In construction, the most relevant systems used for project management (PM) and project production management (PPM) in the planning and control phases are: Critical Path Method (CPM), Last Planner System ® (LPS ®), and Location-Based techniques (LB). Studies have addressed these systems, mostly in isolated fashions. This study aims to compare and contrast their use in terms of PM and PPM and clarify industry benefits in order to eliminate potential misunderstandings about their use. A survey was administered to construction professionals in Brazil, China, Finland, and the United States. No single system addresses all needs of PM and PPM. CPM is the dominant system when considering these characteristics: primary industry types, type of organization, size of organization, professional position within the organization, and area of work. Contributions to knowledge include that CPM is a contract requirement with perceived benefits associated with critical path analysis; LB and LPS have perceived benefits regarding continuous flow and use of resources, treatment of interferences, and improving production control. All systems were found to have a similar level of benefits for management of contracts, delay and change, and evaluation of the root causes of delays. The industry can benefit from aligning project scheduling methods with project needs.
With group judgments in the context of the Analytic Hierarchy Process (AHP) one would hope for broad consensus among the decision makers. However, in practice this will not always be the case, and significant dispersion may exist among the judgments. Too much dispersion violates the principle of Pareto Optimality at the comparison level and/or matrix level, and if this happens, then the group may be homogenous in some comparisons and heterogeneous in others. The question then arises as to what would be an appropriate aggregation scheme when a consensus cannot be reached and the decision makers are either unwilling or unable to revise their judgments. In particular, the traditional aggregation via the geometric mean has been shown to be inappropriate in such situations. In this paper, we propose a new method for aggregating judgments when the raw geometric mean cannot be used. Our work is motivated by a supply chain problem of managing spare parts in B Natalie M. Scala 123 N. M. Scala et al.the nuclear power generation sector and can be applied whenever the AHP is used with judgments from multiple decision makers. The method makes use of principal components analysis (PCA) to combine the judgments into one aggregated value for each pairwise comparison. We show that this approach is equivalent to using a weighted geometric mean with the weights obtained from the PCA.
Since the reports of Russian interference in the 2016 United States General Election, the security of voting processes has received increased attention from both state and federal authorities. The declaration by the US Department of Homeland Security in January 2017 that election systems be classified as the 17th component of critical infrastructure is just the beginning of a need for more secure voting processes. More recently, the COVID‐19 pandemic and the 2020 US General Election have placed greater emphasis specifically on mail‐based voting processes for electoral systems. The objective of this research is to provide greater insight into potential threats to mail‐based voting processes. Upon identifying an attack tree as an initial structure for evaluation, new threats are postulated, and an updated tree is proposed that accounts for more recent activities. Then, using an established assessment framework, the relative likelihood of each mail‐based voting process attack scenario is identified. The results facilitate providing election officials and policymakers with greater knowledge of how mail‐based voting system vulnerabilities develop as well as specific security measures that may be most beneficial.
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