scholarly journals Kajian Harga Bahan pada Proyek Konstruksi dengan Analisa Dinamik

2021 ◽  
Vol 28 (1) ◽  
pp. 117-124
Author(s):  
Diah Sarasanty

Abstrak  Konstruksi merupakan salah satu industri yang memberikan kontribusi secara signifikan terhadap pertumbuhan ekonomi suatu negara. Sebuah proyek konstruksi dikatakan berhasil apabila dalam pelaksanaannya memenuhi tiga komponen yakni biaya, waktu, dan mutu. Komponen biaya digunakan untuk studi kelayakan dan pemilihan desain yang optimal dalam sebuah proyek konstruksi. Ketidak akuratan dalam menganalisa biaya konstruksi dapat memberikan efek negatif pada seluruh proses konstruksi dan semua pihak yang terlibat. Penelitian ini bertujuan untuk menganalisa dinamika harga bahan pada proyek konstruksi. Tahapan metode yang dilakukan dalam penelitian ini yaitu dengan mengidentifikasi hubungan sebab akibat antar variabel dalam menganalisa harga bahan. Dari hasil simulasi diperoleh analisa secara grafis melalui keluaran model. Validasi model dilakukan dengan membandingkan base model dengan sebuah skenario. Hasil perhitungan analisa sensitivitas dari perbandingan memperoleh nilai mean comparison ≤ 5% dan variasi amplitudo error variance ≤ 30% yang mengindikasikan kevalidan model yang diusulkan. Dengan keakurasian tersebut diharapkan dapat mengakomodasi segala kemungkinan adanya penyimpangan yang akan terjadi dimasa depan termasuk faktor resiko, sehingga dapat menciptakan sistem yang sesuai dengan kinerja yang diinginkan dan sumber daya yang digunakan lebih efektif serta efisien dalam rangka mencapai sasaran proyek. Kata-kata Kunci: Harga bahan, dinamik, proyek konstruksi. Abstract  Construction is an industry that contributes significantly to a country's economic growth. A construction project is said to be successful if it fulfills three components, namely cost, time and quality. The cost component is used for a feasibility study and the optimal design selection in a construction project. Inaccuracy in analyzing construction costs can have a negative effect on the entire construction process and all parties involved. This study aims to analyze the dynamics of material prices in construction projects. The method used in this research is to identify the causal relationship between variables in analyzing the price of materials. From the simulation results obtained graphical analysis through the model output. Model validation is done by comparing the base model with a scenario. The results of the calculation of the sensitivity analysis from the comparison obtained a mean comparison value of ≤ 5% and the amplitude variation value of the variance error ≤ 30% which indicates the validity of the proposed model. With this accuracy it is expected to be able to accommodate all possible deviations that will occur in the future including risk factors, so as to create a system that is in accordance with the desired performance and the resources used more effectively and efficiently in order to achieve project goals. Keywords: Material cost, dynamic, construction project

2019 ◽  
Vol 25 (7) ◽  
pp. 687-699 ◽  
Author(s):  
Usama Hamed Issa ◽  
Salah Attia Mosaad ◽  
Mohamed Salah Hassan

Cost overruns and time delays are considered to be very important challenges for the majority of construction projects. These challenges are typically attributed to their associated risks. Due to the risky and uncertain nature of construction projects, an increasing amount of attention is given to estimating and overcoming cost overruns and time delays. New techniques are being developed to help project managers to contractually complete projects within cost and time constraints. The objective of this study was to develop a new qualitative and quantitative risk analysis model that can be employed for construction projects. The proposed model, which is based on a fuzzy logic tool, consists of two modules for assessing risk factors that affect the main construction activities and computing the expected cost overruns and time delays that are associated with these risks. Using numerous logical rules, the model applies the probability of occurrences and impacts of the risks on the cost and time of the main activities. The Spearman and Kendall correlation coefficient tests are applied to verify and select a suitable membership function. Using four proposed membership functions, the results of these tests confirmed that the triangle membership function is suitable for the model. The model is verified by application to HVAC system activities in two actual construction projects, which serve as case studies. Two different methods are proposed and applied to quantify the cost overruns and time delays. The first method is based on determining the cost overruns and time delay values for each activity according to their weight in the system. Triple premise rules are proposed and applied in the second method, which is established to relate all activities. The results from the second method are more accurate compared with the first method based on actual data from the case study projects. In addition, the results demonstrated that the proposed model can be used to quantify the expected cost overrun and time delays in construction project activities and can be generalized and implemented in different construction activities.


