Productivity improvement within the construction industry has addressed issues that are predominantly associated with activities and tasks on construction sites, and less so in the office work. The lack of an understanding of the proportion of productive time during working hours for designers, as well as the measurement method forms a significant gap in the knowledge of the design process. Productivity management cycle comprised of 4 phases: measurement; evaluation; planning; and improvement. Therefore, measurement becomes essential in productivity improvement. This study identifies the lack of defined duration for design task and measurement of design activity time as an essential gap in the productivity knowledge that relates to designers.