AAU Institutional Repository (AAU-ETD)
Addis Ababa University Institutional repository is an open access repository that collects,preserves, and disseminates scholarly outputs of the university. AAU-ETD archives' collection of master's theses, doctoral dissertations and preprints showcase the wide range of academic research undertaken by AAU students over the course of the University's long history.
How to Submit Your Work
The repository contains scholarly work, both unpublished and published, by current or former AAU faculty, staff, and students, including Works by AAU students as part of their masters, doctoral, or post-doctoral research
- All AAU faculty, staff, and students are invited to submit their work to the repository. Please contact the library at your college.
You may contact digirep@aau.edu.et.with any questions about the repository
Colleges,Institutes in AAU-ETD
Select a college,institute to browse its collections.
Recent Submissions
The Determinants and Business Impact of Additive Manufacturing Technology Adoption: A Case of Ethiopian Metal Manufacturing Industries
(Addis Ababa University, 2024-06) Amanuel Haile; Eshetie Berhan (PhD); Behailu Kemaw (Mr.) Co-Adviso
Additive Manufacturing (AM) technology, also called 3D-printing, is a disruptive technology providing opportunities and huge potential benefits through innovative way of manufacturing products. This study is concerned with identifying the determinants for adoption of Additive Manufacturing technology within Ethiopian metal manufacturing industries. In light of this objective, the study adopts both quantitative and qualitative approaches with purposive sampling. The quantitative approach used 7-likert scale questionnaire for empirical analysis of the data to determine the factors that influence the adoption of AM technology. For the qualitative approach, an interview is conducted to determine the business impact and the challenges of adopting AM technology. A sample of team leaders, engineers, metal researchers, technicians, IT professionals and quality controllers is taken to capture their opinions, views and reflections about the determinants for adopting AM technology in metal manufacturing industries. A self-administered questionnaire is used to rate the influence of technological, organizational, and environmental determinants on the decision to adopt the technology. Both SPSS and SmartPLS software tools are used for descriptive statistics analysis and structural equation modeling (SEM) of the collected data respectively. Results indicate that out of the determinants, the perceived value, perceived cost, top management support, organizational readiness, external pressure and perceived outside support affecting significantly a decision for adopting AM technology. The study further explores the benefits, potential business impact and the challenges of adopting AM technology in metal manufacturing industries. This study's contribution is to provide academics, business people and policymakers with insightful information about the determinants that influence AM technology adoption and its benefits enabling them to implement the necessary initiatives or policies that are essential for the technology to be adopted successfully. Lastly the study recommends further research in this field.
Experimental Investigation on the Mechanical Properties of Heat-Treated AISI O2 Tool Steel for the Application of Mild Steel Metal Cutting Die Block Design
(Addis Ababa University, 2023-06) Sisay Kebede; Haileleoul Sahle (PhD)
The heat treatment process can change the mechanical properties like impact toughness, wear resistance, and hardness in order to avoid tool surface chemistries change heat treatment distortion must be controlled, and a careful balance must be maintained. Producing successful tools and dies control of the heat treatment process is one of the most critical steps. Industries are highly demanding reliable tool steel metal to effectively develop or process components by machine related processes, hence producing dependable parent die material is crucial for tool die design. In this study, the material behavior of AISI O2 investigated in order to find the optimum heat treatment processing parameter for the application of die block design.
This research find the optimum hardness, impact energy and wear resistance of the selected material using heat treatment process parameter, Austenitizing temperature, tempering temperature and soaking time for tempering. 36Specimens prepared for the corresponding target test. Taguchi L9 orthogonal array design of experiment was used to conduct the experiment, and for each set test category, two specimen were taken to reduce variability occurred due to noise factors. MINITAB 2022 software used to identify the optimum set up of input factors with their corresponding levels. Main effect plot for signal to noise ratio revealed that tempering temperature and Austenizing temperature have a great influence on the responses.
According to Taguchi Grey relational analysis Austenizing temperature 8050C, tempering temperature 2000C, soaking time for tempering 2 hours are the optimum set up of heat treatment process parameter. Generated mechanical properties results are:- Hardness 63HRC, Toughness 8.25J and wear resistance (volume loos /Mass loos/) (2.47128mm3/0.0189gram/) per 5 minutes, in order to be economical and a negligible difference of results there is also alternative result other than Taguchi Optimum result, which is at Austenizing temperature 790oC, tempering temperature 200oC and holding time of 1.5hr, 62.875HRC,8.25J and 2.47193mm3 mass loss is acceptable.
For the case of wear resistance test, the loss calculated within 5minutes.
Results from this work will be applicable for die designer and die manufacture.
