Description
Subtract forecastFinish from promisedAt for signed slack.
Schedule differences use a common time coordinate and may preserve negative slack or lead times. A scalar lag or float term does not recalculate a full dependency network.
Subtract forecastFinish from promisedAt for signed slack.
When to use this tool
Use Work Item Slack To Promised Date when you need one explicit scheduling or delay-budget component.
How to use the tool and how it works
- Enter promisedAt, forecastFinish. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read slack. Use the output convention below.
Subtract forecastFinish from promisedAt for signed slack.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| promisedAt | Promised At | Required. Finite number. |
| forecastFinish | Forecast Finish | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| slack | Slack | Required. Finite number. |
{
"input": {
"promisedAt": 20,
"forecastFinish": 17
},
"output": {
"slack": 3
}
}Limitations and assumptions
- Use a common timestamp or day coordinate; the result is not working-calendar float or a probability of on-time completion.
- 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
Use a complete dependency plan and working calendar to assess critical paths, resource constraints, and completion forecasts.
References
Similar or alternative tools
- Critical Ratio Remaining Work Days
Divide signed daysToDue by positive remainingWorkDays for criticalRatio and subtract remaining work from days to due for slackDays.
- Milestone Delay Float Consumption
Use min(delayDays, totalFloat) for consumedFloat, max(0, totalFloat - delayDays) for remainingFloat, and the reverse excess for unabsorbedDelay.