'Large float' quality metric
Use this metric to check the proportion of tasks that have an amount of float less than a given duration. A high proportion of tasks with a large amount of float can indicate incomplete logic in a schedule, for example tasks without successors.
With the duration set to 44d and the pass and fail boundaries set to 100.00%, this metric meets the requirements of CIOB stress test 6 (Float). With the duration set to 44d and the pass and fail boundaries set to 95.00%, this metric meets the requirements of DCMA test 6 (High float).
Example of tasks with a large amount of float
In the following illustration, Task 3 has 44d of float, Task 4 has 45d of float and Task 5 has 42d. If 44d was the given duration in the settings of this quality metric, tasks 3 and 4 would be considered to have large float and would fail this metric:
You can change the impact that this metric has on the weighted total result of a quality check by entering a factor by which the quality metric should be multiplied in the Weighting field. For the weighting to have any effect, a quality check must have more than one quality metric.
Pass and fail criteria
| Pass or fail? | Criteria |
|---|---|
| Pass |
A project passes this metric if the percentage of tasks that have float less than the given duration is greater than or equal to the pass boundary percentage.
For example, if the duration was set to 44d and the pass boundary was set to 90.00%, a project would pass this metric if 90.00% or more of tasks had float of 44d or less. |
| Fail |
A project fails this metric if the percentage of tasks that have float less than the given duration is less than the fail boundary percentage.
For example, if the duration was set to 44d and the fail boundary was set to 80.00%, a project would fail this metric if less than 80.00% of tasks had float of 44d or less. |
| Neither pass nor fail | If the percentage of tasks that have float less than the given duration falls between the pass and fail boundary percentages, the result is neither a pass nor a fail, but somewhere in between. |
Default suggested settings
- Duration: 44d.
- Pass boundary: 90.00%. A project will pass this metric if 90.00% or more of tasks have float of less than 44d.
- Fail boundary: 80.00%. A project will fail this metric if less than 80.00% of tasks have float of less than 44d.
The following table shows whether some example projects would pass or fail this metric using these settings:
| Percentage of tasks with float of less than 44d | Pass or fail? |
|---|---|
| 0.00% | Fail |
| 50.00% | Fail |
| 79.99% | Fail |
| 80.00% | Neither pass nor fail |
| 89.99% | Neither pass nor fail |
| 90.00% | Pass |
| 100.00% | Pass |
Suggested settings to meet the requirements of CIOB stress test 6 (Float)
- Duration: 44d.
- Pass boundary: 100.00%. A project will pass this metric if all tasks have float of less than 44d.
- Fail boundary: 100.00%. A project will fail this metric if any tasks have float greater than or equal to 44d.
The following table shows whether some example projects would pass or fail this metric using these settings:
| Percentage of tasks with float of less than 44d | Pass or fail? |
|---|---|
| 0.00% | Fail |
| 50.00% | Fail |
| 99.99% | Fail |
| 100.00% | Pass |
Suggested settings to meet the requirements of DCMA test 6 (High float)
- Duration: 44d.
- Pass boundary: 95.00%. A project will pass this metric if 95.00% or more of tasks have float of less than 44d.
- Fail boundary: 95.00%. A project will fail this metric if less than 95.00% of tasks have float of less than 44d.
The following table shows whether some example projects would pass or fail this metric using these settings:
| Percentage of tasks with float of less than 44d | Pass or fail? |
|---|---|
| 0.00% | Fail |
| 50.00% | Fail |
| 94.99% | Fail |
| 95.00% | Pass |
| 100.00% | Pass |
Does the metric force a project to be rescheduled?
Yes. If you include this metric in a quality check, the charts and summary groups that are included in the scope of the quality check are rescheduled automatically when you execute the quality check.
Suggested actions if a project fails this metric
If a project fails this metric, select the metric in the Quality Check Results dialog and click Show Failing Tasks to view the tasks that have failed the metric.
You could take the following actions to remedy the failing tasks:
- Check the failing tasks' incoming and outgoing links to ensure that tasks are linked correctly, and amend the links if necessary.
- Check any constraint flags on the failing tasks and remove any constraints that are causing tasks to have large float unnecessarily.
Introduction to schedule quality checking