This paper introduces a new concept termed the continuous task-string (TS), which consists of specific combinations of preconstruction planning (PCP) and project execution (PE) tasks that, when linked together have a high probability of improving project performance. Through a two-stage process, 3,910 combinations of 46 and 85 PCP and PE tasks, respectively, were reduced down to 239 validated task-strings. These task strings were evaluated by electrical construction professionals to statistically quantify the potential influence of the task strings on cost and schedule success. Statistical analysis supported the hypothesis that those task strings which were viewed as being more important to cost and schedule success would also be viewed as being more critically interdependent. Hence, completion of the PCP-PE task combination was viewed as being a key ingredient for project success. The research reported in this paper provides a strong theoretical foundation for further studies on the influence of task strings on project performance. Ultimately, by elucidating the relationship between preconstruction planning and project execution tasks, the research reported in this paper can help electrical contractors achieve project performance improvement through effective task-level strategies.