The relative impacts of selected practices on project cost and schedule

Abstract

Many studies reveal the positive impact of practices use on overall project performance, resulting in a consensus opinion in the industry that implementation of certain practices leads to improvement; yet there have been no definitive studies reporting in a quantitative manner, the relative impact of practices on different project objectives. This study develops models using multiple descriptive discriminant function analyses that divide project cost and schedule performance into four different performance groups. The study then examines the practices that discriminate among these four groups. Finally these results are summarized into a practice use index categorization for project cost and schedule performance. Critical practices indicating dominant impact on both cost and schedule performance are pre‐project planning, project change management and design/information technology practice. Team building practice is a cost‐beneficial practice and zero accident techniques practice is a schedule‐beneficial practice, while constructability practice has a balanced bottom line impact on both cost and schedule.

Keywords:

• Cost
• discriminant function analysis
• practices
• relative importance
• schedule

Notes

Notes: ^aheavy industrial projects are the reference group.

^bgrass roots projects are the reference group.

^cless than $15MM projects are the reference group.

^dCost 1 variable means between $15MM and $50MM projects.

^eCost 2 variable means between $50MM and $100MM projects.

^fCost 3 variable means greater than $100MM projects.

^gdomestic projects are the reference group.

Notes: ^aCost growth = (actual total project cost – initial predicted cost) / initial predicted cost.

^bSchedule growth = (actual total project duration – initial predicted duration) / initial predicted duration.