When an observation plan is checked the Application Server will first get all features that the observation plan applies to (as defined by the applicability rule and applicability filter of the feature directive). The plan can only be evaluated if the user who initiated the checking has the feature permission Read observations (3) on each of these features.

For each time interval defined by the observation plan and for each feature the plan applies to the Application Server will then count the number of observations with a sampling time stamp in that time interval.

If the Only Approved flag is set for an observation plan only approved observations will be counted.

The Erroneous handling setting for an observation plan instructs the Application Server how to handle erroneous observations. The default setting is to count both erroneous and non-erroneous observations. However you can also specify that only erroneous, only non-erroneous observations are counted. Using this setting you may also define an observation plan that will identify too many erroneous observations as plan violations.

If the number of observations found in a time interval is not between the minimum and maximum specified by the observation plan, the Application Server will treat this as a violation of the observation plan. Violations for a plan will be stored associated with that plan. Each violation will record the feature where the violation occurred, the time span in which the violation occurred and the difference between the plan and the actual number of observations. This difference is a negative number if the number of real observations is less than the minimum specified by the plan or a positive number if the number of real observations is more that the maximum specified by the plan.

The checking of an Observation Plan is always done as a job. Whenever an observation plan is evaluated the Application Server will first delete the results of previous evaluations. As the plan gets evaluated all violations are found are stored with the plan, i.e. as long as the evaluation of the plan is not finished the results do not necessarily represent all violations.

The checking of an observation plans can be automated using a stored job definition of type Check Observation Plan.