A new mathematically based model for forecasting construction project expenditure pattern.
This research explores the viable use of'S' curve models for simulating construction
project expenditure patterns.
The research establishes a new approach to the classification of the current models,
based on the analysis of their structure. This requires the identification of the
parameters comprising the mathematical expression of the model, the attributes of
the suhject matter contained in the data, and the mechanism facilitating the link
between these two components. The latter is established through the analysis of the
'shape' of the construction project expenditure profiles which have been shown to
contain certain characteristics. Some of these characteristics comply with the law of
growth and are 'general' for all construction projects while other characteristics are
'specific' and distinguish one project from another.
Subsequent to the above, the research identifies the need for the development of a
new improved mathematical model. This process involves the development of a new
mathematical expression comprising three modules; the Control module which
maintains control over the properties of the underlying expenditure pattern, the
Distortion module which facilitates simulation of any distortion on the underlying
pattern, and the Kurtosis module which controls the rate of growth at the beginning
and end portions of the expenditure curve.
The above modules are simulated by an exponential and two fourth degree
polynomial equations respectively. The simulation is carried out by identifying the
values of the variables relating to the characteristic 'shape' ofthe expenditure pattern,
namely, the dependent-variables. These variables are provided either directly by the
user or they can be estimated by utilising the appropriate dependent-variable model.
These models which are the product of statistical analysis of a large quantity of
hl.;torical data, have been developed for a variety of categories of construction
This research, therefore, proposes a new mathematical model for simulating
construction project expenditure patterns, thereby, provide an effective financial
management tool. The model combines many of the advantageous features contained
in a variety of existing models, namely, ease of use, user involvement and appreciation
of the underlying logic of forecasting, and ability to generate a forecast at an early