Variability of Methodical Use of System Models for Determining the Cost in Construction

2017 ◽  
Vol 22 ◽  
pp. 62-66
Author(s):  
Elena Bondar ◽  
Vlad Stitsenko

This article presents a possibility of system-based implementation of determining the cost of work in construction. Based on the principles of systemic and variable visibility a logistics mechanism of the use of systemic economic and mathematical models for determining the cost of work in construction is proposed. The proposed mechanism includes specific regulatory features, contractual proposals and specific features of construction projects. The abovementioned methodology is based on a systemic synthesis of economic feasibility and technological complexity of construction work.

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.


2014 ◽  
Vol 13 (4) ◽  
pp. 357-364
Author(s):  
Agnieszka Dziadosz ◽  
Oleg Kapliński ◽  
Mariusz Rejment

The Earned Value Method allows the prediction of future values of the total cost and duration of the construction project realization, and also it allows the early detection of the collisions between the schedule and the construction project budget. It is more often indicated its usefulness for monitoring and controlling the construction work progress in the time and cost formulation. It is used, in the indirect way, to control the risk in terms of the cost overruns of the construction project realization and in case of the failure to meet the deadline for completion of the construction project. The authors’ goal was not only to indicate the advantages of the method (widely discussed in the literature) but also to indicate some inaccuracies in the application of the Earned Value Method, which may affect the costs forecasting and the date of completion of the construction project. The conclusions are based on the analysis of several construction project realizations.


Author(s):  
Naoto Mine ◽  
Soon Han Wai ◽  
Ting Chuan Lim

Formwork is one of the essential elements of construction work in traditional reinforced concrete building construction. In addition to being complicated work, formwork is labor intensive and requires numerous, highly-skilled formwork carpenters. Labor accounts to over 50% of the cost of formwork, a large percentage relative to other types of basic construction work. To increase formwork efficiency, it is necessary to improve work methods. While productivity of formwork has been the focus of previous studies, effective work data such as detailed work processes or man-hours were not sufficiently obtained. This paper reports on an observational study carried out on fifteen building construction projects using work-study techniques, specifically work processes, man-hours, and number of workers in each work process. It highlights the process analyses of a typical formwork construction project and discusses the results of a statistical analysis of labor productivity related to all construction projects.


2017 ◽  
Vol 5 (2) ◽  
pp. 80-96
Author(s):  
Raid Saleem Abd Ali ◽  
Nooran kanaan Yassin

This research aims to diagnose and identify the causes of claims and disputes between the contractor and the employer, also review the methods used to resolve disputes in construction contracts. In order to achieve the goal of the research, scientific methodology is followed to collect information and data on the subject of claims and disputes in construction projects in Iraq through personal interviews and questionnaire form. The most important results in this research are: the price schedule contract as a kind of competitive contracts is the most important and guarantee for the completion of minimum level of claims and disputes with relative importance of (84.1), compared with the (cost plus a percentage of the cost contract) as a kind of negotiating contracts is the most relative importance of (79.6), and the turnkey contract as a kind of special contracts is the most relative importance of (74.2). The  contractor and  his agents are one of the most influence sources in occurring claims and disputes in construction contracts with relative importance of (77.4) followed by the contract documents with relative importance of (74.2) and then the employer with relative importance of (73.2). In addition to the long period of litigation and the multiplicity of veto grades are most negative when contractual disputes have resolved by it, and with relative importance of (86), followed by the large number of issues and lack of efficiency and specialty of Judges with relative importance (78.4). Finally, the direct negotiation method (relative importance of 77) is one of the most friendly settlement ways favored by conflicted parties, while the resolution of disputes and claims board (relative importance of 10) occupied the last rank in the friendly settlement ways.


Author(s):  
Anastasiya V. Mironova ◽  
Igor’ V. Liskin ◽  
Irina I. Afonina

Neglect of soils leads to their degradation, worsens useful properties, and reduces fertility and productivity. (Research purpose) The research purpose is in conducting a comparative analysis of technologies for treating degraded soils, taking into account the economic feasibility of their restoration in non-black-soil regions of Russia. (Materials and methods) The article shows the main technological scheme of restoration of degraded soils. Authors have identified the main groups of land that are located in non-black-soil regions of Russia. (Results and discussion) The article presents the need for equipment, economic and labor costs for the restoration of each type of land in the non-black-soil regions of Russia. Authors took into account that the salary of machine operators depends on the time of direct execution of the task. It was found that the restoration of virgin and fallow lands was the most preferable from the economic, energy-saving and environmental points of view. The article shows that the restoration of pasture areas exceeds the cost of processing virgin lands, but the number of necessary machine and tractor units is comparable to work on virgin lands. Authors recommend to develop the soils with woody and shrubby vegetation in the first place, starting with land occupied by young plants. It is necessary to take into account the criteria for the fertility of the soil layer. It was found that soils with a small excess of moisture have small cost of its development, while on heavily swampy soils the cost of work on their development is many times higher than the cost of restoring other types of land. (Conclusion) The article shows that the restoration of neglected land is a necessary condition for improving the provision of human needs for food and a number of industrial goods. First of all, it is necessary to develop land that requires minimal investment of economic and labor costs.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jon Kepa Izaguirre ◽  
Leire Barañano ◽  
Sonia Castañón ◽  
José A. L. Santos ◽  
M. Teresa Cesário ◽  
...  