2019 ◽  
Vol 5 (1) ◽  
pp. 13-19
Author(s):  
Fitri Nur Kharina ◽  
Kusno Adi Sambowo

Construction projects in all regions continues to be developed for the creation of facilities that can be utilized by the community. One of them is the construction of apartments which are now being intensively carried out to meet residential needs for the community. Making a construction project plan always refers to estimates that exist at the time development plan is made, therefore problems can arise if there is a discrepancy between the plans that have been made and the actual reality. So the impact that often occurs is the delay in the time of project implementation which can also be accompanied by an increase in the cost of implementing the project. In the construction project of Cinere Terrace Suites Apartemen & Citywalk, Jakarta there was a delay resulting in a late payment of monthly bill progress by the owner. Based on the above reasons, this research was conducted to find out how the project performance was seen from the cost and time period of the review period. how is the estimated cost and time to complete the overall project work. The method used in the analysis of this study is the Earned Value Method. Based on the results of the analysis carried out for 29 weeks the project performance on schedule has been delayed and cost shows a positive value. For the estimated completion time of the project there is an increase in time whose duration increases from the planned 98 weeks or 685 days to 109,624 weeks or 768 days. While the estimated cost of completing the project from the results of the analysis obtained a value of Rp. 270,147,448,569.16 smaller than the planned cost of Rp. 315,272,727,272.73. With the difference VAC of Rp. 45,125,278,703.57 this shows that there are benefits obtained by the contractor.


2019 ◽  
Vol 258 ◽  
pp. 02027
Author(s):  
Hirijanto ◽  
I Wayan Mundra ◽  
Addy Utomo

Project’s cost is one of important components in project achievement. Because of the uniqueness of construction projects, cost estimation always differs from project to project. The rate of cost components always change over time make difficult to forecast the cost for the upcoming project. The cost component consists of many influencing variables where there is interrelationship each other affecting to the total project cost. This paper objective is to develop a cost prediction model to assist the project planners in cost estimation for future projects. System dynamic is one of the appropriate methods to analyse system behaviour with interrelationship referring to the historic data, so it is able to predict the future project. Developing the model, primary and secondary data are collected from previous studies, interview with the government planner and survey in Malang Regency. The model simulation is Brick work unit with its components. Data from last thirteen years are used to verify and validate the developed model by causal loop diagram as a basic method in system dynamic. The finding showed that the model is closed to real condition through the validation mechanism. The developed system is useful in decision making of budget planning based on work quantity.


Author(s):  
Sarah Fotouh ◽  
A. Samer Ezeldin

Optimization of resources is very important in all construction projects. Project managers have to face problems regarding management of cost, time and available resources for single projects. This is more challenging when managing multiple projects. Most of the recent studies focused on optimization of resources for a single project, or a single resource. This paper presents a numerical model of multiple resources optimization for multiple projects using Genetic Algorithm. Most of the companies in the construction industry optimize the resources for single projects only. However, with the presence of several mega projects in several developing countries running at the same time, there is a need for a model to enhance the efficiency of available resources, and decreases the fluctuation as much as possible and try to maximize the use of the available pool of resources. The proposed model is user friendly, and it can optimize up to nine resources in three different projects running at the same time. The model is used on the identified critical resources. It calculates the cost of each resource, minimize the cost of extra resources as much as possible and generate the schedule of each project within a selected overall program.


