Bottlenecks

Once you've identified the time each patient spends at a certain step, you can identify which takes the longest.

NOW, you have identified the bottleneck.

Everything is dependent upon this bottleneck.  Recall the rate limiting step (RLS) in chemistry.  This step is typically a catalyst or rare substrate.  It's the process that S - L - O - W - S  everything else down.  In the ED, this may be: time to get a lab report, a 5150 bed, or the the on-call dialysis nurse.

Use a multi-perspective approach by including RNs, Techs, ICU docs, etc. to reduce the time it takes in the slowest step.  This can be challenging, but will reap huge rewards.

Lather, rinse, & repeat.