Projekteringsbristers påverkan på produktionsskedet : En studie med fokus på marktekniska undersökningar i utförandeentreprenader

Sammanfattning

In design-bid-build contracts, the contractor’s tender and production planning are based on the tender documents and construction documents provided by the client. If these documents do not reflect the actual ground conditions, this may lead to production disruptions, quantity deviations, variation orders, and time and cost increases. The purpose of this study is to examine how deficiencies in ground-related information in construction documents affect the production phase in civil engineering projects. The study also analyses how such deficiencies influence quantity deviations and variation orders, and how responsibility for identifying and managing errors is distributed between different actors. The study was conducted as a multiple-case study using both qualitative and quantitative methods. The quantitative part is based on a document study of four civil engineering projects within Skanska Väg och Anläggning, including quantity calculations, tender documents, construction documents, measurement records and site diaries. The qualitative part consists of semi-structured interviews with actors from different parts of the construction process. The results show that deficiencies in ground-related information mainly affect work related to soil excavation, rock excavation and contaminated materials. These deficiencies may result in increased quantities, additional machine and labour hours, replanning and variation orders. The study also shows that responsibility should be understood as a chain of responsibility involving the client, designer, geotechnical engineer and contractor. The conclusion is that more reliable ground investigations, clearer risk reporting, improved coordination and systematic feedback from completed projects can reduce the risk of quantity deviations, variation orders and production disruptions.