2021 ◽  
Vol 263 ◽  
pp. 05048
Author(s):  
Maria Bovsunovskaya

The study is devoted to substantiating the need to develop a cost controlling system in order to improve the efficiency of investors, developers, customers, general contractors, as well as representatives of the banking system who are directly involved in the implementation of investment and construction projects. The paper summarizes the innovations of the Ministry of Construction, Housing and Utilities of the Russian Federation in the field of determining the cost of construction at the stages of the life cycle of an investment and construction project, and suggests their adaptation to the activities of commercial customers. The factors of the rise in the cost of construction in the modern conditions of the investment and construction sphere are systematized, including topical issues of the rise in cost due to the increase in prices of building materials. The main risks arising from the implementation of the project associated with an increase in cost are highlighted. As the results of the study, stages of construction cost control with a description of their content and a system of cost controlling of an investment and construction project are proposed.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xingliang Du

Construction projects require a significant amount of money and other resources in order to carry them out in an effective way. Cost control is a critical step in ensuring the success of the project and increasing its value. Nowadays, the large-scale application of BIM technology has ushered a technical change in the development of construction projects, which has greatly increased the level and efficiency of project management. Due to BIM technology, the construction engineering quality is significantly improved which really helped in obtaining the social and economic benefits. However, the BIM technology in our country is started relatively late and the technical force is not strong enough; then correspondingly, we must deal with many problems in the process of developing and using BIM technology based projects. In view of the fact and to address this issue, this paper establishes a three-dimensional architectural model based on the relevant information and data of the construction project using the BIM technology. The proposed model optimizes the clustering of construction project information data and adaptively configures the whole life cycle process of the construction projects. In addition, the performance of the proposed system has been compared and tested with the other systems as well which shows how good the proposed system is, as compared to the other systems. Further, the proposed model makes the artificial intelligence efficiency of the project management better. The simulation results show that the model not only has good access and query capabilities but also greatly improves the intelligence level of the project management.


Author(s):  
Mega Waty ◽  
Hendrik Sulistio

A Change Order is a written and legal work order that changes the scope of the original contract, with compensation that has been agreed upon by the owner and the contractor. Changes can be in the form of adding or reducing the scope of work, changing materials, or changing schedules. Change Order causes the cost of contract items to swell, planning errors and negligence as well as changes in scope that can be reduced by sharpening planning results. The scope of research on road construction in Indonesia, especially in DKI Jakarta and Banten provinces. This study aims to determine the identification of change orders in road construction projects. Data obtained from real data on road construction projects from 2013-2018 on 16 road construction project packages in the form of road construction project addendum contracts. Based on the addendum contract, added work, less work, addition of new items and removal of work items are determined. The identification of change order risk is seen from three aspects, namely the addition and reduction of work items, the removal of items and the addition of new items and the wishes of the owner, thereby increasing the cost of the change order contract. This study found 732 changes in construction work items. Risk identification is obtained from the frequency of changes above 35% which is an intermediate frequency that tends to increase the occurrence of change orders. The results of risk identification were obtained for 31 construction work items, the highest percentage was for Thermoplastic Road Marking work, followed by 30 other construction work items. Keywords: risk identification; change orders; road construction projects  AbstrakChange Order adalah perintah kerja tertulis dan sah  yang mengubah lingkup kontrak semula, dengan kompensasi  yang sudah disetujui oleh pemilik dan  kontraktor.  Perubahan dapat berupa penambahan atau pengurangan lingkup pekerjaan, perubahan material, atau perubahan jadwal. Change Order menyebabkan biaya  item kontrak membengkak, kesalahan perencanaan dan kelalaian serta perubahan ruang lingkup yang dapat dikurangi dengan mempertajam hasil perencanaan.. Lingkup penelitian pada konstruksi jalan di Indonesia khususnya  provinsi DKI Jakarta dan Banten. Penelitian  bertujuan untuk  mengetahui  identifikasi change order proyek konstruksi jalan. Data didapat dari data riil proyek konstruksi jalan dari tahun 2013- 2018 pada 16 paket proyek konstruksi jalan berupa kontrak addendum proyek konstruksi jalan. Berdasarkan kontrak addendum maka ditentukan pekerjaan tambah, pekerjaan kurang, penambahan item baru dan penghilangan item pekerjaan. Identifikasi risiko change order dilihat dari tiga aspek yakni penambahan dan pengurangan item pekerjaan, penghilangan item dan penambahan item baru dan keinginan dari pihak owner sehingga meningkatkan biaya kontrak change order.  Penelitian ini mendapatkan 732 perubahan  item pekerjaan konstruksi.  Identifikasi risiko didapat dari  frekuensi perubahan diatas 35% yang merupakan frekuensi menengah yang cenderung meningkatkan terjadinya change order. Hasil identifikasi risiko didapat pada  31 item pekerjaan konstruksi, yang tertinggi persentase pada pekerjaan  Marka Jalan Termoplastik, diikuti 30 item pekerjaan konstruksi lainnya.


