Time and Cost Interdependence in Water Supply System Construction Projects

Abstract

Time and price of contracted construction as well as their overrun are among highly pronounced issues in the construction practice. Numerous studies indicate that there is a dependency between these parameters at various construction markets. The paper shows the results of a research conducted on a group of 40 projects related to water supply systems carried out in the Federation of Bosnia and Herzegovina from 2001 to 2012. Collected data, obtained through interviewing chief engineers of construction companies, have been used as input parameters for implementation of single linear regression by applying the BTC (Bromilow time-cost) algorithm. The final result is a model in the form of an exponential equation. Whereas it was obtained based on effectuated values, it can be considered appropriate for assessing and testing the construction time in the early planning stage, as well as at work contracting. Since the parameter values in the model depend on circumstances of the specific area under consideration, the application of the model is recommended primarily in the area where the research was conducted. Results of the price overrun and construction overrun interdependence have not resulted in determining the exponential model. The paper also proposes application recommendations and guidelines for further research.

Implementation of Process‐Based and Data‐Driven Models for Early Prediction of Construction Time

“…Y is a construction time, X is a construction price, a is a parameter that expresses the average time needed for construction of a monetary value, and b is a model parameter that expresses the dependence of the time on the cost change [54]. is model has been tested, verified, and confirmed by many authors from many different countries around the world [13][14][15]25]. According toŽujo et al [13], one of the significant "time-cost" model limitations is that it can be applied only in the area or country of its origin because of specific economic characteristics, which are reflected on the value of model constants.…”

“…During the construction period, the construction time is influenced by changes of its determining factors. us, many construction projects have not met the contracted time and have been finished with significant construction time overrun [6,[8][9][10][11][12][13][14][15][16][17]. Consequently, reaching the contracted construction time is an important problem worldwide.…”

“…As stated in [13], Bromilow, from Australia, was the first who investigated time and financial execution for buildings constructed in Australia between 1963 and 1967. Using simple linear regression analysis as the mathematical method, the research resulted in establishing the so-called "time-cost" model or BTC model: Y � aX b , where Y is the construction time, X is the construction price, and a and b are constants.…”

Construction costs forecasting: comparison of the accuracy of linear regression and support vector machine models

“…They developed two type of models: for industrial projects and for projects that are not industrial. Similarly, other authors [14] investigated the correlation between time and cost overruns by applying the Bromilow's timecost algorithm.…”

“…They have investigated different aspects of construction costs such as: costs estimation, costs forecasting, costs overruns, the relation cost-time etc. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29].…”