Description
Divide nonnegative wip by positive throughputPerHour for impliedFlowHours.
Queue identities compare flow, inventory, and service capacity under a defined system boundary. Compatible long-run averages and a mean-load inequality are narrower than a complete waiting-time model.
Divide nonnegative wip by positive throughputPerHour for impliedFlowHours.
When to use this tool
Use Littlelaw Wip Throughput Time Identity when you need one queue-load or flow-identity diagnostic.
How to use the tool and how it works
- Enter wip, throughputPerHour, observedFlowHours. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read impliedFlowHours, identityResidual. Use the output convention below.
Divide nonnegative wip by positive throughputPerHour for impliedFlowHours. Return wip - throughputPerHour × observedFlowHours as identityResidual.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| wip | Average work in process for the same system and flow population. | Required. Finite number; minimum 0. |
| throughputPerHour | Positive average throughput in the WIP unit per hour. | Required. Finite number; strictly above 0. |
| observedFlowHours | Average flow time in hours under the same system boundary. | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| impliedFlowHours | Implied Flow Hours | Required. Finite number. |
| identityResidual | Identity Residual | Required. Finite number. |
{
"input": {
"wip": 100,
"throughputPerHour": 20,
"observedFlowHours": 4
},
"output": {
"impliedFlowHours": 5,
"identityResidual": 20
}
}Limitations and assumptions
- WIP, throughput, and time must be compatible long-run averages for the same system boundary; a numerical identity does not establish steady conditions or causation.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Validate arrival and service assumptions, stability, and system boundaries using an appropriate queueing analysis.
References
Similar or alternative tools
- Queue Utilization Service Rate Gap
Multiply servers by positive serviceRatePerServer for capacity.
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Multiply nonnegative occupancy by nonnegative duration for occupancyTime.