2021 ◽  
Vol 6 ◽  
pp. 159-175
Author(s):  
Nirmal Lawaju ◽  
Nabin Parajuli ◽  
Santosh Kumar Shrestha

Construction labor productivity is the most determinant of success of any construction project. Labor is considered as more variable and unpredictable cost component for the successful accomplishment of construction projects. The main aim of this research is to develop an artificial neural network (ANN) model to predict the production rate for brick masonry work by assessing the various factor affecting labor productivity. Out of forty-four factors selected from a literature review, the top thirteen factors were selected for model development after the questionnaire survey and ranking them based on Relative Importance Index (RII). The model was developed in Neurosolution version 7.1.1.1 using the various input data set collected from active construction site of brick masonry. 65% of data set were used for training, 20 % of data set were used for cross-validation and remaining 15 % of data set were used for testing. The error between actual productivity and estimated productivity was computed using Mean Square Error (MSE) which was 0.019 which verified that the estimated production rate was within an acceptable range. After the successful testing of model, a sensitivity analysis was performed to analyze the order of most influencing factors affecting labor productivity. The developed ANN model can be used for estimating the labor productivity of brick masonry work for any building construction project by incorporating the influence of selected parameters or factors.


2020 ◽  
Vol 10 (2) ◽  
pp. 97-123 ◽  
Author(s):  
Amin Mahmoudi ◽  
Mehdi Abbasi ◽  
Xiaopeng Deng ◽  
Muhammad Ikram ◽  
Salman Yeganeh

PurposeSelecting a suitable contract to outsource construction projects is an ongoing concern for project managers and organizational directors. This study aims to propose a comprehensive model to manage the risks of outsourced construction project contracts.Design/methodology/approachTo employ the proposed model, firstly, the types of contracts and risks in the organization should be identified, then, to prioritize the contracts, the identified risks are considered as criteria. After receiving the experts' opinions, the best–worst method (BWM) integrated with grey relation analysis (GRA) method was used to prioritize the contracts. BWM and GRA are multi-criteria decision-making methods with different approaches and applications. In the current study, BWM has been employed to calculate the weights of criteria because it has better performance than other methods such as the analytic hierarchy process (AHP). After calculating the weights of criteria, the GRA method has been utilized for ranking the alternatives.FindingsAccording to the results obtained from the case study, the cost plus award fee contract is the most suitable alternative for outsourcing construction projects. The proposed methodology can be practically applied through different types of the projects such as construction or “engineering, procurement and construction”.Originality/valueTo the best of our knowledge, this is the first time a conceptual model has been proposed to select an appropriate contract for construction projects. Also, for the first time, the BWM integrated with GRA method has been used to prioritize project contracts based on the potential risks. The proposed model can contribute to project managers for selecting a suitable contract with the least risk in construction projects.


2016 ◽  
Vol 22 (7) ◽  
pp. 967-978 ◽  
Author(s):  
Vahidreza YOUSEFI ◽  
Siamak HAJI YAKHCHALI ◽  
Mostafa KHANZADI ◽  
Ehsan MEHRABANFAR ◽  
Jonas ŠAPARAUSKAS

Despite broad improvements in construction management, claims still are an inseparable part of many con-struction projects. Due to huge cases of claim in construction industry, this study argues that claim management is a significant factor in construction projects success. In this study, the most possible causes of these emerging claims are identified and statistically ranked by Probability-Impact Matrix. Subsequently, by classifying claims in different cases, the most important ones are ranked in order to achieve a better understanding of claim management in each project. In this regard, a new index is defined, being able to be applied in a variety of projects with different time and cost values, to calculate the amount of possible claims in each project along with related ratios with respect to the cost and time of each claim. This study introduces a new model to predict the frequency of claims in construction projects. By using the proposed model, the rate of possible claims in each project can be obtained. This model is validated by applying it into fitting case studies in Iran construction industry.


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