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- All Subjects: Medical Ethics
- Creators: Askin, Ronald G
Description
Assembly lines are low-cost production systems that manufacture similar finished units in large quantities. Manufacturers utilize mixed-model assembly lines to produce customized items that are not identical but share some general features in response to consumer needs. To maintain efficiency, the aim is to find the best feasible option to balance the lines efficiently; allocating each task to a workstation to satisfy all restrictions and fulfill all operational requirements in such a way that the line has the highest performance and maximum throughput. The work to be done at each workstation and line depends on the precise product configuration and is not constant across all models. This research seeks to enhance the subject of assembly line balancing by establishing a model for creating the most efficient assembly system. Several realistic characteristics are included into efficient optimization techniques and mathematical models to provide a more comprehensive model for building assembly systems. This involves analyzing the learning growth by task, employing parallel line designs, and configuring mixed models structure under particular constraints and criteria. This dissertation covers a gap in the literature by utilizing some exact and approximation modeling approaches. These methods are based on mathematical programming techniques, including integer and mixed integer models and heuristics. In this dissertation, heuristic approximations are employed to address problem-solving challenges caused by the problem's combinatorial complexity. This study proposes a model that considers learning curve effects and dynamic demand. This is exemplified in instances of a new assembly line, new employees, introducing new products or simply implementing engineering change orders. To achieve a cost-based optimal solution, an integer mathematical formulation is proposed to minimize the production line's total cost under the impact of learning and demand fulfillment. The research further creates approaches to obtain a comprehensive model in the case of single and mixed models for parallel lines systems. Optimization models and heuristics are developed under various aspects, such as cycle times by line and tooling considerations. Numerous extensions are explored effectively to analyze the cost impact under certain constraints and implications. The implementation results demonstrate that the proposed models and heuristics provide valuable insights.
ContributorsAlhomaidi, Esam (Author) / Askin, Ronald G (Thesis advisor) / Yan, Hao (Committee member) / Iquebal, Ashif (Committee member) / Sefair, Jorge (Committee member) / Arizona State University (Publisher)
Created2023
Description
In 2014, the Centers for Medicare and Medicaid Services (CMS), which oversees the federal Clinical Laboratories Improvement Amendments (CLIA) program, issued guidance that the CLIA requirements apply when researchers seek to return individual-level research findings to study participants or their physician (Centers for Medicare & Medicaid Services, 2014). The present study explores the stance of U.S. Institutional Review Boards (IRBs) toward the applicability of and compliance with the CLIA regulations when studies plan to return individual research results (RIRR). I performed a document content analysis of 73 IRB policies and supporting documents from 30 United States (U.S.) institutions funded for biomedical research by the National Institutes of Health in 2017. Documents analyzed included policies, procedures, guidance, protocol and consent templates, and miscellaneous documents (such as IRB presentations) found to address the RIRR to study participants. I used qualitative content and document analysis to identify themes across institutions related to the CLIA regulations and the RIRR. Basic descriptive statistics were used to represent the data quantitatively. The study found that 96.67% (n=29) of institutions had documents that addressed the RIRR to participants. The majority of the institutions had at least one document that referenced the CLIA regulations when discussing the practice of disclosing participant-specific results [76.67% (n=23)]. The majority of institutions [56.67% (n=17)] indicated that they require compliance with the CLIA regulations for returning individual study findings to participants, while 13.33% (n=4) recommended compliance. The intent of two (6.67%) institutions was vague or unclear, while seven (26.67%) institutions were silent on the topic altogether. Of the 23 institutions that referenced “CLIA” in their documents, 52.17% only mentioned CLIA in a one or two-sentence blurb, providing very little guidance to investigators. The study results provide evidence that the majority of U.S. biomedical institutions require or recommend compliance with CLIA stipulations when investigators intend to return individual research results to study participants. However, the data indicates there is heterogeneity and variation in the quality of the guidance provided.
ContributorsBuchholtz, Stephanie (Author) / Robert, Jason S. (Thesis advisor) / Ellison, Karin D. (Committee member) / Carpten, John D. (Committee member) / Craig, David W. (Committee member) / Marchant, Gary E. (Committee member) / Arizona State University (Publisher)
Created2021