This paper presents findings of a study about how to extend the use of Takt-time planning in construction projects. The study is based on analysis of two construction projects involving non-repetitive work that, after failing to use Takt-time planning, had to return to ordinary methods of production. To uncover causes to the problems, the research method Theory-building process tracing is used.
Results show that extended use of Takt-time planning presupposes effective coordination in the projecting process and a proactive and well organised production control in the construction phase. It also presupposes high involvement of the craftsmen and crew-leaders in the Takt-time planning and production.
The method of theory-building process tracing is transferred from political science and historical studies to construction projects. The research method offers a unit of hypothesis testing and cumulative practical theory development, which can be of general value for construction research. Although the validation of the present empirical results is thorough, based on interviews and workshops, the researchers own observations of the processes studied could have been more extensive.