Site overheads: The lost dimension of improved productivity?

Paper in proceeding, 2021

Contractors routinely use site resources, such as site accommodation and fences, but not necessarily in an efficient manner. Often only loosely calculated the costs are accounted for as site overheads. The aim of this paper is to scrutinize these types of costs theoretically; empirically and analytically in the context of a Swedish contractor; and to improve the definition and categorization of these costs. Internationally, in practice and literature, there are many definitions including 'overheads' and 'site preliminaries.' In Sweden a frequent term is 'allmänna kostnader' (AK); i.e., 'common cost'; which is used by the case company. The study consisted of a literature and documentation analysis; including waste theory and costing methods; interviews; a survey and a qualitative analysis. This helped understand what costs are included in AK. An official company AK definition proved insufficient as employees used it very differently. Managers categorized resources differently from project to project, making comparison and identification of efficiency improvements difficult. A less ambiguous definition and structure of AK; was developed; focusing on the operating cost on-site; rather than any particular activity or zone. Activity-based costing and digital aids such as EquipmentLoop may improve the understanding of costs and allow more accurate estimation.