Method for elaborating operational Bill of quantities through BIM authoring software

Abstract

The operational bill of quantities is an effective tool in cost management, since activities are segregated according to the production process. However, this feature may generate a long bill of quantities structure. The use of Building Information Modelling (BIM) allows budget information to be inserted into the models, allowing automatic quantity takeoff and understanding of the budget considerations through 3D visualisation. The objective of this study is to develop a method to prepare the operational bill of quantities through BIM that allows clarification of the calculation considerations and automation of the takeoff process. The development of the studies allowed the preparation of a proposal of a BIM modelling method. The evaluation of the proposed method indicated: (a) a lack of classes of objects able to represent the activities of the operational bill of quantities. The objects have no relationship with each other, leading design changes to require manual adjustments; (b) although the modelling using custom parameters did not permit 3D visualization, it proved to be a simple alternative for applying operational approach to quantities takeoff. The proposed method did not adequately support the choice of the best way of modelling (using objects or parameters). This deficiency demanded adjustments to the proposed method, incorporating guidelines to support the choice.

Keywords:
Cost management; Operational bill of quantities; 5D modelling