AbstractThe management of municipal solid waste is a major logistic and environmental problem worldwide. Nonetheless, the organic fraction of municipal solid waste (OFMSW) is a valuable source of nutrients which can be used for a variety of purposes, according to the Circular Economy paradigm. Among the possible applications, the bioproduction of a biodegradable polyester, poly(3-hydroxybutyrate) [P(3HB)], using OFMSW as carbon platform is a promising strategy. Here, an economic and environmental assessment of bacterial P(3HB) production from OFMSW is presented based on previously published results. The SuperPro Designer® software was used to simulate P(3HB) production under our experimental parameters. Two scenarios were proposed depending on the fermentation medium: (1) enzymatic hydrolysate of OFMSW supplemented with glucose and plum waste juice; and (2) basal medium supplemented with glucose and plum waste juice. According to our results, both scenarios are not economically feasible under our experimental parameters. In Scenario 1, the low fermentation yield, the cost of the enzymes, the labour cost and the energy consumption are the factors that most contribute to that result. In Scenario 2, the cost of the extraction solvent and the low fermentation yield are the most limiting factors. The possibility of using process waste as raw material for the generation of other products must be investigated to enhance economic feasibility. From an environmental viewpoint, the photochemical oxidation potential (derived from the use of anisole as extraction solvent) and the generation of acid rain and global warming effect (caused by the burning of fuels for power generation) are the most relevant impacts associated to P(3HB) production under our experimental parameters.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110196
Author(s):  
Brendon Mpofu ◽  
Hembe E Mukaya ◽  
Diakanua B Nkazi

Carbon dioxide has been identified as one of the greenhouse gases responsible for global warming. Several carbon capture and storage technologies have been developed to mitigate the large quantities of carbon dioxide released into the atmosphere, but these are quite expensive and not easy to implement. Thus, this research analyses the technical and economic feasibility of using calcium leached from cow bone to capture and store carbon dioxide through the mineral carbonation process. The capturing process of carbon dioxide was successful using the proposed technique of leaching calcium from cow shinbone (the tibia) in the presence of HCl by reacting the calcium solution with gaseous carbon dioxide. AAS and XRF analysis were used to determine the concentration of calcium in leached solutions and the composition of calcium in cow bone respectively. The best leaching conditions were found to be 4 mole/L HCl and leaching time of 6 h. Under these conditions, a leaching efficiency of 91% and a calcium conversion of 83% in the carbonation reaction were obtained. Other factors such as carbonation time, agitation rate, and carbonation reaction temperature had little effect on the yield. A preliminary cost analysis showed that the cost to capture 1 ton of CO2 with the proposed technique is about US$ 268.32, which is in the acceptable range of the capturing process. However, the cost of material used and electricity should be reviewed to reduce the preliminary production cost.


2015 ◽  
Vol 61 (1) ◽  
pp. 147-161 ◽  
Author(s):  
M. Połoński

AbstractThe paper presents methods of determining the location of cost buffers and corresponding contingency costs in the CPM schedule based on its work breakdown structure. Application of correctly located cost buffers with appropriately established reserve costs is justified by the common overrunning of scheduled costs in construction projects. Interpolated cost buffers (CB) as separate tasks have been combined with relevant summary tasks by the start–to–start (SS) relationship, whereas the time of their execution has been dynamically connected with the time of accomplishment of particular summary tasks using the “paste connection” option. Besides cost buffers linked with the group of tasks assigned to summary tasks, a definition of the cost buffer for the entire project (PCB) has been proposed, i.e. as one initial task of the entire project. Contingency costs corresponding to these buffers, depending on the data that the planner has at his disposal, can be determined using different methods, but always depend on the costs of all tasks protected by each buffer. The paper presents an exemplary schedule for a facility and the method of determining locations and cost for buffers CB and PCB, as well as their influence on the course of the curve illustrating the budgeted cost of work scheduled (BCWS). The proposed solution has been adjusted and presented with consideration of the possibilities created by the scheduling software MS Project, though its general assumptions may be implemented with application of other similar specialist tools.


2011 ◽  
Vol 480-481 ◽  
pp. 1197-1200
Author(s):  
Feng Liu ◽  
Jun Min Wang

In recent years, in order to reduce building energy consumption in China, and vigorously promote the development of ecological construction, the paper studies disadvantages of the cost of traditional project management applications in the ecological construction projects, exploring specific cost management adapt to the ecological construction project.


Sign in / Sign up

Export Citation Format

Share Document