Operations research and computers

operational research

Understanding construction delay analysis and the role of pre-construction programming

Copyright © 2013, American Society of Civil Engineers. This is the author's accepted manuscript. The final published article is available from the link below.Modern construction projects commonly suffer from delay in their completions. The resolution of time and cost claims consequently flowing from such delays continues to remain a difficult undertaking for all project parties. A common approach often relied on by contractors and their employers (or their representatives) to resolve this matter involves applying various delay analysis techniques, which are all based on construction programs originally developed for managing the project. However, evidence from literature suggests that the reliability of these techniques in ensuring successful claims resolution are often undermined by the nature and quality of the underlying program used. As part of a wider research carried out on delay and disruption analysis in practice, this paper reports on an aspect of the study aimed at exploring preconstruction stage programming issues that affect delay claims resolutions. This aspect is based on an in-depth interview with experienced construction planning engineers in the United Kingdom, conducted after an initial large-scale survey on delay and disruption techniques usage. Summary of key findings and conclusions include: (1) most contractors prefer to use linked bar chart format for their baseline programs over conventional critical path method (CPM) networks; (2) baseline programs are developed using planning software packages. Some of these pose difficulties when employed for most delay analysis techniques, except for simpler ones; (3) manpower loading graphs are not commonly developed as part of the main deliverables during preconstruction stage planning. As a result, most programs are not subjected to resource loading and leveling for them to accurately reflect planned resource usage on site. This practice has detrimental effects on the reliability of baseline programs in their use for resolving delay claims; and (4) baseline program development involves many different experts within construction organizations as expected, but with very little involvement of the employer or its representative. Active client involvement is however quite important as it would facilitate quick program approval/acceptance before construction, a necessary requirement for early delay claims settlement, which otherwise are often left unresolved long after the delaying events with the potential of generating into expensive disputes. The study results provide a better understanding of the key issues that need attention if improvements are to be made in delay claim resolutions. Additional research focusing on the testing of these results using a much larger sample and rigorous statistical analysis for generalization purposes would be helpful in advancing the limited knowledge of this subject matter

Systems Engineering: Availability and Reliability

Current trends in Industry 4.0 are largely related to issues of reliability and availability. As a result of these trends and the complexity of engineering systems, research and development in this area needs to focus on new solutions in the integration of intelligent machines or systems, with an emphasis on changes in production processes aimed at increasing production efficiency or equipment reliability. The emergence of innovative technologies and new business models based on innovation, cooperation networks, and the enhancement of endogenous resources is assumed to be a strong contribution to the development of competitive economies all around the world. Innovation and engineering, focused on sustainability, reliability, and availability of resources, have a key role in this context. The scope of this Special Issue is closely associated to that of the ICIE’2020 conference. This conference and journal’s Special Issue is to present current innovations and engineering achievements of top world scientists and industrial practitioners in the thematic areas related to reliability and risk assessment, innovations in maintenance strategies, production process scheduling, management and maintenance or systems analysis, simulation, design and modelling

Engineering Aggregation Operators for Relational In-Memory Database Systems

In this thesis we study the design and implementation of Aggregation operators in the context of relational in-memory database systems. In particular, we identify and address the following challenges: cache-efficiency, CPU-friendliness, parallelism within and across processors, robust handling of skewed data, adaptive processing, processing with constrained memory, and integration with modern database architectures. Our resulting algorithm outperforms the state-of-the-art by up to 3.7x

Research reports: 1991 NASA/ASEE Summer Faculty Fellowship Program

The basic objectives of the programs, which are in the 28th year of operation nationally, are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA Centers. The faculty fellows spent 10 weeks at MSFC engaged in a research project compatible with their interests and background and worked in collaboration with a NASA/MSFC colleague. This is a compilation of their research reports for summer 1991

Processing techniques development

There are no author-identified significant results in this report