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littles_law_flow_time

software_engineering::flow_framework

Function littles_law_flow_time 

Source 
pub fn littles_law_flow_time(wip: f64, arrival_rate: f64) -> Option<f64>
Expand description

Little’s law, solved for flow time: flow time = WIP / arrival rate.

The inverse of littles_law_wip, useful for checking whether measured flow load, arrival rate, and flow time are internally consistent, or for predicting flow time from a target WIP and known arrival rate.

§Arguments

  • wip — flow load (work in process).
  • arrival_rate — new items entering the value stream per unit time.

§Returns

Some(flow time), or None when arrival_rate is zero.

§Examples

use software_engineering::flow_framework::littles_law_flow_time;

// WIP of 24 items at an arrival rate of 3 items/day implies 8 days flow time.
assert_eq!(littles_law_flow_time(24.0, 3.0), Some(8.0));
assert_eq!(littles_law_flow_time(24.0, 0.0), None);