Project health

Activity Center > Projects

 

The health of a project is based on two indices: SPI and CPI (See SPI and CPI thresholds for more details).

 

CPI calculated as follows:

 

1. If Hours left = 0, the following formula is used:

 

2. If Hours left > 0, the following formula is used:

 

index_formula_cpi_HLnotzero_sm

 

SPI is calculated using the formula:

index_formula_spi

where

 

StartDate, EndDate, Progress, HoursLeft, and ActualHours are project parameters,

EstimatedHours is a total of estimated hours of all the project's activities plus the project's own estimated hours, and

CurrentDate is the current date.

 

 

 

pencil

Project starting today has SPI=1 even if its progress is zero.

 

 

"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

Comment

Both indices are at or above their thresholds

evagreen

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.

evayellow

Activity/Project is at moderate risk (CPI is good and SPI is bad, or vice versa)

Both indices are below their thresholds.

evared

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.

 

 

Calculating CPI and SPI individually

 

Use 'Allow calculating CPI and SPI individually' (Settings > General > Advanced settings > Project Health (Earned Value Analysis) settings) to make sure one of the indices is calculated when the other one is unavailable.

 

Threshold

 

The default threshold for both CPI and SPI is 1.

 

The threshold is a value you set to match CPI and SPI against.

 

Generally, the higher the threshold the stricter your requirement for cost or schedule performance will be.

 

However, setting the thresholds needs to be done with care. For example, 'having a CPI that is very high (in some cases, very high is only 1.2) may mean that the plan was too conservative, and thus a very high number may in fact not be good, as the CPI is being measured against a poor baseline. Management or the customer may be upset with the planners as an overly conservative baseline ties up available funds for other purposes, and the baseline is also used for manpower planning.' (a Wikipedia article on EVA).

 

pencil

If a project has zero Estimated Hours and/or 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.

 

pencil

Only projects with the following characteristics are used in the calculation:

 

1.

Project's start date is preceding the current date so the project is ongoing.

2.

Project's status Is open or equal to open - those with a status equal to completed or on hold are not included in the calculation