Sustainable Project Management: Reducing the Risk of Cost Inaccuracy Using a PLS-SEM Approach

Determining the factors leading to cost inaccuracy in infrastructure projects relates to sustainability by improving the cost performance of the projects (economic sustainability) and reducing the waste of available resources (environmental sustainability). This study investigates the effects of various factors affecting the cost performance of large-scale road projects in Norway in both the planning and construction phases. To this aim, a quantitative approach using a questionnaire survey was employed to understand the attitude of practitioners towards various factors causing cost increases. An advanced multivariate statistical approach of Partial Least Square Structural Equation Modeling (PLS-SEM) and Relative Importance Index (RII) was utilized to analyze the questionnaire responses. The results of the RII analysis show that local wishes, defective estimations, and long processing times had the most impact on the cost increase during the planning phase. At the same time, scope changes, market conditions, and unforeseen ground conditions were the most influential parameters in the construction phase. Moreover, the results obtained from PLS-SEM reveal that external related factors had the most influence among the other grouped factors (i.e., pre-construction, project management and contractual relationship, contractor’s site management, and external) on cost overrun during the construction phase. Increasing the knowledge of these factors will allow for developing relevant project management approaches targeted at improving economic and environmental sustainability within both the planning and construction phases.

Biocomposites Using Whole or Valuable Component-Extracted Microalgae Blended with Polymers: A Review

Global demand for plastics has increased steadily alongside industrial development. Despite their versatility and convenience, environmental pollution caused by plastics are a major issue. With a reduction in the market size of plastics being seemingly impossible, bioplastics may become key to tackle this issue. Among a wide range of sources of bioplastics, microalgae have come into the limelight. While abundant and valuable components in microalgae have the potential to replace preexisting plastics, complex processes and low cost performances have prevented them from entering the market. In this study, we examined techniques for biocomposites in which polymers are blended with microalgae. We focused on microalgae-based biocomposite blending processed from the perspective of functionality and cost performance.

Latent Errors and Visible Earned Value: How the Evolutionary Model Integrates Earned Value Metrics with Project System Dynamics

A project model is presented that weaves together ideas from earned value project management and systems dynamics. It is able to adjust to increasingly unhealthy actual project behaviors in ways that preserve the signature pattern of the staffing histograms observed in the real world and provide a tool for managers to correct projects that are not meeting the plan. Starting from the planned staffing histogram and the project performance baseline, the model captures the delay and cost of experience dilution, includes the unplanned-for effort that is revealed in the typical pattern of the Cost Performance Index, assesses progress using the actual cost to date and the earned value to date, and adjusts staffing, scope, or both, to complete the project on schedule. A new method of approximating work remaining, called project-to-date, is shown to track the planned staffing histogram better than the commonly used fraction-complete method.

Rock Fragmentation Evaluation towards Blast-To-Mill Concept of Blast Optimization in Hard Rock Mines

Traditional blast optimisation studies ensure efficient mining operation but ignore potential impact of blasting on primary crushing. The performance of the primary crusher is key to the ore beneficiation process. Optimisation studies conducted through the mining operations to the comminution circuit is vital to the mine-to-mill concepts in the mining industry. In this approach, an innovative approach to the assessment of in-situ blasting is proposed and evaluated. This approach focuses on the acceptability of rock fragments on the Run-of-Mine (ROM) pad as opposed to the pits. Fragmentation analysis was conducted in the pit and on the ROM pad. A correlation efficiency of 0.92 was realized between the measured rock fragments in the pit and that on the ROM pad. About 10% of the rock fragments in the pit were classified as boulders while about 30% of the same rock fragments deposited on the ROM pad were classified as boulders. However, about 30% of the rockpile on the ROM pad was estimated to be lower than the Close Side Setting (CSS) of the primary crusher. It is recommended that future research evaluates the energy consumption and its related cost at the primary crusher in comparison to in-pit fragmentation and mucking cost performance.

