Your project team achieved their goal, Congratulations!
Now what happens? The team assumes all the improvements will stick and everyone will readily adopt the new standardized work. They want to sustain the improvements, or do they? Sustain is to keep in existence; maintain, continue, or prolong.
Perhaps instead of sustaining, the team would like to continually improve? Continual improvement is the ongoing, incremental improvement of processes that lead to achievement of higher levels of performance. Do you seek to maintain or keep getting better?
If you are interested in advancing beyond sustaining to continually improving, here are a few features to establish with the team and actively pursue: