Function flow_time 

pub fn flow_time(entry: f64, delivery: f64) -> f64

Flow time: total elapsed time from a flow item entering the value stream to its delivery.

Flow time (chapter 2.4) spans the whole value stream, from a business need being identified to a customer receiving value — broader than crate::cycle_time, which covers only the engineering stages. It is conceptually just elapsed time, delivery − entry, but the definition of entry must be fixed and documented: quietly narrowing it is this metric’s central gaming risk.

Arguments

• entry — the timestamp (any consistent unit) the item entered the value stream.
• delivery — the timestamp the item was delivered.

Returns

The elapsed flow time, delivery − entry.

Examples

use software_engineering::flow_framework::flow_time;

// Entered on day 3, delivered on day 15: 12 days of flow time.
assert_eq!(flow_time(3.0, 15.0), 12.0);