Construction Technology and Management

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Browsing Construction Technology and Management by Author "Abraham Assefa"

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    Investigation on Construction planning and Scheduling Methods and Tools in Case of Federal Road Construction Projects
    (Addis Ababa University, 2024-08) Beshir Mudesir; Abraham Assefa
    Any effective construction management system should have as its primary objective to completing the project within allotted budget, on schedule and within necessary quality standards. Project planning and scheduling tools and methods are important tools for Contractors in ensuring efficient and effective project planning and scheduling. Traditional planning and scheduling procedures are widely used by road contractors while establishing the work program. However, due to the growing size and complexity of construction projects, as well as rapid technological progress, a move from traditional approaches to more technology intensive ways have required. Due to this, the study looks into the present planning and scheduling methods and tools adopted by the contractors in case of federal road projects, the factors that influence their choices, and the problems encountered using the chosen planning and scheduling tools and methods are studied. Road contractors working with Ethiopian Road Administration were included in the research. The questionnaire survey and case study were used for data collection and respondents are ERA road contractors. According to the findings, the most popular planning and scheduling approach used by local and foreign contractors is the bar chart, which is followed by critical path methods(CPM) in activity on arrow (AOA). Contractors, on the other side, rarely use the LSM, PERT, or GERT methodologies. Specialized software was most commonly used to create bar charts, milestone charts, and CPM in AOA, PDM, PERT, and GERT, while computer spreadsheet systems were usually utilized to create s-curve charts and linear scheduling method (LSM) The most widely used specialty software is Microsoft Project, whereas the most widely used computer spreadsheet system is Microsoft Excel. The most important criteria determining the choice of planning and scheduling methodologies are the size and complexity of projects. The requirements for detail information, computer hardware and software, and the inability to control the project's critical path are all problems experienced when employing non-network based approaches (bar chart, s-curve chart, milestone chart, and LSM). On the other hand, time Consuming, the need for a skilled and experienced Planner, detailed information, computer skills and software, and insufficient training are all major issues with adopting this method.
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    Use of Historical Bid Data to Estimate Future Unit Rate for Selected Building Work Items
    (Addis Ababa University, 2026-05-01) Etsegenet Kenenissa; Abraham Assefa
    This research work used historical bid unit rates of selected items found in most construction projects and have less specification deviation from one another on building projects to create a model that enables estimation of future unit rates. The scope was limited to projects in Ethiopia.Data for a total of 37 projects with 80 building blocks were collected and analyzed. Analysis using multiple linear regression technique was performed between the dependent variables (unit rates) and independent variables which are quantity of the work item; the distance of the project from the capital city of the country; building plot area,; total floor area; number of stories/floors; contract signing date; USD to ETB exchange rate on contract signing date; client type; function of the building and contract type. From the analysis, the regression models predicted the unit rate of C-15 sub structure concrete work with coefficient of determination as high as 0.906. Where, high value of coefficient of determination reveals that the link among outcome and predictor variable is respectable. Whereas, the least accurate model was developed for superstructure C20 concrete unit rate with coefficients of determination of 0.403.The key cost drivers or independent variables that appear in most of the regression models are contract signing date, distance of the project from Addis Ababa, Contract type, number of stories and USD to ETB exchange rate. This thesis has proposed a single formula to estimate unit rate for the selected work items. However, it is highly recommended to include more data for improved accuracy and predictive capability of the models. Therefore, the models developed in this research should serve as a stepping stone for further research on the topic rather than generalizing tool beyond the sample projects.