Optimization-based Approach for Organizing the Bidding of Nonserial Repetitive Projects (original) (raw)
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Time and finance optimization model for multiple construction projects using genetic algorithm
Journal of the Mechanical Behavior of Materials, 2022
Construction contractors usually undertake multiple construction projects simultaneously. Such a situation involves sharing different types of resources, including monetary, equipment, and manpower, which may become a major challenge in many cases. In this study, the financial aspects of working on multiple projects at a time are addressed and investigated. The study considers dealing with financial shortages by proposing a multi-project scheduling optimization model for profit maximization, while minimizing the total project duration. Optimization genetic algorithm and finance-based scheduling are used to produce feasible schedules that balance the finance of activities at any time with the available funds. The model has been tested in multi scenarios, and the results are analyzed. The results show that negative cash flow is minimized from −693,784 to −634,514 in enterprise I and from −2,646,408 to −2,529,324 in enterprise II in the first scenario and also results show that negative cash flow is minimized to −612,768 with a profit of +200,116 in enterprise I and to −2,597,290 with a profit of +1,537,632 in enterprise II in the second scenario.
Automated trade-off between time and cost in planning repetitive construction projects
Construction Management and Economics, 2009
An automated model is developed to support the optimization of the planning and scheduling of repetitive construction projects. The model provides the capability of optimizing two important objectives commonly sought in scheduling repetitive construction projects: minimizing project duration; and minimizing project cost. The model performs this multi-objective optimization using a genetic algorithm approach. The output of the model is a set of optimal solutions that represent the trade-off between time and cost in planning repetitive construction projects. Furthermore, the model can be utilized to find a single scheduling solution that provides the minimum overall project cost by simply adding project indirect cost to the obtained project direct cost for each of the obtained scheduling solutions on the Pareto optimal curve. Other important time-related costs are also considered in the model including: early completion incentives, late completion penalties and lane rental costs. Providing the planners of repetitive construction projects with an automated set of optimal time-cost trade-off solutions should contribute to cost-effective and speedy delivery of this type of construction project. An application example is analysed to illustrate the use of the model and demonstrate its capabilities in generating optimal trade-off solutions between minimizing the project time and cost for repetitive construction projects.
Scheduling and Cost Optimization of Repetitive Projects Using Genetic Algorithms
Repetitive construction projects occupied large space in construction industry. Repetitive projects characterized by high cost, long duration and utilization of many expensive resources. So, effective planning and scheduling of repetitive projects is very important in order to save time and cost. In this paper a flexible and dynamic model for scheduling and optimization of repetitive projects is presented. The model encompasses two modules: a resource-driven scheduling module; and an optimization module. The advantages of the model stem from the following main characteristics: 1) it considers typical and atypical repetitive activity, 2) it uses multiple crews and assigns available crew to next units, 3) it considers different construction methods for each activity, 4) it maintains work continuity, 5) it allows for activity interruption, 6) it incorporates a genetic algorithm procedure to search for the optimum schedule that minimizes total project cost, and 7) it presents outputs in both tabular and graphical formats. The model is allowing the user to experiment with several combinations of construction methods that produce different plans by changing the construction methods indices manually. The objective of the optimization part is to minimize total construction cost which comprises direct cost, indirect cost and interruption cost. The optimization part allows the user to produce several optimal plans and choose among them the best for his target project. Based on the proposed model, a computerized system for scheduling of repetitive project was developed. Details of model development and implementation are described, and an example application is presented to demonstrate the capabilities of the developed system.
A Multi-objective Model for Optimizing Construction Planning of Repetitive Infrastructure Projects
This paper presents the development of a model for optimizing resource utilization in repetitive infrastructure projects. The model provides the capability of simultaneous minimization of both project duration and work interruptions for construction crews. The model provides in a single run, a set of nondominated solutions that represent the tradeoff between these two objectives. The model incorporates a multiobjective genetic algorithm and scheduling algorithm. The model initially generates a randomly selected set of solutions that evolves to a near optimal set of tradeoff solutions in subsequent generations. Each solution represents a unique scheduling solution that is associated with certain project duration and a number of interruption days for utilized construction crews. As such, the model provides project planners with alternative schedules along with their expected duration and resource utilization efficiency.
Cost Optimization of Projects with Repetitive Activities Using Genetic Algorithms
Proceedings of the Sixth International Conference on Engineering Computational Technology, 2008
Scheduling of construction projects which have multiple units, wherein activities repeat from unit to another, always represent a major challenge to project managers. These projects require schedules that ensure the uninterrupted usage of resources from one unit to another and maintaining logic constraints at the same time. Such projects occupy large space in construction industry and they are characterized by high cost, long duration and utilization of many expensive resources. So, effective planning and scheduling of repetitive projects is very important in order to save time and cost. In this paper, a proposed method is introduced to schedule repetitive projects with the objective of optimizing the project total cost which comprises direct, indirect and interruption costs. The proposed model encompasses two modules: a resource-driven scheduling module; and an optimization module. The proposed model considers both typical and atypical repetitive activities; uses multiple crews and assigns available crew to next units; considers different construction methods for each activity; maintains work continuity; and allows for activity interruption. A genetic algorithm optimization module is used to search for the optimum schedule that minimizes total project costs. Details of model development and implementation are described along with a real life case study to demonstrate the practicality and the capabilities of the developed.
