Mode of access: Internet via World Wide Web. Available at http://hdl.handle.net/1947/10020. / "October 2009" Includes bibliographic references.

M.Ing. / In this thesis aspects of reliability management in a multi-level support environment are researched. Complex systems are generally supported over a number of support levels due to the specialist nature and support infrastructure requirements of the individual subsystems. Such a support approach also ensures optimum availability of the system whilst the subsystems are still in the repair cycle. Once a new system is put into service, it is exposed to the actual operational environment and not the simulated environment that was used to qualify the system during its development. In the operational environment, the system is also exposed to the support infrastructure. These factors, as well as any latent design and production defects, impair the achieved operational reliability of such a system. False removals and premature failures after a repair action further degrade the actual operational reliability of the system. It is generally not possible to qualify the logistic support infrastructure fully before placing a new system into operational service. Support stabilisation should take place early on in the support phase of such a system to correct all latent defects and deficiencies of any of the logistic elements required to support the system. Any latent design and production process defects not eradicated from the system will also surface during the support stabilisation period. Support stabilisation will ensure a constant failure rate for the operational life of the system at the lowest life-cycle cost. The methodology used to achieve system reliability growth during the support phase is similar to reliability growth during the development phase. However, additional variables of the operational and support environment are now included in the reliability growth process. The process is also further compounded by the geographic separation of the different levels of support each generally with their own support management infrastructure. The proposed approach is: get total management commitment and close the management loop over the different levels of support. establish the root cause of every system failure implement a test, analyse and fix policy eliminate ineffective repair actions ensure that the system operational environment is within the system specification remove latent design defects from the system correct deficiencies in the logistic elements.

Software maintainability is one of the most crucial quality attributes of a software product. Software engineering researchers and practitioners have devoted considerable effort to developing “good design” methods, rules and principles to improve software maintainability. But before we can validate the effectiveness of these methods, we first need an approach to measure software maintainability. The existing maintainability measures usually have limited scope and accuracy since they either isolate the software from its environment and focus only on the technical properties of the software, or measure a confounding effect of various factors involved in the maintenance process. Furthermore, these measures are often defined and collected on a coarse-grained level and provide no insight into what makes software difficult to change. This research addresses the problems associated with software maintainability measurement by adapting the concepts of task complexity from the human behavior domain to the software engineering domain. This dissertation involves developing and validating a measurement model for measuring the maintainability of software, to provide a better understanding of the difficulty in modifying software and the effect of software design methods on software maintainability. A measurement protocol and a tool have been developed to support the application of the measurement method.

The aim of this research is to propose an alternative approach to determine the maintainability prediction for aircraft components. In this research, the author looks at certain areas of the maintainability prediction process where missteps or misapplications most commonly occur. The first of these is during the early stage of the Design for Maintainability (DfMt) process. The author discovered the importance of utilising historical information or feedback information. The second area is during the maintainability prediction where the maintenance of components is quantified; here, the author proposes having the maximum target for each individual maintainability component. This research attempts to utilise aircraft maintenance historical data and information (i.e. feedback information systems). Aircraft feedback information contains various types of information that could be used for future improvement rather than just the failure elements. Literature shows that feedback information such as Service Difficulty Reporting System (SDRS) and Air Accidents Investigation Branch, (AAIB) reports have helped to identify the critical and sensitive components that need more attention for further improvement. This research consists of two elements. The first is to identity and analyse historical data. The second is to identify existing maintainability prediction methodologies and propose an improved methodology. The 10 years’ data from Federal Aviation Administration (FAA) SDRS data of all aircraft were collected and analysed in accordance with the proposed methodology before the processes of maintainability allocation and prediction were carried out. The maintainability was predicted to identify the potential task time for each individual aircraft component. The predicted tasks time in this research has to be in accordance with industrial real tasks time were possible. One of the identified solutions is by using maintainability allocation methodology. The existing maintainability allocation methodology was improved, tested, and validated by using several case studies. The outcomes were found to be very successful. Overall, this research has proposed a new methodology for maintainability prediction by integrating two important elements: historical data information, and maintainability allocation. The study shows that the aircraft maintenance related feedback information systems analyses were very useful for deciding maintainabilityeffectiveness; these include planning, organising maintenance and design improvement. There is no doubt that historical data information has the ability to contribute an important role in design activities. The results also show that maintainability is an importance measure that can be used as a guideline for managing efforts made for the improvement of aircraft components.

