Optimizing the Prefabrication Finishing Level in Modular Construction

Author(s):  
Mohammad Almashaqbeh ◽  
Khaled El-Rayes

Prefabricated modules in modular construction projects can have a wide range of finishing levels that range from partially completed with only structural frame to fully completed with all structural, wall, mechanical, electrical, finishing and furnishing components. A higher module finishing level increases the offsite fabrication and transportation cost and decreases onsite assembly cost and duration while a lower finishing level produces the opposite results. This paper presents an optimization model that enables construction planners to identify an optimal finishing level for prefabricated modules in order to minimize the total cost of modular construction projects that includes all offsite fabrication, transportation, and onsite assembly costs. A case study of a modular construction project for a healthcare facility was analyzed to illustrate the use of the model and evaluate its performance. The results of this analysis highlight the original capabilities of the model in minimizing the total cost of modular construction projects.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Almashaqbeh ◽  
Khaled El-Rayes

PurposeThe objective of this research study is to formulate and develop a novel optimization model that enables planners of modular construction to minimize the total transportation and storage costs of prefabricated modules in modular construction projects.Design/methodology/approachThe model is developed by identifying relevant decision variables, formulating an objective function capable of minimizing the total transportation and storage costs and modelling relevant constraints. The model is implemented by providing all relevant planner-specified data and performing the model optimization computations using mixed-integer programming to generate the optimal solution.FindingsA case study of hybrid modular construction of a healthcare facility is used to evaluate the model performance and demonstrate its capabilities in minimizing the total transportation and onsite storage costs of building prefabricated modules.Research limitations/implicationsThe model can be most effective in optimizing transportation for prefabricated modules with rectangular shapes and might be less effective for modules with irregular shapes. Further research is needed to consider the shape of onsite storage area and its module arrangement.Practical implicationsThe developed model supports construction planners in improving the cost effectiveness of modular construction projects by optimizing the transportation of prefabricated modules from factories to construction sites.Originality/valueThe original contributions of this research is selecting an optimal module truck assignment from a feasible set of trucks, identifying an optimal delivery day of each module as well as its location and orientation on the assigned truck and complying with relevant constraints including the non-overlap of modules on each truck, shipment weight distribution and aerodynamic drag reduction.


2017 ◽  
Vol 10 (1) ◽  
pp. 5-31 ◽  
Author(s):  
Anna-Maija Hietajärvi ◽  
Kirsi Aaltonen ◽  
Harri Haapasalo

Purpose The effective management of inter-organizational integration is central to complex projects. Such projects pose significant challenges for integration, as organizations struggle with constantly changing inter-organizational interdependencies and must develop and adapt integration mechanisms to meet new demands. The purpose of this paper is to understand what kinds of integration mechanisms are used and how they are developed and adjusted during the infrastructure alliance projects. Design/methodology/approach This study provides empirical evidence of integration dynamics in project alliancing by analyzing two infrastructure alliance projects – a complex tunnel construction project and a railway renovation project. The research approach is an inductive case study. Findings This paper identifies integration mechanisms adopted in two case projects and three central triggers that led to changes in the integration mechanisms: project lifecycle phase, unexpected events and project team’s learning during the project. Practical implications Integration capability should be a precondition for alliance project organizations and requires the adoption of a wide range of integration mechanisms, as well as an ability to adjust those mechanisms in response to everyday dynamics and emergent situations. Originality/value Although unplanned contingencies and the responses to them represent important influences in organizations, there is limited amount of research on the dynamics of integration. The findings will be of value in supporting the management of inter-organizational integration in complex, uncertain and time-critical construction projects.


2021 ◽  
Vol 27 (1) ◽  
pp. 45-59
Author(s):  
Hong Zhang ◽  
Lu Yu

Delivery of the prefabricated components may be disrupted by low productivity and various of traffic restrictions, thus delaying the prefabricated construction project. However, planning of the prefabricated component supply chain (PCSC) under disruptions has seldom been studied. This paper studies the construction schedule-dependent resilience for the PCSC plan by considering transportation costs and proposes a multi-objective optimization model. First, the PCSC planning problem regarding schedule-dependent resilience and resultant transportation cost is analyzed. Second, a quantification scheme of the schedule-dependent resilience of the PCSC plan is proposed. Third, formulation of the resilience-cost tradeoff optimization model for the PCSC planning is developed. Fourth, the multi-objective particle swarm optimization (MOPSO)-based method for solving the resilience-cost tradeoff model is presented. Finally, a case study is presented to demonstrate and justify the developed method. This study contributes to the knowledge and methodologies for PCSC management by addressing resilience at the planning stage.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Kang Zhou ◽  
Shiwei He ◽  
Rui Song ◽  
Xiaole Guo ◽  
Kaiming Li

