Building Design Management (DM) is challenging due to the fragmentation of project partners, the iterative nature of design and the tradition of informal management of designers. Therefore, many contractors do not trust the promises of designers and protect the construction schedule with schedule buffers that increase project lead times. To act upon this situation, several researchers have suggested using the Last Planner™ System (LPS) as a method for DM. Using two case studies, we present how the use of the LPS method as a tool for Daily Management (DAM) increases the reliability of the design and how, correspondingly, not using it can affect design reliability. So far, very little attention has been paid to the role of DAM in DM, and this short article seeks to provide new insights into this research gap for both researchers in the field and DM professionals. These early and exploratory results, despite the limited number of cases, can be utilised in further research as well as in practical project management, especially when the reduction of schedule buffers between construction and design is targeted.

Procurement and construction work depend on error-free and on-time designs. However, the design process may be erroneous and behind schedule, which often causes cascading delays and problems in the construction process. Hence, when a major delay occurs, practitioners often query the design process, and much time and many resources may be required to find the root cause. However, minor delays and mistakes that occur in everyday work are not usually investigated, even though they can contain information necessary to avoid significant adverse events. This study aimed to determine how three deviations that occurred in a normal, wellprogressing project can be investigated using two different methods, as well as the significance of small errors and events in preventing larger errors and events in the future. Root cause analysis and functional resonance analysis were the research methods. The findings of this study showed that slight variability in trivial design and design management tasks generated a considerable number of unnecessary tasks and delays. Therefore, examining variability in the outputs of tasks could benefit designers and design management.