The aim of this research is to propose an alternative approach to determine the maintainability prediction for aircraft components. In this research, the author looks at certain areas of the maintainability prediction process where missteps or misapplications most commonly occur. The first of these is during the early stage of the Design for Maintainability (DfMt) process. The author discovered the importance of utilising historical information or feedback information. The second area is during the maintainability prediction where the maintenance of components is quantified; here, the author proposes having the maximum target for each individual maintainability component. This research attempts to utilise aircraft maintenance historical data and information (i.e. feedback information systems). Aircraft feedback information contains various types of information that could be used for future improvement rather than just the failure elements. Literature shows that feedback information such as Service Difficulty Reporting System (SDRS) and Air Accidents Investigation Branch, (AAIB) reports have helped to identify the critical and sensitive components that need more attention for further improvement. This research consists of two elements. The first is to identity and analyse historical data. The second is to identify existing maintainability prediction methodologies and propose an improved methodology. The 10 years’ data from Federal Aviation Administration (FAA) SDRS data of all aircraft were collected and analysed in accordance with the proposed methodology before the processes of maintainability allocation and prediction were carried out. The maintainability was predicted to identify the potential task time for each individual aircraft component. The predicted tasks time in this research has to be in accordance with industrial real tasks time were possible. One of the identified solutions is by using maintainability allocation methodology. The existing maintainability allocation methodology was improved, tested, and validated by using several case studies. The outcomes were found to be very successful. Overall, this research has proposed a new methodology for maintainability prediction by integrating two important elements: historical data information, and maintainability allocation. The study shows that the aircraft maintenance related feedback information systems analyses were very useful for deciding maintainabilityeffectiveness; these include planning, organising maintenance and design improvement. There is no doubt that historical data information has the ability to contribute an important role in design activities. The results also show that maintainability is an importance measure that can be used as a guideline for managing efforts made for the improvement of aircraft components.

The importance of building maintainable software is being recognized in the community of software development. By developing software that is easy to maintain, the time and resources needed to perform the modifications may be decreased. This will in turn mean economical savings and increased profits. Architectural software patterns are said to promote the development of maintainable software. The aim of this project was therefore to investigate whether architectural software patterns possess this property or not. A case study was performed where two candidate architectures were compared using a method called Architectural analysis of modifiability. This method uses change scenarios and modification ratios to identify differences between candidate architectures. A system developed at Ericsson Microwave Systems AB was used for the case study. One of the candidate architectures consisted of two architectural software patterns: the Layers pattern and the Model-View-Controller pattern. The architecture analysis showed that the Layers pattern did promote maintainability whereas the Model-View-Controller pattern did not, from the basis of judgement associated with the method.

<p>The importance of building maintainable software is being recognized in the community of software development. By developing software that is easy to maintain, the time and resources needed to perform the modifications may be decreased. This will in turn mean economical savings and increased profits.</p><p>Architectural software patterns are said to promote the development of maintainable software. The aim of this project was therefore to investigate whether architectural software patterns possess this property or not. A case study was performed where two candidate architectures were compared using a method called Architectural analysis of modifiability. This method uses change scenarios and modification ratios to identify differences between candidate architectures. A system developed at Ericsson Microwave Systems AB was used for the case study.</p><p>One of the candidate architectures consisted of two architectural software patterns: the Layers pattern and the Model-View-Controller pattern. The architecture analysis showed that the Layers pattern did promote maintainability whereas the Model-View-Controller pattern did not, from the basis of judgement associated with the method.</p>

Thesis (M.S.)--Building Construction, Georgia Institute of Technology, 2005. / Dr. Felix T. Uhlik III, Committee Member ; Mr. Cliff Stern, Committee Member ; Dr. Rita Oberle, Committee Member ; Ms. Kathy O. Roper, Committee Chair. Includes bibliographical references.

Digitized by Kansas Correctional Industries

Thesis (M. Sc.)--University of Alberta, 2009. / Title from PDF file main screen (viewed on Nov. 27, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Engineering Management, Department of Mechanical Engineering, University of Alberta." Includes bibliographical references.