Factors impacting construction project duration: a comparison between France, Germany and the u.k.

A survey of contractors planning engineers in France, Germany the U.K. indicates significant differences between projected completion times for an identical model building. Completion times are shortest in France, followed by Germany and then the U.K. yielding means of 13, 18 and 22 weeks respectively. Investigations to elicit performance affecting resource utilisation factors provide some significant findings. The productivity rates for formwork operations, particularly those provided for floor slabs, correlated with completion times. This operation apparently provides the key to optimum completion times for high rise in situ construction. Analysis of variance provides evidence to indicate that preferred options for two particular construction methods can drastically impact upon completion times, these being preferred transportation and formwork (to columns) solutions. Shorter completion times were associated with tower crane\skip transportation solutions and, proprietary formwork. In terms of labour utilisation two factors demonstrated a significant relationship with project duration, namely numbers of supervisory personnel and allowance for daily relaxation\rest times. Shorter completion times were a feature of reduced supervisory numbers and longer periods of relaxation. Construction contractors may wish to give consideration to these important aspects, when planning to undertake such projects and earliest completion is paramount.