Tehnicki vjesnik - Technical Gazette
The purpose of this study is to develop a genetic algorithm (GA) based software that can perform resource allocation close to optimum and that can determine the critical path by minimizing the project duration according to the resource profile for a present work schedule and resource pool using a programmable objective function. In this context, the methodology of GAs was presented, the software was developed and the performance of this software was tested with a sample project. With the developed software, by minimizing the activity durations in both constrained and unconstrained resource conditions, projects can be scheduled, total duration and the critical path of the projects can be determined. With this software, any construction company will be able to determine how much time would be required to complete a project at the bidding stage by considering its resources and constraints and can take the required precautions. The main difference of this present study is that the developed code performs minimization of schedule duration integrated with resource allocation and levelling. It also determines the critical path of the final solutions. Both renewable and non-renewable resources are included in the code which is not often considered in the literature. By minimizing project duration and optimizing resource allocation, construction projects can become more sustainable, and the environmental impact of the construction process could be minimized.
Cost-Time Optimization of a Construction project using Genetic-Algorithm approach
International Journal of Scientific Research in Science, Engineering and Technology, 2023
People's daily necessities are provided for both directly and indirectly by the construction sector. A construction project often entails the use of various resources (such as equipment, materials, labour, etc.) to create a finished product (such as a building, a bridge, a water distribution system, etc.) that meets the needs of the intended consumers. Budget restrictions, contractual time restrictions, safety and health concerns, sustainability ratings, local building rules, and the desired degree of quality are just a few of the challenges faced in construction projects. As a result, there are several goals for a construction project, including maximum productivity, lowest cost, shortest duration, and specified quality, safety, and sustainability. When attempting to combine multiple objectives into the best possible answer, decision-making can be challenging. In this thesis, a GA model with 152 decision variables, 462 constraints, and 361 optimal solutions was suggested. This study suggests dynamic programming-based GA for equipment management issues because we thought it would be able to address these issues more effectively than conventional approaches. The method's objectives were to reduce overall project costs and increase equipment performance so that, in the event of equipment failure, backup equipment would be accessible. Furthermore, it was decided to treat the equipment failure rate as a fuzzy variable to increase the method's dependability. The model was put to the test using a real hydroelectric project in India. The new approach outperformed the conventional methods in searching in the same environment.
Genetic Algorithm Based Optimization Model for Time-Cost Trade-Off for Construction Project
International Journal for Research in Applied Science & Engineering Technology (IJRASET), 2023
The main cause of gradual development of project management is the necessity of controlling and optimizing the construction project's objectives. In planning phase of construction project management, some objectives of proposed project are required to be set as per stakeholder's perspective. Time and cost are of paramount importance objectives of construction project, which vary due to variation in the resource utilization amount. High-cost resources and advance technologies reduce the project time but make the project cost higher. While low-cost resources and traditional technologies give lower project cost but increase the project time. Basically, a construction project is said to be successful if it is completed in minimum possible time and cost. Therefore, the two fundamental goals of any building project are to do it as quickly and inexpensively as possible. The development of time-cost trade-off models has received a lot of focus. However, in addition to a wide range of approaches for time-cost trade-off (TCT) models, this work offers a TCT model based on a genetic algorithm. This model was created in a way that makes it easier to find the best approaches to complete the project on time and for the lowest possible cost. The applicability of proposed TCT model is demonstrated through solving two practically existing construction project. Outcomes of proposed model were found satisfactory based on statistical analysis.
Resource-Constrained Time-Cost Tradeoff for Repetitive Construction Projects
KSCE Journal of Civil Engineering, 2019
The time-cost tradeoff problem is to find optimal combinations of construction options with the objective of minimizing project time and cost. In order to search for such a set of optimal solutions, the total time and cost of projects needs to be calculated properly. In repetitive construction projects (RCPs), due to division of work into several units and involvement of many resources for activities completion, scheduling is unique and more complicated. Scheduling method in this paper besides addressing common constraints such as precedence relationships, required lead time and lag distance between activities, enables project managers to consider all resources and their shortages in scheduling. To raise the practicality of model, in addition to direct and indirect costs, resource idle cost is considered as a cost element in estimating total cost of project. The time variant multi-objective particle swarm optimization is applied to find non-dominated solutions on the basis of minimizing time and cost of project. An application example is presented at the end to illustrate the performance of the model. This research presents a resource-constrained time-cost tradeoff model to find the optimal set of crew combinations for project activities in RCPs, considering time and cost simultaneously.
Financing - Scheduling Optimization For Construction Projects By Using Genetic Algorithms
2011
Investment in a constructed facility represents a cost in the short term that returns benefits only over the long term use of the facility. Thus, the costs occur earlier than the benefits, and the owners of facilities must obtain the capital resources to finance the costs of construction. A project cannot proceed without an adequate financing, and the cost of providing an adequate financing can be quite large. For these reasons, the attention to the project finance is an important aspect of project management. Finance is also a concern to the other organizations involved in a project such as the general contractor and material suppliers. Unless an owner immediately and completely covers the costs incurred by each participant, these organizations face financing problems of their own. At a more general level, the project finance is the only one aspect of the general problem of corporate finance. If numerous projects are considered and financed together, then the net cash flow requirem...