Abstract
This paper presents the results of predicting the failure rate of water distribution pipes and house connections in a selected city in Poland by means of regression trees. Several regression tree models were built as part of modelling. Optimal models were selected (separately for each of the water conduit types) via an analysis of the so–called costs. The regression tree structure comprised independent variables, i.e. predictors (length, diameter, year of construction and material). The failure rates of the two types of water conduits were the dependent variable. The optimal models were characterized by the lowest costs and a relatively simple tree architecture. Operational data from the years 2001–2012 were used to determine the experimental (real) values of the failure rate and to build regression tree models. The optimal models included eight divided nodes and nine end nodes. The ranking of the significance of the parameters showed that length was the predictor responsible for division on the successive tree levels. The obtained high consistency (0.99) of the real data with the predicted ones indicates that the regression tree method can be used to analyze and assess the failure rate of water conduits.
Highlights
Mathematical modelling has been applied in many spheres of life already for many years [1, 2]
It should be mentioned that regression trees can be connected into assemblies of trees to form a random forest
This is naturally limited by the acquirability of many operational variables. It seems that information on the pressure prevailing in the water supply network and other data on the pipelines and even data seemingly not connected with the failure rate problem, such as water production and demand or losses, should be added to the vector of predictors
Summary
Mathematical modelling has been applied in many spheres of life already for many years [1, 2]. The regression tree methodology has not been widely used to assess the reliability of municipal system operation or to predict selected indicators This is why the author decided to take up this subject. The main aim of this paper is to show the possibilities of applying the regression tree algorithm to the analysis of the frequency of failures of water conduits. This method has already found application in many other fields, e.g. in the assessment of the degree of damage to buildings [17], in the modelling of the rate of failure of pumping systems [18] and in broadly understood economy [19]. It seemed worthwhile to find out whether it is suitable for assessing the frequency of failures of water supply networks
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