CFD Simulation on Improving Water Quality based on Various Aerator Models to Demonstrate Cost Performance Analysis

There are many types of aerator that can be used to perform a water treatment process either from air to water or from water to air approaches. Other than focusing on the performance itself, the usage cost of aerator should be forecasted in detail too to have a sustainable and economical method in remediating the polluted water. Therein, the cost performance analysis was demonstrated by performing a computational fluid dynamics (CFD) simulation on improving water quality based on various aerator models. The simulation was focused in a small-scale aeration tank that consists of a mixing chamber, air duct, and a few of bubble diffusers. The improvement of water quality was assessed by calculating the number of gas bubble particles produced by 4 different configurations of aerator model, namely aerator model A, B, C and D, respectively. Results found that the aerator model D (5 bubble diffuser at 620 L/min) produces the highest number of gas particles up to 72.2%. However, the aerator model C (5 bubble diffuser at 300 L/min) was found to achieve the most efficient and sustainable approach based on energy consuming and cost of aerator configuration when compared to the other aerator models.

Comparison and Evaluation of China’s Urban Social Security Financing System Before and After the Reform

The sustainability of China’s urban social security financing system has recently been seriously questioned. This article divides the financing system’s development into two periods (before and after reform). It compares the capital collection and the distribution and circulation structures and reviews the financing system before and after reform. In this study, we also discuss and explain the ‘empty account’ phenomenon, which severely undermines the financing system’s sustainability. We allege that the money accumulation system adopted after reform, which correlates personal accounts with the social pool, is not running as designed but as a ‘pay-as-you-go’ system. After evaluating the efficiency and cost performance of both periods, testing the financing system’s sustainability and correlating the system during both time periods with economic and social development, we find that the financing systems’ operation after reform corresponds with theories proved by case studies in other advanced states.

Performance and Permeability: An investigation of the Mashrabiya for Use within the Gibson Desert

<p>This study investigates a traditional Middle Eastern building element, the mashrabiya, and looks at the potential application of this device within the contemporary context of the Giles Weather Station in the Gibson Desert of Australia. The mashrabiya is a carved wooden screen used to control the fierce desert conditions of the Middle East. It created conditions of comfort within an extreme climate but is no longer prescribed due to the restrictive economic constraints involved with its construction. The research firstly considered the history of the mashrabiya and its various roles within the traditional Middle Eastern dwelling and then applied contemporary fabrication and design processes to its construction. The use of a CNC mill to construct the screen revealed new variables and opportunities for their manipulation, thereby providing for new design possibilities which transform the way in which it controls the desert conditions. The result was substantial improvements in cost, performance and versatility of the screen. Due to this program of research the mashrabiya was able to be applied to the Giles Weather Station in a much more ambitious manner than would otherwise have been possible. As a result of this the weather station aims to be architecturally unique, both in appearance and in functional performance.</p>

Performance and Permeability: An investigation of the Mashrabiya for Use within the Gibson Desert

<p>This study investigates a traditional Middle Eastern building element, the mashrabiya, and looks at the potential application of this device within the contemporary context of the Giles Weather Station in the Gibson Desert of Australia. The mashrabiya is a carved wooden screen used to control the fierce desert conditions of the Middle East. It created conditions of comfort within an extreme climate but is no longer prescribed due to the restrictive economic constraints involved with its construction. The research firstly considered the history of the mashrabiya and its various roles within the traditional Middle Eastern dwelling and then applied contemporary fabrication and design processes to its construction. The use of a CNC mill to construct the screen revealed new variables and opportunities for their manipulation, thereby providing for new design possibilities which transform the way in which it controls the desert conditions. The result was substantial improvements in cost, performance and versatility of the screen. Due to this program of research the mashrabiya was able to be applied to the Giles Weather Station in a much more ambitious manner than would otherwise have been possible. As a result of this the weather station aims to be architecturally unique, both in appearance and in functional performance.</p>