Developing a knowledge based system for the valuation of variations on civil engineering works
The provision for variations in construction projects contracts has become the convention
to provide the much-needed flexibility during the course of construction. Yet variations
often lead to conflicts and disputes due to the different perceptions of the project
stakeholders. One of the most contentious issues is in interpreting the rules to value the
varied works. The need for a robust mechanism for the valuation of variations has been
articulated in many publications. In light of this, this research aimed to develop such a
mechanism and so eliminate or at least reduce conflicts and disputes in construction
projects, particularly on civil engineering works.
Initial investigation via a small-scale survey, corroborated the occurrence and significance
of variation events in construction projects in the UK, whilst further literature study
confirmed the valuation of variations as one of the main sources of conflicts and disputes.
Subsequent study developed a negotiation model, and frameworks for valuing variations in
excavation works and concrete works to support the development of a mechanism for the
valuation of variations on civil engineering works.
The development of such a mechanism involved knowledge acquisition from
experts/practitioners in the field. Primary data was collected through a questionnaire
survey of quantity surveyors in the UK, resulting in the development of a best practice
model for preparing quotations, negotiation model, and decision-making model. The best
practice model aimed to provide a guideline to prepare quotations with higher likelihood of
being accepted. The negotiation model aimed to enable the project stakeholders to better
understand the negotiation process and so lead towards an amicable agreement. The
decision-making model aimed to provide a decision-making tool for the project
stakeholders to reach a more objective decision in valuing variations. Following internal
validation of the findings, the models were incorporated into a Knowledge Based System
(KBS) to preserve the captured knowledge and to enable effective dissemination.
The KBS was developed using Java Server Pages (JSP) technology and also MySQL. The
development of the KBS applied a user-centred approach in which user orientation, user
acceptance, and user involvement of the system were paramount. Follow-up interviews
were conducted with a smaller group of experts/practitioners to demonstrate and externally
validate the KBS.
Findings from these interviews led to improvements to the KBS, and ultimately
demonstrated the robustness and validity of the system. The KBS can be used by project
stakeholders (i. e. contractors, engineers/consultants, and employers) to reduce or at least
minimise conflicts and disputes in the valuation of variations, particularly on civil
engineering works. The KBS developed in this research could be expanded to encompass
various other types of works (other than excavation works) and procurement routes (other
than traditional procurement using the ICE 7th Measurement Version, 1999). Additionally,
there is scope to develop interfaces to link the KBS to various other systems such as CAD,
estimating tools and project management scheduling in order to deliver a fully integrated
package in valuing variations on construction projects.