Developing Integrated Quality and Safety Management System Model in the Process Industry: A Case of Awash Wine
(Addis Ababa University, 2024-06) Henok Eshetu; Kassu Jilcha (PhD); Birhanu Tolasa (Mr.) Co-Advisor
Quality and safety management systems are essential in the beverage industry for ensuring the production of safe, high-quality beverages and increasing productivity and efficiency. Currently, Awash Wine faces significant challenges, such as employee safety problems, inefficiency, and the unproductive use of full employee working hours per day for wine-making processes. The primary objective of this research is to identify any existing gaps in the quality and safety management system of the case company. After assessing these gaps and their implications, the study aims to find effective solutions to address the identified issues, ultimately leading to improved productivity. The research methodology involves conducting a comprehensive literature review, collecting, and analyzing quantitative and qualitative data on the main factors that affect the productivity of the company regarding safety and quality. The collected data using both primary and secondary data collection methods was thoroughly analyzed using statistical software SPSS. The research methodology involves conducting a comprehensive literature review, collecting and analyzing quantitative and qualitative data on the main factors that affect the productivity of the company concerning safety and quality. The data was collected using both primary and secondary methods and thoroughly analyzed using the statistical software SPSS. The quantitative data was obtained from questionnaires administered to 86 employees, and their responses were analyzed using SPSS. The analysis revealed that continuous improvement, employee involvement, and safety evaluation and monitoring have a substantial positive correlation with organizational productivity, with results of r = 0.546, p = 0.000; r = 0.602, p = 0.000; and r = 0.572, p = 0.000, respectively. Additionally, the analysis showed that safety and quality leadership and customer focus also have a positive relationship with organizational productivity, albeit with a relatively lower result, with r = 0.489, p = 0.000 and r = 0.456, p = 0.000, respectively. The study's findings propose that a company's productivity is most impacted by two critical factors - the lack of monitoring and assessment of safety during regular operations, and the failure to prioritize continuous improvement. The researcher encountered constraints in terms of time, money, and access to important people and resources at Awash Wine, which could limit the scope and depth of the study. This indicates that the organization does not place a strong emphasis on enhancing its working culture in terms of continuous improvement. The study has the potential to be a useful tool for academics and industry consultants who are seeking to improve customer satisfaction and productivity in the process industry.
Improving Service Delivery through Facility Layout Optimization: A Process Mapping Analysis in Teklehaimanot Health Center
(Addis Ababa University, 2024-07) Heran Bereket; Ameha Mulugeta (PhD); Birhanu Tolosa (Mr.) Co Advisor
Teklehaimanot Health Center plays a crucial role in providing healthcare service to the community in Addis Ababa, Ethiopia. However, providing service with short waiting and service time to the community has been presented as a challenge in the healthcare facility. Teklehaimanot Health Center still struggles to deliver quality service to patients due to suboptimal layout design of the health center facility. This paper aims to optimize the facility layout of the outpatient department to improve the service delivery of Teklehaimanot Health Center. The objective is to develop a health center facility layout in Teklehaimanot Health Center that will improve service delivery by exchanging the department room by considering patient path. The research methodology consists of qualitative and quantitative data collection related to the time for every operation that takes place under the outpatient department. The proposed research integrates process mapping analysis, time study, facility layout techniques, multi-criteria decision making, and simulation to address the issue presented. Service time and waiting time are the key measuring variables. From the existing facility, a redesigned layout is developed, and simulation is used to validate the new optimized layout. By utilizing process mapping analysis integrated with time study and facility layout improvement, the research provides data-driven recommendations for the health center facility layout with minimum unnecessary movement of patients and minimum travel distance. The impact is evaluated by measuring the variables of service and waiting time the improvements in waiting time and service time achieved through the facility layout changes are likely very significant and impactful for the Teklehaimanot Health Center. Based on the result, the optimized proposed facility layout minimizes the average waiting time from 2.5 hours to 2.01 hours, which is a 19.60% reduction, and minimizes the service time from 0.79 hours to 0.64 hours, which is an 18.98% reduction. This shows a positive impact on improving service delivery and patient satisfaction in the health center.
Developing AI-based Preventive Maintenance Model for BGI Ethiopia: Washing Head
(Addis Ababa University, 2024-07) Tsigereda Abebe; Gezahegn Tesfaye (PhD)
.for implementing real-time monitoring and continuous modelupdates to sustain and enhance the benefits improve production processes and reduce operational costs.The study concludes with recommendations value of AI-driven preventive maintenance in the breweryindustry, suggesting broader applications to kegs but also enhances the reliability and efficiency of theproduction line. The findings demonstrate the This predictive approach not only minimizesdowntime by preventing the processing of faulty performance, accurately forecasting potential kegrejections and enabling preemptive maintenance actions. including AdaBoost, to predict the readinessstate of Head-4. The AdaBoost model exhibited superior generating synthetic data to augment thedataset, the study trained several machine learning models, integrating real-time data from theComputerized Maintenance Management System (CMMS) and maintenance model to improveoperational efficiency and reduce these false rejections. By substantial downtime andeconomic losses. The objective of this research is to develop a predictive particularly at the washingHead-4. These rejections, caused by steam supply inconsistencies, result in linedue to the frequent rejection of kegs by the Slimline Monobloc 50 filler machine,