Traditional project delivery models and the use of unit price or lump-sum contracts are regularly associated with cost and schedule overruns on major projects. Innovative delivery mo-dels offer an alternative. However, proving their effectiveness is difficult due to the small number of projects and lack of com-parability. This article presents a study comparing an innovati-ve delivery model with a traditional delivery model. Both mo-dels were used in the same project for the same structure: the 21.5 km long headrace tunnel of a hydroelectric power plant lo-cated at river Inn. The tunnelling was conducted using two double-shield tunnel boring machines in counter-heading mode. The construction commenced under a traditional unit price contract (UPC). This contract was cancelled by mutual agreement after a total of 3.5 km of tunnelling. To continue the drive with a new construction company using the existing site logistics, the innovative TIWAG alliance contract (AC) model was chosen for the first time in Austria. By means of probabilis-tic analysis and modelling of each complete drive in each model a comparative study was performed. For a complete tun-nel drive in the alliance model, the modelling results indicate an expected reduction in construction time of 15 to 22 %.    «

Traditional project delivery models and the use of unit price or lump-sum contracts are regularly associated with cost and schedule overruns on major projects. Innovative delivery mo-dels offer an alternative. However, proving their effectiveness is difficult due to the small number of projects and lack of com-parability. This article presents a study comparing an innovati-ve delivery model with a traditional delivery model. Both mo-dels were used in the same project for the same structure: the...    »