --- Geometric Process and Maintenance Problem --- p.1
Chapter 1.2 --- Warranty Problem --- p.5
Chapter 1.3 --- An Outline of the Thesis --- p.8
Chapter Chapter 2 --- Multistate Deteriorative System
Chapter 2.1 --- The Multistate Model --- p.10
Chapter 2.2 --- Long-run Average Cost Per Unit Time --- p.15
Chapter 2.3 --- The Optimal Policy N* --- p.18
Chapter 2.4 --- The Monotonicity of the Optimal Policy --- p.21
Chapter Chapter 3 --- Extended Warranty Model
Chapter 3.1 --- The Extended Warranty Model --- p.30
Chapter 3.2 --- "The Expected Discounted Cost Over the Lifetime Cycle [0,T]" --- p.34
Chapter 3.2.1 --- Consumer's Discounted Cost --- p.34
Chapter 3.2.2 --- Manufacturer's Discounted Cost --- p.37
Chapter 3.3 --- The Exponential Distribution Case --- p.40
Chapter 3.4 --- Numerical Examples --- p.51
Bibliography --- p.55

by Kit-ching To.
Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.
Includes bibliographical references (leaves 64-67).
Abstract also in Chinese.
Chapter Chapter 1 --- Overview --- p.1
Chapter Chapter 2 --- Geometric Process Model --- p.6
Chapter 2.1 --- Introduction --- p.6
Chapter 2.2 --- Some Properties of Geometric Process --- p.7
Chapter 2.3 --- Geometric Process Model for the Exponential Distribution --- p.13
Chapter Chapter 3 --- Analysis of Warranty Policy by a Geometric Process Model --- p.16
Chapter 3.1 --- Introduction --- p.16
Chapter 3.2 --- Consumer's Policy --- p.17
Chapter 3.2.1 --- N-Repair Warranty Policy --- p.19
Chapter 3.2.2 --- n-Renewal Warranty Policy --- p.23
Chapter 3.2.2.1 --- Modified n-Renewal Warranty Policy --- p.25
Chapter 3.2.3 --- Optimal Policy to Consumer --- p.29
Chapter 3.3 --- Manufacturer's Policy --- p.33
Chapter 3.3.1 --- Optimal Policy to Manufacturer --- p.36
Chapter 3.4 --- Numerical Examples --- p.38
Chapter Chapter 4 --- Analysis of a Repairable M/M/l Queueing System by a Geometric Process Model --- p.45
Chapter 4.1 --- Introduction --- p.45
Chapter 4.2 --- Model --- p.46
Chapter 4.2.1 --- Some Reliability Indices --- p.53
Chapter 4.2.1.1 --- Availability --- p.53
Chapter 4.2.1.2 --- Rate of Occurrence of Failures (ROCOF) --- p.54
Chapter 4.3 --- Numerical Method --- p.56
Chapter 4.3.1 --- Results --- p.58
Bibliography --- p.64

Exploration and Production (E&P) project costs within the oil industry are continuously increasing reflecting a reality of more harsh environments, remote locations with minimal existing infrastructure and cost increases for materials and skilled resources. The significant capital expenditures translate to a number of projects either for new or revamped production facilities. Successful project completion requires a series of correct decisions throughout the project life-cycle namely design, construction, operations, maintenance and decommissioning. Using a Reliability, Availability and Maintainability (RAM) model as part of the project decision process is an E&P industry best practice that recently gained acceptance in Hess Corporation. This paper presents the RAM methodology and the gains from its application in a capital project.
text

An analytical method for predicting life-cycle maintainability labor costs is developed. The purpose of the analytical method is to allow the evaluation of products, based on life-cycle labor cost, early in the design process. The Boeing 737-300/400/500 Bleed Air Control System is used as a test model, and the results of the analysis are compared with historical data from this system. Four prospective design changes to the Bleed Air Control System are analyzed to demonstrate the ability of the analytical method to compare different designs or design changes.
Graduation date: 1997