A reliability centered maintenance decision system for a discrete part manufacturing facility

This thesis develops and validates the framework of a specialized maintenance decision support system for a discrete part manufacturing facility. Its construction utilizes a modular approach based on the fundamental philosophy of Reliability Centered Maintenance (RCM). The proposed architecture uniquely integrates System Decomposition, System Evaluation, Failure Analysis, Logic Tree Analysis, and Maintenance Planning modules. It presents an ideal solution to the unique maintenance inadequacies of modern discrete part manufacturing systems. Well established techniques are incorporated as building blocks of the system's modules. These include Failure Mode Effect and Criticality Analysis (FMECA), Logic Tree Analysis (LTA), Theory of Constraints (TOC), and an Expert System (ES). A Maintenance Information System (MIS) performs the system's support functions. Validation was performed by field testing of the system at a Miami based manufacturing facility. Such a maintenance support system potentially reduces downtime losses and contributes to higher product quality output. Ultimately improved profitability is the final outcome. ^

Optimization of pavement maintenance and rehabilitation programming using shuffled complex evolution algorithm

The major barrier to practical optimization of pavement preservation programming has always been that for formulations where the identity of individual projects is preserved, the solution space grows exponentially with the problem size to an extent where it can become unmanageable by the traditional analytical optimization techniques within reasonable limit. This has been attributed to the problem of combinatorial explosion that is, exponential growth of the number of combinations. The relatively large number of constraints often presents in a real-life pavement preservation programming problems and the trade-off considerations required between preventive maintenance, rehabilitation and reconstruction, present yet another factor that contributes to the solution complexity. In this research study, a new integrated multi-year optimization procedure was developed to solve network level pavement preservation programming problems, through cost-effectiveness based evolutionary programming analysis, using the Shuffled Complex Evolution (SCE) algorithm.^ A case study problem was analyzed to illustrate the robustness and consistency of the SCE technique in solving network level pavement preservation problems. The output from this program is a list of maintenance and rehabilitation treatment (M&R) strategies for each identified segment of the network in each programming year, and the impact on the overall performance of the network, in terms of the performance levels of the recommended optimal M&R strategy. ^ The results show that the SCE is very efficient and consistent in the simultaneous consideration of the trade-off between various pavement preservation strategies, while preserving the identity of the individual network segments. The flexibility of the technique is also demonstrated, in the sense that, by suitably coding the problem parameters, it can be used to solve several forms of pavement management programming problems. It is recommended that for large networks, some sort of decomposition technique should be applied to aggregate sections, which exhibit similar performance characteristics into links, such that whatever M&R alternative is recommended for a link can be applied to all the sections connected to it. In this way the problem size, and hence the solution time, can be greatly reduced to a more manageable solution space. ^ The study concludes that the robust search characteristics of SCE are well suited for solving the combinatorial problems in long-term network level pavement M&R programming and provides a rich area for future research. ^

Boundary maintenance in Qatar: Interpretation of domination, segregation and subordination

This study explores the interaction of expatriates in Qatar and their perception of their subordination. The study design included participant observation in an all female University and University housing as well as interviews with Qatari government agencies and ministries, expatriate embassies and expatriates. Semi-structured interviews were conducted across seven expatriate groups: domestic workers, unskilled laborers, semiskilled, professionals, housewives, second-generation expatriates with host country other than Qatar, second-generation expatriates with host country Qatar, and Gulf Cooperation Council citizens. Forty-two subjects completed the interview schedule while 87 interviews were incomplete. ^ Physical control of expatriates occurs through the Gulf practice of sponsorship (The Kafeel System), and local cultural and Islamic related controls intertwined with the Arab Code of honor. Interviews and observations revealed rankings of Arabs and foreigners which emphasize Qatari superiority such as tribal identity, moral ranking of female groups by dress, legal protection and power, sexual consideration and desexualization and salaries and job opportunities based on nationality and ethnicity. Individuals who desire to transcend boundaries into the Qatari realm through citizenship or marriage view Qataris as possessing the “image of the unlimited good” and have acquired Qatari social and cultural capital. Members from all expatriate groups engaged in various forms of resistance to labor and gender domination which ranged from forms of “exit,” expressing a hidden transcript in the privacy of their own group, disguised resistance in public, and occasionally, direct confrontation with the Qatari. Although the legal arena created the appearance that worker's needs were being addressed, laborers engaged in forms of “exit” to escape their oppression. Omani students in the hostel disguised their resistance by spreading gossip, nick-naming homosexual Qatari students at the University, acting out a skit depicting their exclusion from Qatari privilege, spreading rumors of impending freedom, and singing songs of despair in the courtyard. Other sites of resistance were expatriate embassies, the road, the newspaper and technology. This study emphasizes that blaming oppression of the expatriate worker on globalization is a simplistic view of oppression in the Gulf, and ignores complex issues within Qatari society and other Gulf States. Sponsorship, servitude, and gender segregation intersect in Qatar to create a system of segregation and domination of expatriates. ^