- Implementing work-in-progress (WIP) limits results in improved efficiency and productivity over allowing unlimited WIP, with average cycle times improving by 28-59% and predictability increasing by 65-89%. - The slack time introduced by WIP limits drives continuous improvement efforts and allows teams to help each other, learn, and make system improvements. - While WIP limits can result in a small 1% increase in the cost of blocked or idle work, they provide significant value by reducing cycle times and improving predictability.