Availability
Important
The project health is calculated independently of the health of its activities. Refer to this article to learn how activity health is calculated.
Overview
In terms of EVA (earned value analysis) the health of a project is based on two indices: SPI and CPI.
CPI calculation
A project's CPI is calculated as follows:
1) If Hours left = 0, the following formula is used:
2) If Hours left > 0, the following formula is used:
,
where:
- Progress, Actual Hours and Estimated Hours are project parameters,
- Estimated hours is a total of estimated hours of all the project's activities plus the project's own estimated hours, and
- Actual hours is a total of actual hours of all the project's activities.
SPI calculation
SPI is calculated using the formula:
where:
- Start date, End date, Progress*, Hours left, and Actual hours are project parameters,
- Estimated hours is a total of estimated hours of all the project's activities plus the project's own estimated hours, and
- Current date is the date of the present day.
Important
A project whose start date is the current date has an SPI value equal to the default one as set in the Company settings > Account settings, even if its progress is 0.
"Definitely bad" index
- SPI is "definitely bad" when the project's end date is in the past.
- CPI is "definitely bad" when Actual hours > Estimated hours and Hours left = 0.
Health color coding
The chart explains the color coding being used to show what health a given activity/project has:
| CPI/SPI values | Color code | Personal schedule performance |
| Both indices are at or above their thresholds. | Healthy project (when one of the indices is good and the other is unavailable*, or both SPI and CPI are good). | |
| One index is below and the other is above its threshold or N/A. | Activity/Project at moderate risk (CPI is good and SPI is bad, or vice versa). | |
| Both indices are below their thresholds. | Project is at high risk (both CPI and SPI are below the threshold, or either SPI or CPI is definitely bad (DB)). | |
|
*
The conditions under which SPI and CPI are not calculated (not available) are given in the notes below.
|
||
CPI and SPI thresholds
The default threshold for both CPI and SPI is 1.
The threshold is a value you set to compare against CPI and SPI. A higher threshold means stricter requirements for cost or schedule performance.
Calculating CPI and SPI individually
Use "Allow calculating CPI and SPI individually" (Company settings > Advanced settings > Project health settings) to make sure one of the indices is calculated when the other one is unavailable.
If a project has zero actual hours, CPI is not calculated at all. Such a project will be "green" if its SPI is above the threshold. If SPI is below the threshold, the project is "yellow" (at risk) if it is on schedule, or "red" (troubled) otherwise.
Only projects with the following characteristics are used in the calculation:
- Project's start date is preceding the current date, so the project is ongoing, and
- Project's status is treat-as-open or treat-as-hold – those with a status treat-as-complete, e.g., Closed, Completed, etc., are not included in the calculation.
SPI and date rollup
Closing an activity before or after its planned end date can have different results for the project's SPI, depending on whether:
- date rollup is enabled for the project;
- at least one activity in the project has estimated hours;
- the project's end date changes as a result of closing the activity.
Examples
Initial conditions: Task A defines the project’s end date. The project's date rollup is ON.
Case 1: User is closing Task A before its planned end date: now Task B defines Project End Date, in consequence, the project's end date has moved back (which makes SPI worse). But the project's progress has also improved highly, that’s why its SPI improved somewhat, too.
Case 2: If the user is closing Task B instead, it wouldn’t affect the end date (still determined by Task A), but improves the project's progress, consequently, SPI improved again and even more.
Case 3: The user is closing Task A after its planned end date: now Task B defines the project's end date, as a result, the project's new planned end date has moved forward (which makes SPI better). In consequence, the project's progress has also improved, causing SPI to improve as well.