Relying on the express freight network, the dispatching of empty pallets based on the pallet pool mode is studied to reuse pallets with the minimum transport cost, enhance the pallet utilization rate, reduce the waste of resources, and save the cost of logistics. Considering the influence of transport efficiency for different modes in transportation process, differences of transportation cost, carbon emissions, and transportation timeliness of demand points required, an optimization model is constructed. The objective of the model is to minimize the total cost including transportation cost, inventory cost, lease cost, and loss cost. According to the structural characteristics of the model, genetic algorithm and improved cloud clonal selection operation is used to solve the model. Finally, the validity and rationality of the optimization model are verified by a case study. The result shows that the total dispatching cost of considering time requirement is 1.8 times the cost without considering the time requirement, respectively, both less than the total cost of pallets leasing. Moreover, when there are 3 supply points and 2 demand points and the number of iterations is 100, after the algorithms are run for 30 times, the worst values are 9305 and 8317 for genetic algorithm and the improved cloud clonal selection operation, respectively. Therefore, the efficiency of the improved cloud clonal selection operation is higher than genetic algorithm.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Ce Zhao ◽  
Lixing Yang ◽  
Shukai Li

This paper investigates the freight empty cars allocation problem in railway networks with dynamic demands, in which the storage cost, unit transportation cost, and demand in each stage are taken into consideration. Under the constraints of capacity and demand, a stage-based optimization model for allocating freight empty cars in railway networks is formulated. The objective of this model is to minimize the total cost incurred by transferring and storing empty cars in different stages. Moreover, a genetic algorithm is designed to obtain the optimal empty cars distribution strategies in railway networks. Finally, numerical experiments are given to show the effectiveness of the proposed model and algorithm.


2020 ◽  
Vol 1 (1) ◽  
pp. 2-21
Author(s):  
Christopher Rausch ◽  
Chloe Edwards ◽  
Carl Haas

Dimensional quality plays a key role in project success for modular construction. While approaches exist for reducing rework associated with dimensional variability in traditional construction (i.e., onsite resolution), more proactive approaches must be employed during offsite production of modules. Unfortunately, the stricter dimensional quality demands in modular construction are not yet completely addressed in existing guidelines or studies. As such, contractors often must resort to use of reactive measures to reduce rework. This paper bridges this gap by demonstrating how to implement continuous benchmarking and improvement of dimensional quality by comparing as-built and nominal 3D geometric data across modular construction projects. A case study is presented for two nearly identical modular construction projects, which are carried out in succession. The first project is used to quantify and benchmark key impacts on overall dimensional quality, while strategic improvements are introduced in the second project to improve quality and reduce rework. The results of this study demonstrate how contractors can achieve adequate dimensional quality and reduce rework on successive modular construction projects.


2013 ◽  
Vol 16 (1) ◽  
pp. 59-67

<p>The Soil Science Institute of Thessaloniki produces new digitized Soil Maps that provide a useful electronic database for the spatial representation of the soil variation within a region, based on in situ soil sampling, laboratory analyses, GIS techniques and plant nutrition mathematical models, coupled with the local land cadastre. The novelty of these studies is that local agronomists have immediate access to a wide range of soil information by clicking on a field parcel shown in this digital interface and, therefore, can suggest an appropriate treatment (e.g. liming, manure incorporation, desalination, application of proper type and quantity of fertilizer) depending on the field conditions and cultivated crops. A specific case study is presented in the current work with regards to the construction of the digitized Soil Map of the regional unit of Kastoria. The potential of this map can easily be realized by the fact that the mapping of the physicochemical properties of the soils in this region provided delineation zones for differential fertilization management. An experiment was also conducted using remote sensing techniques for the enhancement of the fertilization advisory software database, which is a component of the digitized map, and the optimization of nitrogen management in agricultural areas.</p>


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